Oil well drilling

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VOLUME FIVE HOISTING EQUIPMENT

OVERVIEW:

Function of Hoisting Equipment
A rig is complicated, but easier to understand if divided into related parts. In this section, we well cover the equipment used in hoisting. Hoisting equipment hangs or suspends the drill string in the hole. It also allows the driller to raise and lower the drill string into & out of the hole. Further, it allows the driller to adjust the weight on the bit, which is required to make the bit drill.

Hoisting System Components
The equipment used in hoisting is shown here: the Crown Block, the Traveling Block & Hook, the Drilling Line, the Drill Line Supply Reel, the Deadline to crown block, the Fast Line to drawworks, the Drawworks and the Deadline Anchor.

Hoisting System Operation
Here is an overview of how the hoisting system operates. The supply reel stores drilling line. To reeve the line, crew members start it at the deadline anchor. They pull the line from the supply reel and spool it around the disk on the anchor. They then lift the line to the top of the mast, to the crown block. Crew members then reeve the line several times between the crown block sheaves and traveling block sheaves. The number of times depends on how much weight the system needs to lift. In this case, they run the line 5 times between the two blocks to create 10 lines. Once they’ve strung the right number of lines, they run the line to the drawworks and firmly clamp the line to the drum. The driller then takes in the drilling line, which wraps around the drum. The driller usually takes in enough line, so that the line makes it at least 6 wraps around the drum. They then clamp the line at the deadline anchor. As the driller activates the drawworks to take in line, the traveling block moves up. The driller uses the brake to stop the traveling block at any position. When the driller releases the brake, the force of gravity pulls the traveling block down.

[TOOL BOX]: Here are the components of the hoisting system, drag the labels to the appropriate components.

CROWN BLOCK

Crown Block Operation
The rig builder mounts the crown block at the top of the mast. The crown block has several pulleys called sheaves. The block manufacturer mounts the sheaves side by side on a shaft. The drilling line runs over the grooves in the sheaves. Sometimes, like this one, the crown block has a special fast sheave. The drilling line runs over the fast sheave as it leaves or enters the side-by-side sheaves on the crown block. Crown blocks have load ratings that range from about 420 to 1400 tons (about 380-1300 metric tonnes). Sheave diameters range from 42 to 72 inches (or about 107-180 cm).

TRAVELING BLOCK & HOOK

Overview:
A traveling block also has several side-by-side sheaves. A steel housing encloses them. Crew members thread or reeve the drilling line over the sheaves. [TOOL BOX]: The crew must use drilling line that is the right size for the sheave groove that it fits in. Here are cross section of use of three diameters of drilling line. Drag each one into this sheave to see what happens. Small: the diameter of this wire rope is too small. The rope will move back & forth in the sheave groove, causing it to flatten on one side and wear out prematurely. Medium: the diameter of this wire rope is just fight. The wire rope can’t move back & forth in the groove and it won’t wear excessively on the sides of the sheave groove. Large: the diameter of this wire rope is too big. It will rub on the sides of the sheave groove and wear out prematurely. A hook is attached to the bottom of the traveling block. The hook suspends the swivel, kelly and drill string or a top drive & drill string.

Motion (Heave) Compensator
This is a traveling block on an offshore floating rig. It has a drill string motion compensator. The motion compensator is between the traveling block and the hook. Offshore floating rigs move up and down with sea movements. The motion compensator maintains drill string position by counteracting up & down vessel movement or heave. On some semi-submersibles and drill ships, rig owners mount the motion compensator on the crown or the top of the derrick.

Motion Compensator Operation
The compensator eliminates the motion of the drill string from hook to the bit. As the vessel moves up & down, hydraulic pressure inside a piston and cylinder keep the hook in a fixed position relative to the sea floor. The compensator keeps the drill bit on the bottom of the hole, within the weight on bit limits set by the driller. A typical compensator can compensate for up & down movement as much as 15-25 ft (4.5-7.5 m). Typically, two sizes of motion compensators are available: one can handle loads up to 400,000 pounds (or about 180,000kg); another one which is bigger can handle loads up to 600,000 pounds (or about 270,000kg).

Combination Hook-Block
Some traveling blocks have built-in hooks, they are single integrity unit. The combination Hook-Block is shorter, and therefore allows more traveling distance when mast height is limited. Typical combination hook-blocks have load ratings ranging from 175 tons to 650 tons (about 160- 590 metric tonnes).

Separate Hook and Traveling Block
Some traveling blocks & hooks are separate units. In this type, the bail of the hook fits into a clevis on the bottom of the traveling block. Crew members suspend the swivel and drill string from the hook. They open the hook’s latch, insert the swivel’s bail and close the hook’s latch. A safety catch ensures that the hook stays latched. Separate traveling blocks are available in load ranges from 100 to 1250 tons (or about 90 to 1125 metric tonnes). Sheave diameters range from 24 to 72 inches, 61 to 183 cm. That is 2 to 6 ft, or over half a meter to nearly 2 meters in diameter. Hooks have load ratings of from 350 to 1000 tons (about 300 to 900 metric tonnes).

Hook, Links & Elevator
The hook has two link ears. The crew attaches on piece of forged links and an elevator to the ears. They lock the links to the ears with the link-locking arms. Crew members latch the elevator to tubulars, joints of drill pipe and other types of pipe as they running into & out of the hole.

Elevator
Crew members latch the elevator around the top joint of the drill pipe. Then when the driller takes in drilling line, the traveling block goes up, raising the elevator and attached pipe. Conversely, when the driller lowers the traveling block, the elevator and attached pipe also go down.

Types of Elevators
Crew members use many types of elevators, which one depends on the kind and size of the tubulars. For example, most drill pipe and lifting subs require a center-latch bottleneck elevator. But some drill collars require a side-door collar type elevator; tubing, a light-weight pipe used in completing wells usually needs a slip type tubing elevator; casing, large pipe the crew lines the hole with requires a special heavy-weight casing elevator. The two types here are the Single-Joint, Casing Pick-Up type and the 500-ton (or 450-metric tonne) Casing Elevator-Spider.

Hook Positioner & Swivel Lock Assembly
Most hooks have two locks: a rotation lock and automatic positioner lock. Crew members use a long steel rod, called a shepherd stick or a checking hook to unlock and lock the rotation lock and the automatic hook positioner. When crew members unlock the rotation lock, they rotate the hook to make the elevator face a desired direction. Once positioned, they lock the rotation lock to keep the hook in position. Crew members can also release the rotation lock when the hook needs to rotate freely. The other lock, an optional automatic hook positioner prevents rotation of the elevator links when the hook is traveling empty. Normally, just before making a trip in cased hole, crew members unlock the rotation lock, turn the hook, and relock it, so that the elevator faces the derrick man. This makes it easy for him to latch and unlatch the elevator. If crew members are tripping pipe in open hole, they activate the automatic hook positioner. This lets the hook rotate freely when hoisting the drill string, allowing the drill string to turn in open hole as it is being pulled, keeps it from damaging the hole and prevents the reeve to drilling line from twisting. Then, when the elevator reaches the derrick man and the driller stops hoisting, the positioner automatically rotates the elevator into correct position for the derrick man.

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Hydraulic Snubber
Inside the hook is a hydraulic snubber. The snubber is like a shock absorber. It prevents drill pipe bounce and tool joint damage when spinning out the connection.

DRILLING LINE

Drilling Line
Drilling line is high strength heavy-duty wire rope. The manufacturer braids several wires together to form the rope. Drilling line comes in diameters ranging from 7/8 to 2 inches (about 22-51 mm). Crew members string or reeve drilling line between the crown block and the traveling block. The more lines they reeve, the more weight the system can support. Here for example, they reeve the line 5 times between the blocks, so that ten lines support the traveling block.

Reeving Drilling Line
Here is the crown block & traveling block strung together by drilling line. Note how the traveling block goes up & down as the driller takes in or lets out drilling line. The deadline is drilling line that runs to the deadline anchor. The fast line is drilling line that runs to the drawworks. Notice the five wraps of drilling line between the crown & the traveling block. Five wraps makes for ten lines. Ten lines can lift ten times the weight of a single line. Also notice that the crown block has one more sheave than the traveling block. This extra sheave is for the fast line.

[TOOL BOX]: This photo shows the fast line and the deadline on a rig. Using your mouse, drag each label onto the correct line, then click the “accept” button to see if you’ve gotten it right.

Supply (Storage) Reel
Drilling line comes to the rig on a large supply reel. Normally crew members string the needed amount of line through the traveling & crown blocks and onto the drawworks. Then they keep the extra line on this supply reel. The reason they keep the extra line is for a Slip-and-Cut Program.

Wear PointS on Line
As the driller raises and lowers the traveling block and its associated loads, the drilling line wears. It tends to wear more where it passes over the traveling block sheaves and the crown block sheaves. The line has to bend around the sheaves and this puts extra stress on it. The line also wears more where it reaches the end of the drawworks’ drum. It has to reverse direction here, and start back the other way on the drum. This direction change puts extra stress on the line.

[TOOL BOX]: Not only does the drilling line wear, but the sheaves do also. One thing that the crew does to prolong the life of the sheaves is to rotate the traveling block 180° degrees. Click on it and we’ll see why this is done. During operation, each sheave moves at a different speed. The one closest to the fast line moves the fastest and the one closest to the deadline moves the slowest. Since the faster moving sheaves wear quicker, the wear can be distributed evenly among the sheaves by rotating the traveling block periodically. This is often done between wells.

Slipping and Cutting Drilling Line
To distribute the wear on the drilling line, the crew slips the line a predetermined amount. Slipping the line moves the wear points on the line. To slip the line, crew members lower the traveling block to the rig floor. They then rig up a special hang line from the crown beam to the top of the traveling block. The hang line keeps the block from moving. With the block unable to move, they unclamp the drilling line at the deadline anchor. The driller then uses the drawworks to pull new line off the supply reel. The line slips through the deadline anchor and stationary traveling block. The worn line reels onto the drawworks’ drum. To keep too much line from accumulating on the drum, crew members cut off the end of the worn fast line and discard it.

[TOOL BOX]: This is an example of bird-caged or wicker wire. Bird-caged wire is unsafe and needs to be removed by slipping & cutting. Bird-caged wire is caused by sudden dropping of the traveling block. Driller should raise & lower the traveling block as smoothly as possible.

Deadline Anchor
This is the deadline anchor. It firmly secures the drilling line and keeps it from moving. Drilling line comes off supply reel, and loops several times around the anchor. The rig crew then firmly clamps the line to the anchor. The line leaves the anchor, goes through the crown & traveling blocks and then to the drawworks. Clamping the deadline to the deadline anchor mechanically isolates the drilling line from the supply reel. Because the line is stationary, it is called the deadline.

DRAWWORKS
Overview
The drawworks has a large spool or drum around which the crew members wrap the drilling line. Power from the engines or electric motors drives the drawworks’ drum. When the driller activates its control and releases the brake, the drum reels in drilling line. Reeling in drilling line raises the traveling block and whatever’s attached to it. To lower the traveling block, the driller releases the drawworks’ brake. The force of gravity pulls the block down. The driller controls the descent by applying the brake to slow or stop the downward travel. The smallest drawworks are around 550 hp, while the largest have 4000 hp, about 400-3000 KW. Small drawworks can handle wells drilled to around 3000 ft (1000m) deep; the largest can handle 40000-foot or 12000-m depth.

Braking System
When the driller moves the brake handle down, the drawworks’ brake bands exert friction on both rims of the drum. We’re only showing one rim to keep it simple. This friction slows or stops the drum. When the driller lifts the brake handle a small amount, tension on the band eases. With tension eased, the drawworks’ drum rotates a small amount to gradually lower the load. When the driller lifts the handle up fully, the bands do not touch the drum rims at all, the drum rotates freely and the load drops in free-fall.

Disk Brake System
Many new drawworks use a disk brake system. Disk brakes are more efficient than drum brakes. A typical disk brake system consists of three major components: two Disks, one on each end of the drum; a Hydraulic Operating System, which you can’t see here, and Caliper-and-Pad Assemblies. The system has 6 service calipers, 3 on each disk, and 2 emergency calipers, one on each disk. When the driller engages the brake, hydraulic pressure pushes in the pads inside each service caliper. The pads contact the disk and slow or stop the drum. If hydraulic pressure fails, the emergency caliper set automatically.

Electrodynamic Brake
Mounted on the end of the drawworks’ drum shaft, is an electrodynamic brake. It is an auxiliary brake that uses powerful electromagnets. The electromagnetic force works against the turning force of the drawworks’ drum shaft. It assists the mechanical drum or disk brake you just saw. It controls the speed of the load as it goes down. The driller can not control the load’s speed with the drum or disk brake alone. The weight of the load plus the tremendous inertia creates when moving is just too great. So the driller activates the eletrodynamic brake. The electrodynamic brake provides most of the braking force when the drawworks’ drum is turning.

[TOOL BOX]: Drag the labels to proper location to identify the components in this photo.

Latest Drawworks
The most modern drawworks’ braking system does not use an electrodynamic brake. Instead, the drawworks is powered by a special computerized motor and control system. The computer-control system allows the drive motor to power the drawworks and provide the auxiliary braking force.

Crown Saver
Mounted on the drawworks, near the drawworks’ drum, is a crown saver, or a crown O-Matic, a brand name. A crown saver keeps the driller from accidentally raising the traveling block into the crown block. It has a probe that activates an air-actuated toggle switch if the driller takes in too much drilling line onto the drawworks’ drum. Too much line indicates that the driller has raised the traveling block too high in the mast. If he raised the block any more, it would crash into the crown block, or separate the rotary hose, causing a lot of damage. Too much line on the drum activates the toggle switch. The switch then immediately engages the drawworks’ brake and disengages the drawworks’ clutch. Clutch disengagement disconnects the drawworks’ drum from its power source. The latest drawworks uses an electrically actuated crown saver system, but still maintains the pneumatic crown saver as back up.

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VOLUME SIX ROTATING EQUIPMENT, MAST & SUBSTRUCTURE

ROTATING EQUIPMENT
Overview
Some rigs use a kelly and rotary table to rotate the drill string and bit. This system consists of the Swivel and Rotary Hose, the Kelly Assembly and the Rotary Table. Some rigs use a top drive system to rotate the drill string and bit. A modern top drive, also called a power swivel, is an integrity unit that includes a Pipe Handler Assembly, Block, Swivel and a powerful Motor or motors to rotate the drive shaft. Crew members make up the drill string to the drive shaft.

KELLY & ROTARY TABLE

Kelly Assembly
Crew members make up the kelly to the swivel stem. The kelly has either four or six sides and passes through a four or six-sided opening in the kelly drive bushing. The kelly drive bushing meets with the master bushing, so when the machine inside the rotary table rotates the master bushing, the kelly drive bushing rotates the kelly and attached drill string and bit.

Kelly Detail
The kelly is flat-sided, with either a square or hexagonal cross section. It is square in this drawing. It is hollow so the drill fluid can flow through it. The kelly moves through a square or hexagonal opening in the kelly drive bushing. The kelly drive bushing meets with the master bushing in the rotary table. The rotary table turns the master bushing, the kelly drive bushing, the kelly and the attached drill string & bit. The kelly can move vertically while rotating.

Rotary Table Operation
The rotary table performs two functions. First, it transmits rotary motion to the master bushing, which drives the kelly and drill string, and with systems of slips, hangs the drill string. The master bushing goes inside an opening in the rotary table. Small master bushings are usually a solid single piece as shown here. Large master bushings are either split or hinged.
Crew members install a two piece or split insert bowl in a receptacle in the center of the master bushing. The insert bowl is tapered inside and supports the back of the slips. They come in varied sizes. The crew changes out the insert bowls to match with the types of slips in use. Insert bowls are also called inserts or bushings. Rotary tables have openings that range in diameter from 17-49 inches (43 cm to about1.2 m). The smallest can hold a nonmoving load of 250 tons (about 225 metric tonnes). The largest can hold a nonmoving load of 800 tons (about 725 metric tonnes). Some small rotaries can spin as fast as 500 revolutions per minute, rpm; large rotaries spin a bit slower, with upper ranges about 300 rpm.

Setting Slips
Manufacturers taper the inside of the insert bowl. They taper it to match the taper of the back of the slips. The slips grab the drill string and suspend it inside the insert bowl. The insert bowl fits inside the rotary table’s master bushing. Suspending the drill string in this manner allows crew members to disconnect the kelly or top drive and break out joints of drill pipe. Crew members can remove the insert bowls to provide a larger opening through the rotary table. If necessary, they can also remove the master bushing. They may have to do this to run a large hole opener bit or large casing. Casing is pipe that the crew runs to line the walls of the hole after they drill it.

Swivel & Rotary Hose
A rotary table & kelly system includes a swivel & rotary hose. The swivel has a bail, like the bail or the handle on a bucket, only much larger. The swivel bail hangs from the hook on the traveling block. The swivel allows the attached kelly & drill string to rotate. At the same time, the rotary hose conducts drilling mud into a curved pipe, called the gooseneck. The gooseneck attaches to the swivel and carries drilling fluid to the swivel via the washpipe. The rotary hose is flexible, steel-reinforced hose that allows the swivel to move up & down within the mast. A passage way inside the swivel stem conducts the high pressure drilling mud into the kelly and drill string.

Swivel Operation
Here is an isolated view of the swivel. The bail hangs the swivel from a hook, which is not shown. The rotary hose conducts drilling mud to the gooseneck. Mud flows through the gooseneck, down the washpipe, and into the stem & drill string below. Washpipe packing seals the high pressure mud in the washpipe as the stem rotates. The stem rotates on heavy-duty radial bearings & thrust bearings. The main thrust bearings support the entire weight of the drill string as it rotates. Swivels have dead load capacities ranging from 150 to 1250 tons, about 135 to 1125 metric tonnes. An oil reservoir lubricates the bearings and rotating parts.
[TOOL BOX]: Here are all the pieces of the rotating assembly. Put them together, starting from the rig floor and working your way up. Drag each piece into place with your mouse.

TOP DRIVE (POWER SWIVEL)
Overview
Some rigs use a top drive system to rotate the drill string & bit. A top drive has a powerful motor or motors, and a drive shaft. The crew attaches the drill string to the drive shaft. When the motor rotates the drive shaft, the attached drill string & bit also rotate. Crew members attach the top drive to Guide Rails or Tracks, which keeps the whole unit from rotating. With a top drive, the rotary table does not rotate the drill string.

Top Drive Advantages & Disadvantages
The most important benefit of a top drive is that it reduces drilling time. It also rotates the drill string more efficiently than the kelly & rotary table system. Further, it handles stands and pipe more efficiently. A top drive system provides more variable rotating power than a rotary table. It allows drill string rotation and circulation at any point in the hole, when tripping in, drilling, or tripping out. These features help prevent hole problems. It provides rapid response to well kicks during tripping or running casing. The driller can make up and remotely shut the built-in IBOP to stop drill string flow faster than the crew can set slips, stab and close a full opening safety valve. In highly deviated holes, it helps to prevent the pipe from getting stuck by allowing the driller to immediately ream or back ream the drill stem. If the crew can make three joint stands of pipe before drilling starts, a top drive can drill triple stands, instead of just one joint, as is necessary on a kelly drive rig. Making up 3 joint stands reduces the number of connections required to 1/3. In many cases on large offshore rigs, the crew no longer needs to lay down pipe between wells. That is the crew can set stands back vertically in the derrick, and the rig can be moved a short distance without the pipe being laid down.
Top drives have a few disadvantages. They’re more expensive to maintain and they’re very large. Because of the additional weight, the rig’s drilling line wears faster. They are more difficult to move on land rigs that must be disassembled.

Top Drive Assembly
A top drive does not use a kelly or the rotating components of the rotary table. The top drive includes a traveling block and an integrated swivel. The rotary hose conducts drilling mud to the integrated swivel via an S-pipe assembly. A passage inside the swivel drive shaft directs mud into the drill string. The top drive motor, connects to the traveling equipment at the integrated swivel assembly. Drive motor horsepower ranges from 600 up to 2100 (or 420 to 1500 KW). The motor turns the main drive shaft through a gear box or transmission. Crew members make up a saver sub on the bottom of the drive shaft and make up the drill string onto the saver sub. The saver sub cuts down on wear & tear to the drive shaft’s threads. Top drive have hoisting capacities ranging from 350 to 750 tons (or 315 to 680 metric tonnes). Guide tracks or rails in the mast keep the top drive unit form rotating as the motor in the drive shaft assembly turns the drill string. The top drive dully assembly moves up or down on the guide rails. Service loops which are bundled cables and hoses transfer the required electric, pneumatic, and hydraulic power between the mast’s standpipes and the junction boxes located on the top drive. The top drive unit also includes a pipe handler assembly that has an upper inside blowout preventer, IBOP, a lower IBOP and a torque wrench. The torque wrench makes up (or connects) or breaks out (or disconnects) joints of drill pipe. The driller controls the top drive’s operation from a console. The pipe handler assembly also includes links, an elevator, and an automatic Link-Tilt assembly. The driller activates the link-tilt assembly to position the links and elevator at the mouse hole for picking up or laying down drill pipe. The link-tilt assembly also assists the derrick man in racking stands.

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MAST & DERRICKS
Overview
The rig’s mast is a strong tower that supports the equipment attached to the traveling block & hook. Crew members sometimes use the words “mast” and “derrick” interchangeably. In reality, a mast stands independently on the rig floor and is raised as a single piece unit. In the old days, rig owners used a lot of derricks. A standard derrick as it’s called, is usually bolted together. It has four legs, beams and girds, or cross braces. Unlike the mast, the derrick cannot be lowered or raised as a single unit. Today masts are much more common than derricks.

Mast
Manufacturers usually weld and pin the mast together for easier to assembly or disassembly. A self-erecting mast may be a Cantilever type, a folding type, or a telescoping type.
[TOOL BOX]:
Transporting Mast: Once take a look at some of the alternative ways that heavy roading here can be used to transport a mast to the land rig well site. These transport methods can be used in terrain that’s fairly flat and open, like desert. Here you see a mast together with the substructure being towed in the upright position. Here is another mast being towed with its substructure. However, this one is being towed in a horizontal position. Once it’s at the well location, it will be raised up into position using the drawworks. This mast is also being towed in a horizontal position, but its substructure is towed separately. The mast will have to be mounted and raised on the substructure once it arrives at the well location.

Height & Capacity
A mast or derrick is tall, normally having a clear height from 100 to 160 ft (30-50 m). They’re also strong; they’re able to support static weights ranging from 275,000 pounds to 31/4 million pounds (or 125,000 to 1.5 million kg). A rig’s mast must be tall enough to allow crew members to set back drill pipe, tubing and other tubulars they pull out of the hole during a trip out. It also has to be tall enough to allow the driller to raise the traveling block above the height of the derrick man’s monkey-board.


Stands
With the traveling block high in the mast, and the elevator at the derrick man’s position on the monkey-board. The derrick man sets back drill string elements or stands. Most rigs pull three-joint stand of drill pipe and drill collars. A three-joint stand is three made-up joints of drill pipe or collars. Small rigs may pull two or even one joint stand. In rare cases, a really large rig may pull four-joint stand. Regardless of the number of joints, pulling pipe in stands instead of a single joint at a time speeds up the tripping process.

Crown Walkaround (Water Table)
The working platform at the top of the derrick or mast that permits access to the crown block is called the walkaround. It is also called the water table.

Monkey-board
The monkey-board is the derrick man’s working platform when crew members pull pipe or run it back into the hole. The derrick man sets stands of pipe back into a finger board, a platform with projections that holds the top of the pipe in place as it stands in the mast.

Stabbing Board
A stabbing board is similar to the monkey-board. It is a small platform in the mast or derrick about 30-40 ft (or 9-12m) above the rig floor. A drilling crew member, usually the derrick man, works on the platform when running casing or tubing. The derrick man guides the top of the casing or tubing from the stabbing board. The crew member calls the stabber, adjust the stabbing board’s height with a hydraulic, electric or air-powered motor. The height varies depending on the length of the casing or tubing being made up and running into the hole.

[TOOL BOX]
Here is a picture of a rig. When you’re given a rig component, click on the photo where the component is located.

SUBSTRUCTURE
Overview
The substructure is a rugged set of beams. It supports the mast or derrick and the heavy hoisting & rotating equipment. It also supports the drilling tubulars on the rig floor. It must be high enough to accommodate the blowout preventer stack underneath the rig floor.

V-Door, Pipe Ramp & Catwalk
Crew members hoist pipe and equipment from the catwalk up to the rig floor by raising it up the pipe ramp. They hoist it onto the rig floor through the V-door.

[TOOL BOX]
The V-Door takes its name from the early days of the oil -----. On old standard derricks, this opening looked like a large up side down “V”. The name’s stuck, even though today the opening may not look much like a “V”.

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VOLUME SEVEN PIPE HANDLING EQUIPMENT
PIPE HANDLING
Overview
The rig crew needs pipe handling equipment for several reasons. One is to make a connection, to add a joint of pipe as the hole deepens; another is to trip the pipe, to take the pipe out and put it back in the hole, so they can change out bit, put a new bottom hole assembly and drill string or perform any other action that requires the drill string’s removal from the hole. Crew members can make connections either by using a kelly & rotary table system or a top drive unit. Handling pipe, tripping it in and out of the hole, connecting joints together, and moving it around the rig floor requires a lot of equipment. Included in this equipment are the elevator, slips, tongs, power tongs, spinning wrenches, catheads, kelly spinner, Iron Roughneck, rathole, mousehole and air hoist. Much of this equipment is controlled at the driller’s console. Transferring pipe from the deck to the rig floor may also involve special handling equipment.
[TOOL BOX]: Here is a little exercise to help you learn the names of all this equipment. When you’re given the name of a component, click on it with your mouse. If you don’t get it the first time, keep trying until you do.

PIPE HANDLING OPERATION

Making a Connection with Kelly
Notice that the kelly is drilled down, that is the rig can drill no deeper without adding a joint of pipe. Here’s the sequence to make a connection with the kelly and rotary table system. The driller picks up the kelly with the hoisting system and the floor crew sets the slips to suspend the drill string in the hole. Using large wrenches, called tongs, the crew loosens or breaks out the kelly from the drill string. They latch one set of tongs called the back up tongs around the drill pipe to keep the pipe from turning when they apply break out torque with the second set of tongs, called the lead tongs.
The driller actuates the break out cathead, which is an automatic winch on the drawworks. The break out cathead pulls a line attached to the lead tongs and loosens the connection. With the connection loosened, the driller spins put the drill pipe from the kelly, usually by slowly turning the rotary table. The back up tongs latched onto the kelly saver sub, keeps the kelly from turning as the pipe spins out. The crew then moves the kelly over to the new joint of pipe placed in the mousehole, a lined opening in the rig floor that holds the joint to be added. They stab the kelly into the new joint. They latch the back up tongs around the tool joint of the pipe joint in the mousehole. The back up tongs keep the joint from turning as the driller spins up the kelly into the joint, using the kelly spinner. The kelly spinner is a pneumatic or hydraulic device mounted near the top of the kelly. To make up the kelly onto the drill pipe to final tightness, the crew latches the lead tongs around the kelly while holding the back up tongs on the pipe’s tool joint box. The driller then actuates the make up cathead on the drawworks. The make up cathead pulls a chain attached to the lead tongs and tightens the kelly onto the drill pipe joint. The driller, using the hoisting system, picks up the kelly and new drill pipe joint out of the mousehole, and the crew guides it to the drill pipe joint, hanging in the rotary table. The crew stabs the new joint into the suspended joint, and the driller actuates the kelly spinner to spin up the new joint.

[TOOL BOX]: Click on the play button to see a video of the kelly being made up.

Once bond up, the crew latches the back up & lead tongs around the joints to make them up to final tightness. With the joints made up, the driller picks up the kelly and drill string. The crew pulls the slips, and the driller lowers the kelly and meets the kelly drive bushing with the master bushing. Drilling then continues.

Making A Connection with a Top Drive
Here is how to make a connection using a top drive. After drilling down the stand, the crew sets the slips. The driller stops circulation, and the crew breaks out the saver sub from the drill pipe using the torque wrench and the top drive’s pipe handler. The driller then uses the top drive’s drilling motor to unscrew the connection. The driller picks up the top drive and a crew member opens the drill pipe elevators to allow it to pass over the box of the pipe, setting in the slips. The driller raises the top drive assembly to the monkey-board. The derrick man latches the triple drill pipe stand in the elevators. The elevators pick up the stand and the floor crew stabs the bottom pin into the drill pipe box in the rotary table.

[TOOL BOX]: Click on the play button to see the joint being stabbed into the drill string.

The driller lowers the top drive to stab the saver sub into the box at the top of the stand. Using the top drive’s drilling motor, the driller spins up both the top connection and the lower connection at the rotary table. The rotary helpers use back up tongs to keep the connection stationary as the pipe spins. Finally, the driller begins circulation, the crew pulls the slips and drilling resumes.

[TOOL BOX]: Here is your chance to supervise the making of a connection, using a top drive. The stand has been drilled down and it’s time to set the slips. The top drive has already been broken up from the drill string and attached to the stand of pipe in the mast. Raise the stand of drill pipe by clicking on the top drive… Good! Now lower the tool joint on to the drill string by moving the top drive downwards with your mouse. Activate the top drive by clicking on it with your mouse. Lift the drill string by moving the top drive upwards. And finally, remove the slips by dragging them out of the insert bowls. Excellent work! Now you are ready to make hole.

Tripping Out with Kelly
Here is a crew on a rig with the kelly & rotary table system tripping pipe out of the hole. That is the rotary helpers, the derrick man and the driller are working together to pull the drill string from the hole. Maybe to change the bit, or something similar.
First, the crew suspends the drill string in the hole with slips. Then they break out the kelly assembly. They swing the assembly over to a lined hole, called the rathole, and the driller lowers the assembly into the rathole. With the kelly assembly in the rathole, the crew unhook the swivel bail from the hook, this action frees up the elevator. Crew members latch the elevator around the joint of pipe hanging in the rotary table opening. The driller, using the hoisting system, then lifts the pipe from the hole. Usually, the driller lifts pipe until the third joint clears the rotary table opening. The floor hands then set the slips around the top of the fourth joint. Using the tongs and a spinning wrench, the crew breaks out the three-joint stand from the drill string and sets it back in the mast. Meanwhile, up on the mast, the derrick man handles the upper end of the three-joint stand. He places the top of the stand into a fingerboard, a series of projections near the derrick man’s work platform called the monkey-board. The driller, rotary helpers and derrick man repeat the process until all the drill string is out of the hole.

Tripping with Kelly
Here, the crew is tripping pipe back into the hole. The floor-hands, derrick man and the driller work together to get the drill string back into the hole. Tripping in is pretty much the opposite of tripping out. The driller sends the elevator up to the monkey-board, where the derrick man latches the elevator around the top of the stand. The driller then picks up the stand a little, and the rotary helper guides the lower end over to the string hanging in the rotary table opening. They stab the stand, using the spinning wrench to spin up the stand and make it up to final tightness with the tongs. The crew repeats this process until all the string is back in the hole.

Tripping with Top Drive, 1
When tripping with a top drive, crew members use the drive’s elevator as much as they use a conventional elevator when tripping with a kelly & rotary table rig. With a top drive, the driller can position the links & elevator close to the derrick man on the monkey-board. The driller moves the links & elevator by actuating the remote-controlled link-tilt mechanism on the top drive. Moving the links & elevator makes it easy for the derrick man to latch & unlatch the elevator around the drill pipe stand’s top tool joint.

Tripping with a Top Drive, 2
The drilling crew can also position the elevator in any direction by unlocking the rotation lock and rotating the pipe handler assembly. Being able to position the pipe handler assembly in any direction enables the derrick man and rotary helpers to position the elevator where they need it to make a latch. The elevator returns to its original position when rotated by the drill string.

Tripping with a Top Drive, 3
One advantage of a top drive over a conventional kelly system is its ability to ream or back ream at any position in the mast while tripping. The driller can rotate and move the string up & down through tight section of hole. These actions can ream out the tight section of hole.

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SLIPS & ELEVATOR SYSTEM
Slips
Crew members use wedge-shaped gripping devices called slips to suspend the drill string in the hole. They fit it around the top joint of pipe and wedge in the taper of the rotary table’s opening. Slips have seriated inserts or dies. The inserts grip the outside diameter of the suspended tubular. To set the slips, crew members place them around the pipe. The driller then slowly lowers the pipe until the slips can take up the load. The seriated inserts or dies in the slips firmly hold the pipe. To remove the slips, crew members grasp the slips’ handles. And as the driller picks up the pipe, they lift them out of the rotary table opening and set them aside.

Safety Clamp on Drill Collar
When using drill collars and other tubulars that don not have an elevator shoulder, crew members install a safety clamp above the drill collar slips. If the gripping elements on the drill collar slips failed, the drill collar will slide down. Before the collars could slide all of the way out of the slips, however, the safety clamp would hold the collars against the top of the slips.

Slips & Spiders
Crew members use several types of slips and spiders. A spider, like slips, suspends pipe in the hole, but spiders do not fit inside the rotary table’s opening. Instead, they rest on top of it. Spiders are used instead of slips when the rotary table’s bushing size is not compatible with the tubulars being run. Here you can see Drill Pipe Rotary Slips, Drill Collar Slips, Drill Pipe Coil-Spring Power Slips and Air-Powered Tubing Spider and a 750-ton Air-Controlled Casing Spider. Crew members use each one to hold the corresponding drill pipe, drill collars, casing or tubing. Power slips are powered by a heavy duty, high strength coiled spring or by air. Instead of manually placing air-powered slips in the master bushing, crew members or the driller operate them by remote control.

Elevator
Crew members latch the elevator around the top of pipe joint in the drill string. Once latched, the driller can raise and lower pipe in and out of the hole. Crew members attach the elevator to the hook with 2 forged high grade steel rods called links or bails. One end of the links fits into the link ears on the hook, link locking arms secure the links into the ears. Crew members then attach the elevator to the other end of the links. Most elevators are hinged. Crew members open and close them by operating the latch with two handles on each side. Notice that this elevator has a tapered seat. This taper matches the taper on a tool joint of a length of drill pipe. When properly latched, the tool joint taper rests in the elevator taper and makes a firm, positive grip without damaging the drill pipe.

Lifting Sub
On drill string members that do not have an elevator shoulder, crew members make up a lifting sub into the end of the joint. For instance, this drill collar does not have a shoulder, it is slick. So the crew made up the lifting sub. They latch the elevator onto the taper on the lifting sub to raise or lower drill collars into and out of the hole.

Elevator on Top Drive
On a top drive, the links holding the elevator have an air-operated or pneumatic tilt mechanism. The driller activates the tilt mechanism when the pipe is being pulled from the hole. When the top of the drill string reaches the derrick man’s position at the monkey board, the driller can tilt the top of the stand of the pipe toward the derrick man. The derrick man can then unlatch the elevator and set the stand back in the finger board. The finger board is a rack that supports the top of the stands of pipe being stacked in the mast or derrick.

[TOOL BOX]: It’s time for a quick question: Which one of these tubulars would require a safety clamp? Click on the correct one and then press the “accept” button.

SPINNING & TORQUING DEVICES

Tongs
Tongs are large wrenches that crew members use to make up and break out pipe. The crew uses two sets of tongs to make up & break out pipe. One set is the lead tongs. The lead tongs apply torque to tighten or loosen the connection. The other set is the back up tongs. The back up tongs keep the lower joint of pipe from turning as the lead tongs apply torque to the upper joint.

[TOOL BOX]:
Just what is torque, well torque is a twisting force. Here force is applied in a straight line. Force applied in a straight line is not torque. Torque is force applied in a turning or twisting motion. Here is a top view of a tong arm. We can calculate the torque or the twisting force that the tong arm is putting on the pipe by multiplying the length of the tong arm by the amount of line-pull in pounds or kilograms applied to it. In this case, the tong arm is 4.2 ft or 1.3m long and 2000 lbs or 900 kg of line-pull is applied to it. Click on the tong arm to rotate it. With this length of arm and this amount of line-pull, the tong applies 8400 ft-lbs or 1170 kg-m of torque to the pipe. That’s 4.2 times 2000 equals 8400 and 1.3 times 900 equals 1170. To increase the torque, you can either apply more pounds or kilograms of pull or you can apply the same amount of the line-pull but use a longer tong arm. For example, here the tong arm is 5 ft or 1.5 m long. The line-pull is, however, the same 2000 lbs or 900 kg. Click on the tong arm to see how much torque the longer arm gives. It’s 10000 ft-lbs or 1350 kg-m of torque with a 5 ft (or 1.5m) tong arm. Five times 2000 equals 10000 and 1.5 times 900 equals 1350. So increase of the length of the tong arm or the line-pull increases the torque.

Makeup Cathead
Crew members use the tongs in conjunction with special catheads or winches on the drawworks. When making up drill pipe, the driller actuates the make up cathead on the drawworks. The cathead takes in the tong pull line, a chain in this case, and exerts a strong pull on the tong arm. This pull causes the lead tongs to apply torque to the joint to make it tight.

Breakout Cathead
When breaking out pipe, crew members use the break out cathead on the drawworks. The break out cathead takes in the tong pull line and exerts a strong force on the tong arm. This force breaks out the pipe connection.

Hydraulic Cathead
This is a hydraulic cathead. It’s an auxiliary torquing device. It helps crew members break out and make up very large drill collars. Very large collars require a lot of make up torque so much in fact that the break out cathead’s pulling force may not be strong enough. One solution is to use a hydraulic cathead with rig tongs. The hydraulic cathead includes a hydraulic cylinder housing and a wire assembly. The hydraulic cathead is controlled remotely by the driller from his position on the rig floor. This device produces a safe, powerful, and steady tong line pull to break high torque connections.

Power Tongs
Manufacturers make many types and sizes of power casing & tubing tongs. Crew members use them to connect casing and tubing couplings. Power tongs allow fast and uniform makeup & break out of connections. The make up torque can be preset by adjusting a built-in pressure-relief valve.

Spinning Wrench
Accompanying a rig’s regular tongs is the spinning wrench or pipe spinner. Crew members use a spinning wrench to spin up or spin out pipe connections. For example, once a connection is lubricated and stabbed, they place the spinning wrench on the upper joint and activate the wrench. Rollers engage the pipe and turn it rapidly until shoulder meet shoulder. Then the crew latches the regular tongs to make up the joint to final tightness. They can also reverse the direction of the spinning wrench to spin out a joint that it loosens with the regular tongs.

Kelly Spinner
To spin up or spin out the Kelly, most rigs have a Kelly spinner. The Kelly spinner is hydraulically or pneumatically operated. When the driller activates it, the Kelly spinner rapidly spins up or spins out the Kelly from a joint of drill pipe. Crew members attach it to the Kelly below the swivel.

Iron Roughneck
Some rigs have this vertical pipe handling device. The manufacturer calls it an Iron Roughneck. It combines the lead tongs and back up tongs into a single package. The built-in tongs are hydraulically powered, self-contain torque wrenches. They allow the crew to make up and break out joints without using catheads on the drawworks. An Iron Roughneck mounts on the rig floor and rolls into place on tracks. It reduces the labor involved in making up and breaking out pipe. However, crew members have to maintain it carefully to ensure proper operation.

PIPE TRANSFER
Pipe Racking System
Some rigs working in rough seas or harsh environments use automated pipe racking system. The rig owner mounts the racking system on the rig floor and to the mast. The device racks pipe stands in the mast’s fingerboard. The operator controls the pipe racker from a remote station and views the operation from a camera located directly above the fingerboard. The pipe racking system works in conjunction with the Iron Roughneck. Another type of pipe racking system found on drill ships racks the drill pipe stands in horizontal racks outside the mast or derrick.

Rathole
Crew members place the Kelly assembly in the rathole when they’re ready to make a trip. The rathole is made of large diameter pipe that extends below the rig floor. The rathole also protrudes above the rig floor to make it easily accessible.

Mousehole
The mouse hole is a length of large diameter pipe that extends below the rig floor. The crew places a joint of drill pipe in the mousehole in preparation for adding it to the drill string.
[TOOL BOX]: Drag each label to its proper location by the mousehole and the rathole, then, press the “accept” button.

Air Hoist
Crew members use an air hoist to move pipe and other drilling equipment around the rig floor. An air hoist is an air-powered winch that contains a reel of wire rope. When a crew member actuates the hoist, it takes in rope to lift a piece of equipment. It also has a wire rope guide that the crew member uses to keep the line from winding unevenly on the reel. Usually rigs have several air hoists placed around the rig floor.

Pipe Transfer System
Some rigs use automatic pipe transfer system to pick up and lay down tubulars. The pipe transfer system also moves tubulars onto the pipe deck. The automatic pick-up and lay-down system (PLS) hoists tubulars from the V-Door position to a vertical position. The PLS consists of the Guide Rail Assembly, Hydraulic Lift Arm with slue capacity, Carriage, Winch and control console. The system can pick up or lay down drill pipe, drill collars or casing joints weighing up to 7000 lbs (over 3000kg) and up to 20 inches (or 500 mm) in diameter. The Pipe Deck Machine (or PDM) has a hydraulically controlled mechanical arm. This arm moves tubulars between the pipe rack on deck and the drill floor. The PDM picks up the tubular from the pipe rack, moves perpendicularly on a floor track, and then lowers the tubular to a conveyer. The conveyer carries the pipe up to the V-Door. There, the PLS picks up the tubular and moves it to the elevator for hoisting. Pipe transfer systems are used on jack-ups, semi-submersible, platform and land rigs.

CONTROLS FOR EQUIPMENT
Driller’s Console
The driller controls the rig’s operations from this position at a console. The console is usually on the rig floor, either in the open next to the drawworks or on the latest rigs in a control house on the floor.

Weight Indicator, Gauges, Controls
One important gauge on the instrument panel is the weight indicator. It tells the driller the weight on the bit and the hook load. The hook load is the weight that is suspended from the traveling block and hook. Weight on bit is the portion of the bottom hole assembly weight acting on the bit. Several gauges show the driller pump pressure, pump rate, rotary speed, rotary torque and tong line torque. The driller’s control panel allows the driller to operate the rotating, hoisting and mud pump equipment on the rig.

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VOLUME SEVEN PIPE HANDLING EQUIPMENT
PIPE HANDLING
Overview
The rig crew needs pipe handling equipment for several reasons. One is to make a connection, to add a joint of pipe as the hole deepens; another is to trip the pipe, to take the pipe out and put it back in the hole, so they can change out bit, put a new bottom hole assembly and drill string or perform any other action that requires the drill string’s removal from the hole. Crew members can make connections either by using a kelly & rotary table system or a top drive unit. Handling pipe, tripping it in and out of the hole, connecting joints together, and moving it around the rig floor requires a lot of equipment. Included in this equipment are the elevator, slips, tongs, power tongs, spinning wrenches, catheads, kelly spinner, Iron Roughneck, rathole, mousehole and air hoist. Much of this equipment is controlled at the driller’s console. Transferring pipe from the deck to the rig floor may also involve special handling equipment.
[TOOL BOX]: Here is a little exercise to help you learn the names of all this equipment. When you’re given the name of a component, click on it with your mouse. If you don’t get it the first time, keep trying until you do.

PIPE HANDLING OPERATION

Making a Connection with Kelly
Notice that the kelly is drilled down, that is the rig can drill no deeper without adding a joint of pipe. Here’s the sequence to make a connection with the kelly and rotary table system. The driller picks up the kelly with the hoisting system and the floor crew sets the slips to suspend the drill string in the hole. Using large wrenches, called tongs, the crew loosens or breaks out the kelly from the drill string. They latch one set of tongs called the back up tongs around the drill pipe to keep the pipe from turning when they apply break out torque with the second set of tongs, called the lead tongs.
The driller actuates the break out cathead, which is an automatic winch on the drawworks. The break out cathead pulls a line attached to the lead tongs and loosens the connection. With the connection loosened, the driller spins put the drill pipe from the kelly, usually by slowly turning the rotary table. The back up tongs latched onto the kelly saver sub, keeps the kelly from turning as the pipe spins out. The crew then moves the kelly over to the new joint of pipe placed in the mousehole, a lined opening in the rig floor that holds the joint to be added. They stab the kelly into the new joint. They latch the back up tongs around the tool joint of the pipe joint in the mousehole. The back up tongs keep the joint from turning as the driller spins up the kelly into the joint, using the kelly spinner. The kelly spinner is a pneumatic or hydraulic device mounted near the top of the kelly. To make up the kelly onto the drill pipe to final tightness, the crew latches the lead tongs around the kelly while holding the back up tongs on the pipe’s tool joint box. The driller then actuates the make up cathead on the drawworks. The make up cathead pulls a chain attached to the lead tongs and tightens the kelly onto the drill pipe joint. The driller, using the hoisting system, picks up the kelly and new drill pipe joint out of the mousehole, and the crew guides it to the drill pipe joint, hanging in the rotary table. The crew stabs the new joint into the suspended joint, and the driller actuates the kelly spinner to spin up the new joint.

[TOOL BOX]: Click on the play button to see a video of the kelly being made up.

Once bond up, the crew latches the back up & lead tongs around the joints to make them up to final tightness. With the joints made up, the driller picks up the kelly and drill string. The crew pulls the slips, and the driller lowers the kelly and meets the kelly drive bushing with the master bushing. Drilling then continues.

Making A Connection with a Top Drive
Here is how to make a connection using a top drive. After drilling down the stand, the crew sets the slips. The driller stops circulation, and the crew breaks out the saver sub from the drill pipe using the torque wrench and the top drive’s pipe handler. The driller then uses the top drive’s drilling motor to unscrew the connection. The driller picks up the top drive and a crew member opens the drill pipe elevators to allow it to pass over the box of the pipe, setting in the slips. The driller raises the top drive assembly to the monkey-board. The derrick man latches the triple drill pipe stand in the elevators. The elevators pick up the stand and the floor crew stabs the bottom pin into the drill pipe box in the rotary table.

[TOOL BOX]: Click on the play button to see the joint being stabbed into the drill string.

The driller lowers the top drive to stab the saver sub into the box at the top of the stand. Using the top drive’s drilling motor, the driller spins up both the top connection and the lower connection at the rotary table. The rotary helpers use back up tongs to keep the connection stationary as the pipe spins. Finally, the driller begins circulation, the crew pulls the slips and drilling resumes.

[TOOL BOX]: Here is your chance to supervise the making of a connection, using a top drive. The stand has been drilled down and it’s time to set the slips. The top drive has already been broken up from the drill string and attached to the stand of pipe in the mast. Raise the stand of drill pipe by clicking on the top drive… Good! Now lower the tool joint on to the drill string by moving the top drive downwards with your mouse. Activate the top drive by clicking on it with your mouse. Lift the drill string by moving the top drive upwards. And finally, remove the slips by dragging them out of the insert bowls. Excellent work! Now you are ready to make hole.

Tripping Out with Kelly
Here is a crew on a rig with the kelly & rotary table system tripping pipe out of the hole. That is the rotary helpers, the derrick man and the driller are working together to pull the drill string from the hole. Maybe to change the bit, or something similar.
First, the crew suspends the drill string in the hole with slips. Then they break out the kelly assembly. They swing the assembly over to a lined hole, called the rathole, and the driller lowers the assembly into the rathole. With the kelly assembly in the rathole, the crew unhook the swivel bail from the hook, this action frees up the elevator. Crew members latch the elevator around the joint of pipe hanging in the rotary table opening. The driller, using the hoisting system, then lifts the pipe from the hole. Usually, the driller lifts pipe until the third joint clears the rotary table opening. The floor hands then set the slips around the top of the fourth joint. Using the tongs and a spinning wrench, the crew breaks out the three-joint stand from the drill string and sets it back in the mast. Meanwhile, up on the mast, the derrick man handles the upper end of the three-joint stand. He places the top of the stand into a fingerboard, a series of projections near the derrick man’s work platform called the monkey-board. The driller, rotary helpers and derrick man repeat the process until all the drill string is out of the hole.

Tripping with Kelly
Here, the crew is tripping pipe back into the hole. The floor-hands, derrick man and the driller work together to get the drill string back into the hole. Tripping in is pretty much the opposite of tripping out. The driller sends the elevator up to the monkey-board, where the derrick man latches the elevator around the top of the stand. The driller then picks up the stand a little, and the rotary helper guides the lower end over to the string hanging in the rotary table opening. They stab the stand, using the spinning wrench to spin up the stand and make it up to final tightness with the tongs. The crew repeats this process until all the string is back in the hole.

Tripping with Top Drive, 1
When tripping with a top drive, crew members use the drive’s elevator as much as they use a conventional elevator when tripping with a kelly & rotary table rig. With a top drive, the driller can position the links & elevator close to the derrick man on the monkey-board. The driller moves the links & elevator by actuating the remote-controlled link-tilt mechanism on the top drive. Moving the links & elevator makes it easy for the derrick man to latch & unlatch the elevator around the drill pipe stand’s top tool joint.

Tripping with a Top Drive, 2
The drilling crew can also position the elevator in any direction by unlocking the rotation lock and rotating the pipe handler assembly. Being able to position the pipe handler assembly in any direction enables the derrick man and rotary helpers to position the elevator where they need it to make a latch. The elevator returns to its original position when rotated by the drill string.

Tripping with a Top Drive, 3
One advantage of a top drive over a conventional kelly system is its ability to ream or back ream at any position in the mast while tripping. The driller can rotate and move the string up & down through tight section of hole. These actions can ream out the tight section of hole.

SLIPS & ELEVATOR SYSTEM
Slips
Crew members use wedge-shaped gripping devices called slips to suspend the drill string in the hole. They fit it around the top joint of pipe and wedge in the taper of the rotary table’s opening. Slips have seriated inserts or dies. The inserts grip the outside diameter of the suspended tubular. To set the slips, crew members place them around the pipe. The driller then slowly lowers the pipe until the slips can take up the load. The seriated inserts or dies in the slips firmly hold the pipe. To remove the slips, crew members grasp the slips’ handles. And as the driller picks up the pipe, they lift them out of the rotary table opening and set them aside.

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Safety Clamp on Drill Collar
When using drill collars and other tubulars that don not have an elevator shoulder, crew members install a safety clamp above the drill collar slips. If the gripping elements on the drill collar slips failed, the drill collar will slide down. Before the collars could slide all of the way out of the slips, however, the safety clamp would hold the collars against the top of the slips.

Slips & Spiders
Crew members use several types of slips and spiders. A spider, like slips, suspends pipe in the hole, but spiders do not fit inside the rotary table’s opening. Instead, they rest on top of it. Spiders are used instead of slips when the rotary table’s bushing size is not compatible with the tubulars being run. Here you can see Drill Pipe Rotary Slips, Drill Collar Slips, Drill Pipe Coil-Spring Power Slips and Air-Powered Tubing Spider and a 750-ton Air-Controlled Casing Spider. Crew members use each one to hold the corresponding drill pipe, drill collars, casing or tubing. Power slips are powered by a heavy duty, high strength coiled spring or by air. Instead of manually placing air-powered slips in the master bushing, crew members or the driller operate them by remote control.

Elevator
Crew members latch the elevator around the top of pipe joint in the drill string. Once latched, the driller can raise and lower pipe in and out of the hole. Crew members attach the elevator to the hook with 2 forged high grade steel rods called links or bails. One end of the links fits into the link ears on the hook, link locking arms secure the links into the ears. Crew members then attach the elevator to the other end of the links. Most elevators are hinged. Crew members open and close them by operating the latch with two handles on each side. Notice that this elevator has a tapered seat. This taper matches the taper on a tool joint of a length of drill pipe. When properly latched, the tool joint taper rests in the elevator taper and makes a firm, positive grip without damaging the drill pipe.

Lifting Sub
On drill string members that do not have an elevator shoulder, crew members make up a lifting sub into the end of the joint. For instance, this drill collar does not have a shoulder, it is slick. So the crew made up the lifting sub. They latch the elevator onto the taper on the lifting sub to raise or lower drill collars into and out of the hole.

Elevator on Top Drive
On a top drive, the links holding the elevator have an air-operated or pneumatic tilt mechanism. The driller activates the tilt mechanism when the pipe is being pulled from the hole. When the top of the drill string reaches the derrick man’s position at the monkey board, the driller can tilt the top of the stand of the pipe toward the derrick man. The derrick man can then unlatch the elevator and set the stand back in the finger board. The finger board is a rack that supports the top of the stands of pipe being stacked in the mast or derrick.

[TOOL BOX]: It’s time for a quick question: Which one of these tubulars would require a safety clamp? Click on the correct one and then press the “accept” button.

SPINNING & TORQUING DEVICES

Tongs
Tongs are large wrenches that crew members use to make up and break out pipe. The crew uses two sets of tongs to make up & break out pipe. One set is the lead tongs. The lead tongs apply torque to tighten or loosen the connection. The other set is the back up tongs. The back up tongs keep the lower joint of pipe from turning as the lead tongs apply torque to the upper joint.

[TOOL BOX]:
Just what is torque, well torque is a twisting force. Here force is applied in a straight line. Force applied in a straight line is not torque. Torque is force applied in a turning or twisting motion. Here is a top view of a tong arm. We can calculate the torque or the twisting force that the tong arm is putting on the pipe by multiplying the length of the tong arm by the amount of line-pull in pounds or kilograms applied to it. In this case, the tong arm is 4.2 ft or 1.3m long and 2000 lbs or 900 kg of line-pull is applied to it. Click on the tong arm to rotate it. With this length of arm and this amount of line-pull, the tong applies 8400 ft-lbs or 1170 kg-m of torque to the pipe. That’s 4.2 times 2000 equals 8400 and 1.3 times 900 equals 1170. To increase the torque, you can either apply more pounds or kilograms of pull or you can apply the same amount of the line-pull but use a longer tong arm. For example, here the tong arm is 5 ft or 1.5 m long. The line-pull is, however, the same 2000 lbs or 900 kg. Click on the tong arm to see how much torque the longer arm gives. It’s 10000 ft-lbs or 1350 kg-m of torque with a 5 ft (or 1.5m) tong arm. Five times 2000 equals 10000 and 1.5 times 900 equals 1350. So increase of the length of the tong arm or the line-pull increases the torque.

Makeup Cathead
Crew members use the tongs in conjunction with special catheads or winches on the drawworks. When making up drill pipe, the driller actuates the make up cathead on the drawworks. The cathead takes in the tong pull line, a chain in this case, and exerts a strong pull on the tong arm. This pull causes the lead tongs to apply torque to the joint to make it tight.

Breakout Cathead
When breaking out pipe, crew members use the break out cathead on the drawworks. The break out cathead takes in the tong pull line and exerts a strong force on the tong arm. This force breaks out the pipe connection.

Hydraulic Cathead
This is a hydraulic cathead. It’s an auxiliary torquing device. It helps crew members break out and make up very large drill collars. Very large collars require a lot of make up torque so much in fact that the break out cathead’s pulling force may not be strong enough. One solution is to use a hydraulic cathead with rig tongs. The hydraulic cathead includes a hydraulic cylinder housing and a wire assembly. The hydraulic cathead is controlled remotely by the driller from his position on the rig floor. This device produces a safe, powerful, and steady tong line pull to break high torque connections.

Power Tongs
Manufacturers make many types and sizes of power casing & tubing tongs. Crew members use them to connect casing and tubing couplings. Power tongs allow fast and uniform makeup & break out of connections. The make up torque can be preset by adjusting a built-in pressure-relief valve.

Spinning Wrench
Accompanying a rig’s regular tongs is the spinning wrench or pipe spinner. Crew members use a spinning wrench to spin up or spin out pipe connections. For example, once a connection is lubricated and stabbed, they place the spinning wrench on the upper joint and activate the wrench. Rollers engage the pipe and turn it rapidly until shoulder meet shoulder. Then the crew latches the regular tongs to make up the joint to final tightness. They can also reverse the direction of the spinning wrench to spin out a joint that it loosens with the regular tongs.

Kelly Spinner
To spin up or spin out the Kelly, most rigs have a Kelly spinner. The Kelly spinner is hydraulically or pneumatically operated. When the driller activates it, the Kelly spinner rapidly spins up or spins out the Kelly from a joint of drill pipe. Crew members attach it to the Kelly below the swivel.

Iron Roughneck
Some rigs have this vertical pipe handling device. The manufacturer calls it an Iron Roughneck. It combines the lead tongs and back up tongs into a single package. The built-in tongs are hydraulically powered, self-contain torque wrenches. They allow the crew to make up and break out joints without using catheads on the drawworks. An Iron Roughneck mounts on the rig floor and rolls into place on tracks. It reduces the labor involved in making up and breaking out pipe. However, crew members have to maintain it carefully to ensure proper operation.

PIPE TRANSFER
Pipe Racking System
Some rigs working in rough seas or harsh environments use automated pipe racking system. The rig owner mounts the racking system on the rig floor and to the mast. The device racks pipe stands in the mast’s fingerboard. The operator controls the pipe racker from a remote station and views the operation from a camera located directly above the fingerboard. The pipe racking system works in conjunction with the Iron Roughneck. Another type of pipe racking system found on drill ships racks the drill pipe stands in horizontal racks outside the mast or derrick.

Rathole
Crew members place the Kelly assembly in the rathole when they’re ready to make a trip. The rathole is made of large diameter pipe that extends below the rig floor. The rathole also protrudes above the rig floor to make it easily accessible.

Mousehole
The mouse hole is a length of large diameter pipe that extends below the rig floor. The crew places a joint of drill pipe in the mousehole in preparation for adding it to the drill string.
[TOOL BOX]: Drag each label to its proper location by the mousehole and the rathole, then, press the “accept” button.

Air Hoist
Crew members use an air hoist to move pipe and other drilling equipment around the rig floor. An air hoist is an air-powered winch that contains a reel of wire rope. When a crew member actuates the hoist, it takes in rope to lift a piece of equipment. It also has a wire rope guide that the crew member uses to keep the line from winding unevenly on the reel. Usually rigs have several air hoists placed around the rig floor.

Pipe Transfer System
Some rigs use automatic pipe transfer system to pick up and lay down tubulars. The pipe transfer system also moves tubulars onto the pipe deck. The automatic pick-up and lay-down system (PLS) hoists tubulars from the V-Door position to a vertical position. The PLS consists of the Guide Rail Assembly, Hydraulic Lift Arm with slue capacity, Carriage, Winch and control console. The system can pick up or lay down drill pipe, drill collars or casing joints weighing up to 7000 lbs (over 3000kg) and up to 20 inches (or 500 mm) in diameter. The Pipe Deck Machine (or PDM) has a hydraulically controlled mechanical arm. This arm moves tubulars between the pipe rack on deck and the drill floor. The PDM picks up the tubular from the pipe rack, moves perpendicularly on a floor track, and then lowers the tubular to a conveyer. The conveyer carries the pipe up to the V-Door. There, the PLS picks up the tubular and moves it to the elevator for hoisting. Pipe transfer systems are used on jack-ups, semi-submersible, platform and land rigs.

CONTROLS FOR EQUIPMENT
Driller’s Console
The driller controls the rig’s operations from this position at a console. The console is usually on the rig floor, either in the open next to the drawworks or on the latest rigs in a control house on the floor.

Weight Indicator, Gauges, Controls
One important gauge on the instrument panel is the weight indicator. It tells the driller the weight on the bit and the hook load. The hook load is the weight that is suspended from the traveling block and hook. Weight on bit is the portion of the bottom hole assembly weight acting on the bit. Several gauges show the driller pump pressure, pump rate, rotary speed, rotary torque and tong line torque. The driller’s control panel allows the driller to operate the rotating, hoisting and mud pump equipment on the rig.

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VOLUME EIGHT CASING & CEMENTING
CASING & CEMENT
Overview:
Virtually every well drilled requires casing & cement. Casing is steel pipe that the crew puts into the well bore. The casing prevents the hole from caving in and seals off formations. To do its job, though, the casing has to be cemented in place. A cement crew pumps cement down inside the casing and up the annulus. The cement hardens or sets to hold the casing in place.

Casing Specifications
Casing is steel pipe that comes to the rig in individual joints. A casing crew couples the joints together to run them into the well bore. Casing comes in three ranges of lengths. Range one is 16 to 25 ft (or 4.88 – 7.62m) long; range two is 25 – 34 ft (or 7.62-10.36m) long; range three is 34-48 ft (or 10.36–14.63m) long. The length used depends on the well owner’s requirement and the physical requirements of the well. Casing also comes in different grades or strengths. Which strength is used depends on the well’s characteristics.

Running Casing
To run the casing, the crew joins the joints with threaded connections called couplings or collars. Do not confuse casing collars with drill collars. Casing collars are couplings. They use special heavy-duty elevators and large casing slips, called spiders. They make up the casing joints with multi-speed power casing tongs. Power casing tongs not only screw the threaded connections together, but also torque them to the correct amount.

[TOOL BOX]: Which of these is a casing collar? Click on the casing collar with your mouse and then click on the “accept” button.

CASING STRING
Overview
By the time the crew drills the well to final depth, it usually has several strings of casing in it. These strings are called conductor casing, surface casing, intermediate casing and production casing. Notice that the cased well looks something like a telescope pulled out a full length. That is as the crew drills the well deeper, the size of the hole and the size of the casing gets smaller in diameter. Almost or always, the drilling contractor can not begin drilling at the surface and go all the way to total depth in one step. For one thing, formations near the surface tend to crumble and cave in easily, so conductor casing prevents cave-ins. For another thing, formations near the surface may also hold fresh water that the well can not contaminate. So surface casing protects fresh water zones. For still another thing, deep formations are sometimes so-called troublesome formations. That is they can be drilled by adjusting the properties of the drilling mud, but once drilled need to be sealed off to prevent problems in drilling the deeper portion of the well. So intermediate casing seals off troublesome zones. Sometimes deep wells require more than one intermediate casing string. Finally, once the producing zone is drilled, it needs to be protected and sealed. So production casing isolates the producing zone.

[TOOL BOX]: Here are all of the casing strings unlabeled. To the right you’ll see all of the labels. Using your mouse, drag each label to the proper place on the diagram. When you’ve finished, click on the “accept” button.

PROGRESSIVE CASING STRINGS
Conductor Casing
The first string of casing is the conductor casing. The hole drilled for is pretty big, often as much as 36 inches or more (almost a meter in diameter). The conductor hole has to start up pretty big because as drilling goes on, the hole’s diameter decreases. In some cases, the rig will hammer the conductor casing in place if the ground near the surface is really soft. If the conductor hole is drilled, the casing is cemented in it. Using a bit whose diameter is small enough to easily go inside the conductor casing, the rig drills the hole below the conductor to a prescribed depth.

Surface Casing
The diameter of the surface hole can still be relatively large, say 17 inches (over 400 mm or even more). The surface hole’s depth is usually set by Regulatory Agencies. They require that the surface hole be drilled through all fresh water zones, and the surface casing be set and cemented to protect the zones from damage by additional drilling operations.
This step could be from hundreds to thousands of ft or meters. Normally crew members nipple up or connect the BOPs to the surface casing at the well head. So this casing must be strong enough to support the BOP stack. In addition, it has to withstand the gas or fluid pressures the well may encounter. Surface casing also has to be strong enough to support the additional casing strings hanging inside of it.

Intermediate Casing Strings
To drill the intermediate hole, the operator chooses a still smaller in diameter bit which easily fits inside the surface casing. A bit of about 12 inches (or 300 mm) in diameter is one example of the size. Intermediate casing is also cemented in the place to seal off troublesome formations like lost circulation zones or abnormally pressured zones. It is often the longest section of casing in the well. Also the crew connects or nipples up the BOPs to the top of the intermediate casing by using an adapter and casing head or a drilling spool which is stacked on or connected to the top of the surface casing well head. It therefore anchors the BOPs for the drilling comes later. Remember that the crew has to nipple up a stack of BOPs to each string of casing that’s run into the well. First, they nipple up on the surface casing, then on the intermediate casing, and finally on the production casing. To drill to final depth below the intermediate casing, the rig owner selects a bit whose diameter is small enough to fit inside the intermediate casing, say from 8 to 10 inches (or 200-250 mm).

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Safety Clamp on Drill Collar
When using drill collars and other tubulars that don not have an elevator shoulder, crew members install a safety clamp above the drill collar slips. If the gripping elements on the drill collar slips failed, the drill collar will slide down. Before the collars could slide all of the way out of the slips, however, the safety clamp would hold the collars against the top of the slips.

Slips & Spiders
Crew members use several types of slips and spiders. A spider, like slips, suspends pipe in the hole, but spiders do not fit inside the rotary table’s opening. Instead, they rest on top of it. Spiders are used instead of slips when the rotary table’s bushing size is not compatible with the tubulars being run. Here you can see Drill Pipe Rotary Slips, Drill Collar Slips, Drill Pipe Coil-Spring Power Slips and Air-Powered Tubing Spider and a 750-ton Air-Controlled Casing Spider. Crew members use each one to hold the corresponding drill pipe, drill collars, casing or tubing. Power slips are powered by a heavy duty, high strength coiled spring or by air. Instead of manually placing air-powered slips in the master bushing, crew members or the driller operate them by remote control.

Elevator
Crew members latch the elevator around the top of pipe joint in the drill string. Once latched, the driller can raise and lower pipe in and out of the hole. Crew members attach the elevator to the hook with 2 forged high grade steel rods called links or bails. One end of the links fits into the link ears on the hook, link locking arms secure the links into the ears. Crew members then attach the elevator to the other end of the links. Most elevators are hinged. Crew members open and close them by operating the latch with two handles on each side. Notice that this elevator has a tapered seat. This taper matches the taper on a tool joint of a length of drill pipe. When properly latched, the tool joint taper rests in the elevator taper and makes a firm, positive grip without damaging the drill pipe.

Lifting Sub
On drill string members that do not have an elevator shoulder, crew members make up a lifting sub into the end of the joint. For instance, this drill collar does not have a shoulder, it is slick. So the crew made up the lifting sub. They latch the elevator onto the taper on the lifting sub to raise or lower drill collars into and out of the hole.

Elevator on Top Drive
On a top drive, the links holding the elevator have an air-operated or pneumatic tilt mechanism. The driller activates the tilt mechanism when the pipe is being pulled from the hole. When the top of the drill string reaches the derrick man’s position at the monkey board, the driller can tilt the top of the stand of the pipe toward the derrick man. The derrick man can then unlatch the elevator and set the stand back in the finger board. The finger board is a rack that supports the top of the stands of pipe being stacked in the mast or derrick.

[TOOL BOX]: It’s time for a quick question: Which one of these tubulars would require a safety clamp? Click on the correct one and then press the “accept” button.

SPINNING & TORQUING DEVICES

Tongs
Tongs are large wrenches that crew members use to make up and break out pipe. The crew uses two sets of tongs to make up & break out pipe. One set is the lead tongs. The lead tongs apply torque to tighten or loosen the connection. The other set is the back up tongs. The back up tongs keep the lower joint of pipe from turning as the lead tongs apply torque to the upper joint.

[TOOL BOX]:
Just what is torque, well torque is a twisting force. Here force is applied in a straight line. Force applied in a straight line is not torque. Torque is force applied in a turning or twisting motion. Here is a top view of a tong arm. We can calculate the torque or the twisting force that the tong arm is putting on the pipe by multiplying the length of the tong arm by the amount of line-pull in pounds or kilograms applied to it. In this case, the tong arm is 4.2 ft or 1.3m long and 2000 lbs or 900 kg of line-pull is applied to it. Click on the tong arm to rotate it. With this length of arm and this amount of line-pull, the tong applies 8400 ft-lbs or 1170 kg-m of torque to the pipe. That’s 4.2 times 2000 equals 8400 and 1.3 times 900 equals 1170. To increase the torque, you can either apply more pounds or kilograms of pull or you can apply the same amount of the line-pull but use a longer tong arm. For example, here the tong arm is 5 ft or 1.5 m long. The line-pull is, however, the same 2000 lbs or 900 kg. Click on the tong arm to see how much torque the longer arm gives. It’s 10000 ft-lbs or 1350 kg-m of torque with a 5 ft (or 1.5m) tong arm. Five times 2000 equals 10000 and 1.5 times 900 equals 1350. So increase of the length of the tong arm or the line-pull increases the torque.

Makeup Cathead
Crew members use the tongs in conjunction with special catheads or winches on the drawworks. When making up drill pipe, the driller actuates the make up cathead on the drawworks. The cathead takes in the tong pull line, a chain in this case, and exerts a strong pull on the tong arm. This pull causes the lead tongs to apply torque to the joint to make it tight.

Breakout Cathead
When breaking out pipe, crew members use the break out cathead on the drawworks. The break out cathead takes in the tong pull line and exerts a strong force on the tong arm. This force breaks out the pipe connection.

Hydraulic Cathead
This is a hydraulic cathead. It’s an auxiliary torquing device. It helps crew members break out and make up very large drill collars. Very large collars require a lot of make up torque so much in fact that the break out cathead’s pulling force may not be strong enough. One solution is to use a hydraulic cathead with rig tongs. The hydraulic cathead includes a hydraulic cylinder housing and a wire assembly. The hydraulic cathead is controlled remotely by the driller from his position on the rig floor. This device produces a safe, powerful, and steady tong line pull to break high torque connections.

Power Tongs
Manufacturers make many types and sizes of power casing & tubing tongs. Crew members use them to connect casing and tubing couplings. Power tongs allow fast and uniform makeup & break out of connections. The make up torque can be preset by adjusting a built-in pressure-relief valve.

Spinning Wrench
Accompanying a rig’s regular tongs is the spinning wrench or pipe spinner. Crew members use a spinning wrench to spin up or spin out pipe connections. For example, once a connection is lubricated and stabbed, they place the spinning wrench on the upper joint and activate the wrench. Rollers engage the pipe and turn it rapidly until shoulder meet shoulder. Then the crew latches the regular tongs to make up the joint to final tightness. They can also reverse the direction of the spinning wrench to spin out a joint that it loosens with the regular tongs.

Kelly Spinner
To spin up or spin out the Kelly, most rigs have a Kelly spinner. The Kelly spinner is hydraulically or pneumatically operated. When the driller activates it, the Kelly spinner rapidly spins up or spins out the Kelly from a joint of drill pipe. Crew members attach it to the Kelly below the swivel.

Iron Roughneck
Some rigs have this vertical pipe handling device. The manufacturer calls it an Iron Roughneck. It combines the lead tongs and back up tongs into a single package. The built-in tongs are hydraulically powered, self-contain torque wrenches. They allow the crew to make up and break out joints without using catheads on the drawworks. An Iron Roughneck mounts on the rig floor and rolls into place on tracks. It reduces the labor involved in making up and breaking out pipe. However, crew members have to maintain it carefully to ensure proper operation.

PIPE TRANSFER
Pipe Racking System
Some rigs working in rough seas or harsh environments use automated pipe racking system. The rig owner mounts the racking system on the rig floor and to the mast. The device racks pipe stands in the mast’s fingerboard. The operator controls the pipe racker from a remote station and views the operation from a camera located directly above the fingerboard. The pipe racking system works in conjunction with the Iron Roughneck. Another type of pipe racking system found on drill ships racks the drill pipe stands in horizontal racks outside the mast or derrick.

Rathole
Crew members place the Kelly assembly in the rathole when they’re ready to make a trip. The rathole is made of large diameter pipe that extends below the rig floor. The rathole also protrudes above the rig floor to make it easily accessible.

Mousehole
The mouse hole is a length of large diameter pipe that extends below the rig floor. The crew places a joint of drill pipe in the mousehole in preparation for adding it to the drill string.
[TOOL BOX]: Drag each label to its proper location by the mousehole and the rathole, then, press the “accept” button.

Air Hoist
Crew members use an air hoist to move pipe and other drilling equipment around the rig floor. An air hoist is an air-powered winch that contains a reel of wire rope. When a crew member actuates the hoist, it takes in rope to lift a piece of equipment. It also has a wire rope guide that the crew member uses to keep the line from winding unevenly on the reel. Usually rigs have several air hoists placed around the rig floor.

Pipe Transfer System
Some rigs use automatic pipe transfer system to pick up and lay down tubulars. The pipe transfer system also moves tubulars onto the pipe deck. The automatic pick-up and lay-down system (PLS) hoists tubulars from the V-Door position to a vertical position. The PLS consists of the Guide Rail Assembly, Hydraulic Lift Arm with slue capacity, Carriage, Winch and control console. The system can pick up or lay down drill pipe, drill collars or casing joints weighing up to 7000 lbs (over 3000kg) and up to 20 inches (or 500 mm) in diameter. The Pipe Deck Machine (or PDM) has a hydraulically controlled mechanical arm. This arm moves tubulars between the pipe rack on deck and the drill floor. The PDM picks up the tubular from the pipe rack, moves perpendicularly on a floor track, and then lowers the tubular to a conveyer. The conveyer carries the pipe up to the V-Door. There, the PLS picks up the tubular and moves it to the elevator for hoisting. Pipe transfer systems are used on jack-ups, semi-submersible, platform and land rigs.

CONTROLS FOR EQUIPMENT
Driller’s Console
The driller controls the rig’s operations from this position at a console. The console is usually on the rig floor, either in the open next to the drawworks or on the latest rigs in a control house on the floor.

Weight Indicator, Gauges, Controls
One important gauge on the instrument panel is the weight indicator. It tells the driller the weight on the bit and the hook load. The hook load is the weight that is suspended from the traveling block and hook. Weight on bit is the portion of the bottom hole assembly weight acting on the bit. Several gauges show the driller pump pressure, pump rate, rotary speed, rotary torque and tong line torque. The driller’s control panel allows the driller to operate the rotating, hoisting and mud pump equipment on the rig.

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Production Casing Strings
This part of a hole penetrates the producing zone. When cemented in place, production casing seals off the production zone and readies it for production. Production casing also houses and protects the tubing and other equipment used to produce the well. The operator usually perforates, puts holes in this casing when the well is complete, already for work to begin. Well completion is the term describing the activities and methods of preparing the well for production of oil or gas. Oil and gas flow into the well through the perforations.

Liner Strings
Sometimes well owners run liners instead of casing into the well. A liner is a shorten string of casing used to case the smaller open hole section below an existing casing string in the hole. It’s just like casing, except that a liner does not run all the way to the surface. Instead, the casing crew hangs it from the bottom of a previously run casing or liner string using a special piece of equipment called a liner hanger. In this case, there is an intermediate liner and a production liner. Using liners saves money since they do not extend to the surface.

[TOOL BOX]: For each type of casing you see, you’ll be given the diameter. Using your mouse, click on the correct name of the casing shown.

CASING ACCESSORIES
Overview:
Because the crew will cement the casing string in place, they also have to install some special devices on this string, which come to play during the cementing operation.

Guide Shoe
The guide shoe is a heavy steel and concrete fitting that the crew makes up on the end of the first casing joint to go in the hole. It guides the casing pass the rough spots and ledges on the well bore. It also has an opening in the end. Drilling mud enters this opening when the crew runs the casing into the well bore. Later, cement will come out of this opening on its way into the annulus.

Float Collar & Shoe
Usually, the crew installs a float collar in the second or the third casing joint run into the well bore. Or sometimes they install a float shoe. Whether a float shoe or a float collar is used, each has a one-way valve in it. Fluids can flow downwards through the valve, but can not flow upward pass the valve. The float collar or float shoe keeps drilling mud from entering the casing string as the crew runs it into the hole.
Keeping the casing empty of mud allows the casing to partially float in the mud. That is, in the annulus, just as a hollow steel boat floats on water. Letting the casing float cuts down on stress and fatigue on the hoisting equipment. But the crew can not keep the casing totally empty of mud. If they did, the hydrostatic pressure of the mud in the annulus could crash the casing. So from time to time, the crew puts mud into the inside of the casing from the surface to offset hydrostatic pressure. The float valve also holds the cemented place once it is displaced into the annulus; otherwise it would u-tube, back into the casing.

Centralizers
On various joints of casing, crew members also install centralizers. Centralizers keep the casing from leaning against the side of the hole. In other words, centralizers keep an opening between the outside wall of the casing and the wall of the hole. Centralizers reduce drag and differential sticking while running the casing. Drag is resistance to motion caused by the casing contacting the well bore. Differential sticking happens when the casing contacts a permeable formation in the well bore. And the pressure in the hole is greater than the pressure in the formation. The higher hole pressure tenses the hole the casing in contact against the area of lower formation pressure. Keeping the casing off the wall off the hole also ensures that cement will surround the outside of the casing and bond it securely to the hole.

[TOOL BOX]: In order for the cement to fill the annulus properly, it is important that the casing string be as centered as possible. Click on the button marked, add centralizers to see the effect of centralizers. Here you see a casing string that has zero percent standoff, this means that it’s up against the side of the well bore. Change the standoff to see how standoff effects cementing. 50 percent: This string has a 50% standoff. As the cement flows up the annulus, it will fill the wider side of the annulus more quickly. This leads to an inadequate cement job; 75 percent: This string has a 75% standoff. 67% standoff is the minimal acceptable standoff. So it’s 75%, this cement is adequate. However, it’s not optimal; 100 percent: Here the string has a 100% standoff. That means it is perfectly centered. At 100% standoff, the cement flows evenly on both sides of the casing, leading to a good cement job.

Scratcher
Another device that helps ensure a good bond of cement to the hole is a scratcher. Depending on the well bore’s characteristics, crew members install several on the casing string. Just before they pump the cement into the casing in hole, they rotate the casing string. When move it up & down, that is reciprocate it. Depending on the type of scratchers they install. In either case, the scratchers remove wall cake left by the drilling mud during drilling. Removing the wall cake, solid particles in the mud is stick to the wall of the hole, helps the cement bond better to the hole.
[TOOL BOX]: Let’s see what happens when the cement does not bond properly to the hole. Click on the buttons to compare a good cement job to a bad one. GOOD: The cement in this well bore is properly bonded; the production fluids enter the casing through perforations, and flow up the casing to the surface. Fluids and gas from other formations are not allowed into the well. BAD: The cement in this well bore is not properly bonded to the hole. This creates channels that allow the fluids & gases from formations besides the one being produced to enter the annulus. This is undesirable since the well and other formations can be damaged.

CEMENTING
Overview
Here is an overview of casing cemented in a well, called primary cementing, the cement’s main jobs are to completely isolate or totally seal off all the oil, gas and water zones from the well bore, and to bond the casing firmly to the wall of the hole.

Casing Point
Here, the crew has drilled the well to the casing point, the depth at which they’ll set and cement casing.

Conditioning the Hole
The driller circulates drilling mud to clean the hole and make sure the mud is in good condition. Then the crew pulls the drill string out of the hole.

Running the Casing
The next step in primary cementing is for the casing crew to run the casing into the well, one joint at a time. Notice that at the bottom of the casing, the guide shoe and float collar. Also notice the centralizers and scratchers. The guide shoe guides the first joint of casing into the well bore. A valve in the float collar lets the crew float the casing into the well to lessen the load on the rig’s hoisting system. Centralizers keep the casing off the wall of the hole to ensure a good cement job. And scratchers remove wall cake to ensure a good cement bond to the wall of the hole.

Mixing the Cement
The cementing crew next to ready the cementing unit. The cementing unit rapidly mixes water, dry cement, and special additives to the cement to make a liquid cement slurry. A high pressure cement pumping unit moves the slurry down the casing.

Pumping Cement
To get the cement slurry down the casing, the cementing crew makes up a cementing head, also called a plug-retainer, on the top joint of casing suspended in rig’s elevator. The cementing head has an inlet for the cement slurry from the cement pump. Slurry enters the head at the connection on the side. The valves on the head allow the crew to control the point at which the slurry enters the head. From the cementing head, the slurry goes into the casing. The head also holds special plugs called wiper plugs. The wiper plug retainers keep the wiper plugs in head until the crew releases them to allow the plugs to be pumped down the casing. The fluid inlet allows the crew to pump mud, water or special displacement fluid, the fluid that pushes the cement into the annulus. This head holds two wiper plugs, a bottom wiper plug, and a top wiper plug. The bottom plug goes into the casing first. It wipes mud off the inside of the casing and separates the mud from the cement. The top plug follows the last of the cement into the casing. It wipes cement off the inside of the casing and separates cement from the displacement fluid.

[TOOL BOX]: Often the wiper plugs are identified by different colors to avoid confusion. The bottom plug is usually red or orange. It has a diaphragm that breaks when the plug gets to the bottom of the casing string; so that the cement can pass through the plug. The top plug is usually black.

Finishing the Job
Cement pump pressure moves the cement slurry to the cementing head where a crew member releases the bottom wiper plug. Slurry pushes the bottom plug down the casing until it seats in the float collar. When the plug seats, continued pump pressure on the slurry raptures the diaphragm on the bottom of the plug. This allows cement slurry to go out the guide shoe and into the annulus. When the calculated amount of cement slurry has been pumped, a crew member releases the top wiper plug. Displacement fluid forces the top wiper plug down the casing until it seats in the float collar on the top of the bottom plug. Because the top plug is solid, pump pressure rises when the plug seats. A sharp rise in pump pressure signals the pump operator to shut down the pump. The float valve holds the cement in place, not allowing it to u-tube back into the casing once it is displaced into the annulus. The cementing job is complete. Depending on hole conditions and the type of cement used, the cement slurry hardens or sets up firmly generally with 12 to 24 hours.

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VOLUME NINE WELL LOGGING, MUD LOGGING & DRILL STEM TESTING

WELL EVALUATION
Overview
One question that often faces the well owner is “will this well produce oil and gas?” To help answer this question, one or more methods of evaluation are used including: Mud Logging, Well Logging and Drill Stem Testing (or DST). Mud logging involves doing tests on the drilling mud and cuttings circulated out of the hole; well logging is the recording of information about subsurface geologic formations; drill stem testing is a way to test a formation using the drill stem, a special tool & packer assembly installed in the drill stem, records down hole pressures and temperatures and retrieves fluids examples.

MUD LOGGING / TESTING 1
Mud Logging & Testing
As the bit drills, drilling mud lifts cuttings up the hole. The drilling mud also carries traces of any hydrocarbons & other substances the hole may have penetrated. Therefore, catching and analyzing the mud and the cuttings that come to the surface can tell the well owner and geologist a great deal about what’s going on down hole as the bit drills. Analyzing the drilling fluid is called mud logging.

Mud Logging Unit
An overview of a land rig shows the mud logging unit. Offshore, a similar skid-mounted unit houses the mud logging equipment. Both contain sophisticated data acquisition system and equipment for analyzing drilling fluid & cuttings. Here is the inside of a mud logging unit. You can see some of the equipment used to analyze or log mud. This drawing of a mud logging unit shows many items of equipment used to analyze and monitor the drilling process. Not all rigs will have such a set-up and some will even have more sophisticated set-ups.

Rig Monitors
Rig monitors give read-out to the mud logger, a person whose specialty is observing and analyzing mud & cuttings. The rig monitors show the rate of penetration (or ROP), how fast the bit is drilling, weight on the bit (or WOB), total hook load, Kelly or top drive height, rotary speed (or RPM), rotary torque (the twisting force on the drill string), pit volume (the level of mud in the mud tanks), mud weight (in and out of the hole), mud temperature, pump strokes, casing & stand pipe pressure, and other information. Mud loggers can combine rig information with other information from the driller, the wire line operator and area well records to help improve the well’s progress.

Chromatograph
A chromatograph displays the percentages of hydrocarbon gases in the mud returning to the surface. The chromatograph has sensors in the mud return line. These sensors detect such gases as methane, ethane, and propane that maybe in the mud.

Core Plugging Apparatus
The core plugging apparatus takes a small plug out of a core sample. The mud logger can analyze the plug to get an idea of what the larger core sample may contain.

Fluoroscope
A fluoroscope contains an ultra violet lamp. When the mud logger or geologist puts cuttings or plug under the fluoroscope, the cuttings or plug glow or fluoresce if they contain hydrocarbons.

Microscope
A microscope, this unit has two, helps the mud logger or geologist identify the formations. By looking at cuttings or plugs under the microscope, the loggers can note very small rock characteristics, they may also find fossils that help identify the rock.

[TOOL BOX]: A fossil is the remains or impressions of a plant or animal of past geological ages, that’d been preserved in or as rock, because certain kinds of fossils tend to occur in certain kinds of rock. Identifying the fossils helps identify the rock.

Computers
Computers help mud loggers analyze and interpret an important information they gain from mud logging equipment. In some logging units, powerful computers directly read drilling information, process it, and print out detail reports on the status of the well.

Vacuum Oven
Mud loggers use a vacuum oven to dry up formation samples. Then they evaluate the dried samples for further facts about the formations being drilled.