Effect of increase in WC on bottom hole flowing pressure

[amahaminer]

what is the Effect of increase in W/C on bottom hole flowing pressure??

[ELgharib]

U will need more energy to flow the same rate. If the system remain unchanged, the FBHP will increase to produce the same the rate, but the reservoir will not deliver the same rate. then u will find a new equilibruim...=> Higher FBHP and lower rate!

[amahaminer]

yes , but i thought that it would decrease as it would be faced with higher head in tbg (due to water prod.) that would make force in opposite direction & the net effect is reduction.
what do you think????????

[ELgharib]

The VLP (vertical lift performance) is governed by three terms : hydrostatic, Friction and acceleration, the last being negigible.
When you have a high WCT, Hydrostatic term will be the more affected.
You will need more pressure downhole to lift the fluid that has become heavier, keep in mind that the FBHP is the one that bring the fluid to surface.
In fact, it is a kind if optimum you are looking for : Low FBHP to get more fluid from the reservoir (meaning high Drawdown) and high FBHP to bring the fluid to surface.....
As a nutshell, your FBHP will definitely increase...You can the effect of WCT on Flow performance in reference books.

[amahaminer]

El gharib:: Thanks alot for ur interest&answers i agree with u in ((You will need more pressure downhole to lift the fluid that became heavier))
but who would tell the reservoir that i want a production rate of say 600BPD so( mrs: reservoir) kindly increase your bottom hole flowing pressure as W/C now increased .
, i don't understand why would the reservoir increase the bottom hole flowing pressure automatically!!!

could u tell me where exactly to read about this effect

[ELgharib]

You have the choke to regulate the rate, if you are not operating Open hole. If you red my statement, I said the FBHP will increase and the production will decrease at the same time to reach the new equilibrum point where the reservoir furnish enough pressure to lift the fluid to surface. A good book for your reference : Well_Performance__2nd_Ed.__-_M._Golan. if u have a yahoo adress let's tchatch

[amahaminer]

amahaminer@yahoo.com

[amahaminer]

pls if any one has other opinion,share

[halim78]

pls if any one has other opinion,share

My friend,
What Elgharib said is correct, so there is no other opinion to say about this issue.

[vinomarky]

Elggharib is indeed correct, but let me try to restate simply the situation

The reservoir has a static BH pressure at which no flow will occur (ie shutin) - for every 1 psi less of BH pressure, the formation will flow fluids of a rate determined by its PI

When you are flowing naturally, the amount of drawdown you can place in a well is dictated by (a) hydrostatic of the produced fluids (a function of fluid gravities and cuts) , (b) friction (a function of rate and wellbore geometry) and (c) THP imposed (a function of choke settings and surface network limitations)

If you can managed to get a THP of zero (no choke or surface restrictions) and have large bore tubing (negligible friction) then the amount of drawdown available boils down to the difference between the reservoir pressure and the hydrostatic of the produced fluids

In this scenario, if your watercut increases, (assuming you don't have very low API oil that is can be more dense than water) then the hydrostatic will increase, reducing the available drawdown - The BHP will increase and the rate will decrease

[ahmedj9579]

hi every one.
is very simple:
as we know dw>do so if w/c incr then do incre
also; pf = h*d/10 then pf will incre
in other way, q=PI(pr-pf) so if q increase; pf will decrease
in conclusion increase in W/C will increase on bottom hole flowing pressure and decrease of flow q
hope this will help you.