well planning(exploration&development)wells

[ahmed abou zena]

hello every body
to all members i want to know what's the difference between exploration&development wells about well planning .how can i take a decision,make a plane in any one from these type of wells?

thanks alot

[ahmed abou zena]

i need answers, please.

[Yengineer]

In case of an exploratory well, the strata and target zone properties are unknown. It is also unknown, if the well will be successful or not, so it is generally attempted to drill this well as safe as possible with minimum costs.
Therefore, casing safety margins are bigger, additional equipment is employed to detect and calculate formation pore pressure, H2S detection etc.

In a development well, you know what the formation is capable to deliver, the completion/production engineers have a better idea how to complete the well and what size the casing should be. So you know with which bit you have to enter the target zone. Then you start the calculation backwards. Since you also have a better idea of formation you will drill, the fluid properties and casing setting depths can be adjusted accordingly.

[ahmed abou zena]

do you mean i'll drill over balance in exploratory well?

[Yengineer]

Yep!