Behind Pipe Potential & Reserves

[Maratzhan]

Dear Gentlemen,

I receintly started working on a mature field. The reservoir type is sandstone. Multy stack hydraulically sepreated by shales. The number of vertical zones/reservoir pools is approx 40. The reservoir dvelopment strategy is simple - produce/deplete the lowest possible reservoir with the sequential recompletion to the upper zones. Sometimes there are comingled prod cases. Apart of the vertical compartmentalisation, the field is also compartmentalised areally - highly faulted.

The matter is as following: I need to evaluate the behind pipe potential & reserves for the entire field, and for about 150 active wells. I have already prepared the table with the remaining net pays by well / by compartment (vert. areal). I need to integrate the remaining net pays with the current production data by well.

Does anyone have suggestions?

I started working with DCA i.e. identifing the decline rate per well in such a way apply same decline rate for the period after well is worked over and new perforations added. I say DR per well, because in the case of comingled cases there is no data e.g. PLT to allocate the production.

Let us have some brain storming, and see what we can approach.
I will appreciate if you'd reply to my mail directly as I can not access forum at office.

m.nurov@gmail.com

[temr]

Con_prod=MaxDeltaP*CCF/oilvisq
Sum production for all connections

[vinomarky]

By zone(s) what EUR has been produced
What was the net sand thickness
When was it produced
What was the Pi (online well pressure)
How is the Pi for each sand trending with cumulative withdrawals from that unit?

With 150 active wells, there is a reasonable likelihood that you'll see a relationship for the various sands between the EUR produced, the net thickness, the initial pressures and the online date

Extrapolate these relationships for the remaining sands.... easier said than done I know

A very useful tool to help look for relationships between EUR's and data such as sand unit, net pay, PI and online date (creaming curve) is Spotfire. I use it often in my day-to-day activities - think of it like Excel for data mining/analysis - a blank canvas limited only by your imagination - you'll still have to assemble all the input information yourself

With such compartmentalization, depending upon your well costs, there is quite probably additional infill reserves as well - there will likely also be a creaming curve of EUR vs reducing well spacing.

Good luck