Hi,
I have been working on a problem and having a little difficulty and hope that someone can provide some help. I will post the problem and discuss my issues.
'It is hoped to flow a well at an oil production rate of 400 stbo/d. The reservoir has a P.I of 0.5 stbl/d/psi and the current Pr= 2800 psi. The well is equipped with a 4000 ft of 2.441 inch (ID) tubing and the required Pwh is 160 psi. The producing GLR is 100 scf/stb and 50% water production is expected. Other relevant information:
Pb=3000 psi
Gas Gravity=0.65
Oil API Gravity=35
Water Specific Gravity=1.07
Average Flowing Temperature=150 F
Will the well flow at the desired rate (400 STBO/D)?
- It is my understanding that this is a saturated reservoir. Should I assume that the P.I=0.5 STBL/D/PSI is linear? If this is the case I would solve for the Pwf using Pwf = Pr-q/PI which works out to be 1200 psi.(not even sure if this first step is necessary). From the appropriate gradient curve (800 stbl/d and 50% w/c) I could find my Pwf (found to be 1520 psi) that would be required to flow at this rate and Pwh. Once this is solved I could calculate the STBL/D, which works out to be 640 using the formula q=p.i(pr-pwf). And therefore would not be capable of flowing the desired rate.
- I guess what I am struggling with is I know this is a saturated reservoir and perhaps assuming it's behavior is linear would be incorrect. Typically I would use Vogel's relationship but I'm not sure how I would get qmax since there is no test data given.
- could I calculate qmax assuming AOF (pwf=0 psi) and the use vogel's equation qo = qmax (1-0.2 (Pwf/Pr) - 0.8(Pwf/Pr)^2). and if this value is greater than 800 STBL/D ( with 50% w/c would give us 400 STBO/D) then the well would be capable of flowing the desired rate.
Any help into this problem would be greatly appreciated. Thank you for all your help.
Cheers
Petengineer
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