IPR: 2018 #58

Problem 58: Well: 2,200 psia reservoir produced through a workstring at 50% drawdown produces 600 BOPD & 192 BWPD.

Analysis of the well’s planned tubing predicts bottomhole pressures (psia) of 1386, 1296, 1236, 1196, 1166, 1146, 1136, 1146 at corresponding oil rates of 100, 200, 300, 400, 500, 600, 700, 800 bbl/day. Water production rates are 32% of oil production.

Applying a well-known, easy-to-use three-phase flow model, the fluid production (BFPD) through the new tubing string will be closest to:

7 PRD 1 or HS4 P19. Wiggins is the only well-known 3-phase model. Steps:

1. Calculate water rates 32% of oil rate.
2. Calculate qomax & qwmax (968 qo & 337 qw) using Wiggins from rates (600 qo & 192 qw) at 50% DD.

...Given pwf: 1546, 1386, 1296, 1236, 1196, 1166, 1146, 1136, 1146.
3. Sum qo+qw at pwf (bfpd): 466, 132, 264, 396, 528, 660, 792, 924, 1056 for TBG curve.
4. Calculate Wiggins IPR (oil & water; sum for bfpd): 613, 672, 709, 734, 753, 765, 771, 765.
Crossover is found at 762 bfpd (note underlines at 753 & 765).
On an exam skip for central points & round your answers. It's easy to make an error if you don't have Excel handy...I sure did trying it fast by hand. But that's how you will want to practice; how you practice is how you will test.

Sorry for the delay on this solution; The answer (A) was not an exact answer yet this problem is tough enough I updated it for an exact solution for future users. Note there should be nothing like this level of difficulty on the CBT, since those equations are not in the approved text and could not easily be given in the problem. But a word question could be asked, so reviewing this problem is a good idea.