Problem 28. Well: Perfs: at 2,630 ft. Reservoir:10 ft thick; k = 40 md; skin = 2. Tbg: 4.5 inch, 12.6 lb/ft. Fluid vis & compressibility 1 cp & 0.0005/psi. PBU wellbore storage time (hr):
(A) 5.5; (B) 18.5; (C) 21.5; (D) 11.5?
Solve using Guidebook 12 WLT 13.
Wellbore V = 2,630 ft (0.0152 bbl/ft) = 40 bbl.
Cs CwbVwb = 0.0005 1/psi(40 bbl) = 0.02 bbl/psi
t (wbs) = [170M(Cs)(e^(0.14*s))]/[kh/u]
t (wbs) = [170M(0.02)(e^(0.14*2))]/[(40*10)/1] = ~11.5 hr.
For number 29, I used 12 WLT 12 to find m, and then rearranged pressure drop using skin for s=delta p/(.869*m) Is that the way to go about it? I'm getting 2.98 though for skin?
ReplyDeleteYou got the right answer skin 3 (A).
DeleteIt's the same problem as on 12 WLT 4; the only trick is the FVF is given as shrinkage factor.
All good?
Yeah, I was just worried that 2.7 was closer to what I got (2.98) than 3.2 was. So many tricks.
DeleteSo the FVF or Bo is just 1/shrinkage? just to be sure.
ReplyDeleteAs a good check, look up "shrinkage factor" and "formation volume factor" in the Hyne Dictionary & time yourself. You should have a good understanding in <30 sec. The reason I include this in the problem is to get people used to doing this very fast in a time-limited situation.
Delete