Vogel: 2018 #55

Problem 55: A saturated 2,200 psi sandstone reservoir has 13 producing wells yielding 18 MBOPD. One of these wells produces 400 BOPD with a flowing bottom hole pressure of 1800 psig; this well has a SSSV at 1,000 ft TVD with a 3-inch ID.

Oil viscosity, the formation volume factor, oil saturation, and permeability are 3.1 cp, 1.2 bbl/STB, 0.77, and 0.82 millidarcies, respectively.

Simulations predict the reservoir pressure will fall 400 psi in 3 years and remain saturated; oil viscosity, FVF, saturation, and permeability should remain roughly the same. The maximum oil rate (STB/day) for this well after 3 years will be closest to: (A) 1010; (B) 1060; (C) 1090; (D) 1120

Guidebook 7 PRD 1. Saturated? Think Vogel.

qo max = qo current/(1-0.2*(pwf/pr)-0.8*(pwf/pr)^2) = STB/day
qo max = 400/(1-0.2*(1800/2200)-0.8*(1800/2200)^2) = 1330 STB/day
qo max future = qo max(pr f/pr p) = 1330/(1800/2200) = 1088 STB/day

Update: this is a "future" well performance problem. First do the Vogel calculation for "current" qo max (using current qo, pf, & pr). Second find the "future" qo max based on future pr. Note this is a simple, linear relationship only if oil fluid properties & permeabilities "remain roughly the same". For more details, see the Guidebook's references on 7 PRD 1. 

Vogel IPR: 2005 #64 (similar)

Vogel IPR problems generally involve: 1) calculating Vogel IPR using the qo/qmax equation (see 7 PRD 1 on how to calculate qmax from a given well test, in this case say, 600 BOPD), 2) calculate qo for a range of FBHP that crossover the TBG curve, and 3) note that the well's natural flow rate is where the IPR & TBG curves cross. That's it.

From the calculated and plotted IPR example below, it's easy to see the roughly 338 psi crossover. For this example, the TBG curve is simply given and the IPR calculated (using as few points as possible, just the crossover area).

For a good explanation of this problem type, see Well Performance by Golan (P29), or Production Optimization by Beggs (P142). Both these resources are excellent (I own both even though they have quite a bit of overlap).

Note that neither of these sources are SPE. Personally, I find the lack of example problems for nodal analysis (or total system analysis) to be a major gap in the SPE Handbook and the SPE Textbook Series. For this reason, I've never spent much time on this problem type. However, I get continual questions about it so I'm showing a detailed similar solution and how to use the Guidebook's applicable section for it. Also, for anyone interested in more explanation the SPE 6th Edition (1991) has an excellent example problem they walk you through as well.

However: Vogel IPR as a "concept" is definitely fair game and is found in HS IV P1-40 (albeit with a lack of example problems or number examples). So understand IPR (including Vogel, Fetkovich, Jones, and Wiggins, who wrote HS IV C1). I'll try and fit an IPR-style problem into the Guidebook Companion 2018 41-80 to help with reviewing this problem type.

IPR Vogel Equation
bopd psia
259 1600
329 1400
392 1200

Given TBG curve 
bopd psia
200 1450
300 1390
400 1350

 

Vogel & Flow Efficiency: 2005 #26 (similar)

Vogel problems often involve flow efficiency (FE). Why? They both need Pwf & Pr.

Example: Say Pwf = 1M and Pr = 2M psi at q = 490 BOPD. What is qmax?
Go to the Vogel table (7 PRD 1) with Pwf/Pr = 0.5; note qo/qmax = 0.7.
So qmax = qo/0.7 = 490/0.7 = 700 BOPD.

But what then if FE is 0.7 and we stimulate to an FE = 1? See 12 WLT 2:

Another way to describe FE: the percentage of well fluid producing at a given drawdown compared to what it would produce with zero skin (FE = 1).

So at FE = 1.7M/0.7 = 1,000 BOPD.