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.
If i'm given Initial reservoir, bubble point, current reservoir, and flowing bottom hole (as in 26), can you help me understand what to use?
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ReplyDeleteYou need to BP to see it's saturated and thus Vogel applies. After that:
1. Pwf/Pr = 1,100/2,200 = 0.5
2. Vogel Chart: 0.7 = qwf/qmax = 420/qmax so qmax = 600 BPD
3. FE = 600 BPD / 0.7 = 857 BPD.
Check?
Sorry, i think my question was more around how do i know to use bubble point pressure for Pr? If my current reservoir pressure is under BP, know I need to use that as my new res press?
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