The right J to make use of during the Eqs. six and 7 depends on brand new moving bottomhole tension of one’s decide to try section. In case your flowing bottomhole pressure was more than the fresh bubblepoint tension, then your well are experience single-stage circulate standards and you may J hinges on
Immediately after J is decided to the take to conditions, it is regularly assess the whole inflow efficiency curve one another a lot more than and you can below the bubblepoint tension that have Eqs. 7 and you will 8. The fresh new compound IPR is relevant if mediocre reservoir pressure are higher than the new bubblepoint stress.
Three-stage move
Wiggins [9] showed an easy-to-explore IPR for a few-phase move, that’s equivalent in form so you’re able to Vogel’s IPR. It was based on a series of simulation knowledge. They returns results the same as two most other three-stage circulate models [8] [10] in fact it is easier to incorporate. Eqs. eleven and you can twelve allow the generalized about three-stage IPRs to have petroleum and you may water, respectively.
Analogy
Desk step 1 merchandise analysis to own a good multipoint shot into the a promoting oils well-used to show both-phase IPR steps. The typical tank stress for it analogy is step one,734 psia.
Solution
To use the brand new IPR strategies, obtain take to suggestions, that has design cost, flowing bottomhole pressures, and you will an offer of average tank pressure. The data acquired from the biggest tension drawdown can be utilized that have Eq. 1 to solve into restriction oil-manufacturing speed.
Brand new estimated limitation petroleum design was dos,065 STB/D. Which worth will be always guess the production rate on other philosophy from streaming bottomhole demands to develop an entire inflow overall performance bend. Again, Eq. step one could be rearranged to estimate the production price to have good streaming bottomhole tension of 800 psia.
Fetkovich’s IPR demands several try factors to determine the latest deliverability exponent letter. Desk 2 reveals the test data prepared for plotting. The data is plotted towards good logarithmic graph, which is used to estimate the hill of the best-match straight-line from the study. The new deliverability exponent letter ‘s the inverse of the mountain. Just after letter is determined, Eq. step 3 can be used to imagine maximum oil development speed. Fig. step 1 ‘s the area of one’s investigation that displays an informed-fit straight line keeps a hill of just one.347 producing an enthusiastic n worth of 0.743. New projected limit petroleum creation price try step 1,497 STB/D, since Eq. 15 reveals.
Since limit rates are projected, it is used in combination with Eq. 3 in order to estimate production prices within most other flowing bottomhole challenges to help you write the fresh inflow efficiency bend in a manner just like you to demonstrated that have Vogel’s IPR. To have Fetkovich’s means, the production price are estimated to-be step one,253 STB/D during the a running bottomhole tension out of 800 psia.
To put on the process off Jones, Blount, and you may Glaze to that particular research lay, Table step 3 try prepared while the research plotted to your a coordinate graph since the revealed when you look at the Fig. dos. An informed-match straight-line yielded a mountain out of 0.0004 psia/(STB/D) 2 , the turbulence coefficient b. The new intercept ‘s the laminar flow coefficient and that’s computed to help you feel 0.23 psia/STB/D. These philosophy can be used for the Eq. 5 to select the maximum petroleum development price of just one,814 STB/D if the moving bottomhole stress are 0 psig.
This same matchmaking is utilized so you’re able to imagine the production rates during the almost every other streaming bottomhole demands to generate the brand new inflow performance curve. For a flowing bottomhole stress away from 800 psia, the production rates is actually projected as step 1,267 STB/D.
From this analogy, each of the around three methods yielded additional beliefs for the maximum petroleum design speed and creation speed at the a great flowing bottomhole stress of 800 psia. Thus, development rates is determined by the brand new IPR used in the study, together with oils engineer should become aware of that it concern inside the one data undertaken.