Maximum Flowrate Equation
Maximum Flowrate Equation
(OP)
I am a new engineer in the O&G industry - I'm the only engineer for our small company. We currently have several gas wells in a specific area that were drilled several years ago, and we are scheduled to drill a few more in this area in the next year. My boss told me that when the first wells were drilled, 3rd party engineers told him that these wells were going to be "Tubing Limited" with 2 7/8" tubing and so 4" tubing was used. I need to find out the maximum flow rate for both of these tubing strings. I've searched all of my textbooks and can't find anything helpful. Can anyone coach me on where to start and what parameters I'll need? I know this is probably a simple question for some of you, but I've got to start somewhere!
Thanks in advance!
Thanks in advance!





RE: Maximum Flowrate Equation
RE: Maximum Flowrate Equation
RE: Maximum Flowrate Equation
I have to disagree slightly with Dcasto about the surface pressure not mattering. It sometimes matters a lot. There are two important steps in the process, first the gas must flow from the reservoir into the wellbore, then it must flow up the wellbore to the surface. Either of these can be limiting. If the inflow is limiting then lower surface pressure will seldom result in significantly increased flow (lower surface pressure will result in some combination of more flow and lower flowing bottom hole pressure). If the inflow is not significantly limiting then lower surface pressure will result in higher flow rate.
If the well is tubular limited then the only result of lower tubing pressure is increased friction in the tubing and little or no change in flowing bottom hole pressure or flow rate.
This stuff is fairly complex with some difficult interactions. They don't teach most of the practical stuff in college which is why small companies are ill advised to put new engineers in a position of operating a field without access to mentors.
David
RE: Maximum Flowrate Equation
Also, no I do not have Bradley's book, however as much as I've seen it mentioned on this website I'm starting to think that I may need to cough up the $700 or so to get it.
Thanks for your help.
Kyle
RE: Maximum Flowrate Equation
Bradley is an overpriced pig of a book with a seriouslly inadequate index and several internal inconsistencies, but I find myself going to it several times a week. I have other references that I go to first, but I often end up there.
David
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
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RE: Maximum Flowrate Equation
Thanks again
Kyle
RE: Maximum Flowrate Equation
Get a copy of the SPE Monograph of Well Flow. Then contact Dr. James Brill at the U. of Tulsa to get the errata if the SPE doesn't supply it with the errata.