Calculating BHP in a Gas well

[billyjackoil]

Does anybody have an know how to calculate BHFP from surface conditions in the annulus of a gas well. I'm using the effective diameter based upon the crosssectional area of the annulus to determine the friction loss for the calculation. Is this valid or is there another adjustment that needs to be made for annular flow?

 

[zdas04]

It helps to know how much water and froth the gas is bubbling through. The equations that I use (i.e., the Gray Correlation which is a series of steps) have a term for a gas static head.

I don't find any of the arithmetic to work very well below about 150 psig surface pressure, and most of them are really crap below 50 psia surface pressure.

David

 

[billyjackoil]

Thanks.

I am comfortable that in an annulus the hydrostatic head portion of the calculation is OK. The problem is the friction loss caused by the flow rate. I can also handle that using the normal calculations, but all I have is the adjustment using the ID. to the power of 2.667 in round tubing. I just don't know whether using an equivalent diameter based upon the crossectional area of the annulus will give the proper answer.

 

[zdas04]

No, calculating the equivalent diameter using the area will not give you a number that means anything. Take a look at faq378-1142 and pay special attention to the "Petroleum Method". I've used it for years with repeatable results.

David

 

[billyjackoil]

thanks,I'll lookat it.