WHC Wellhead Compression Jim Hacksma 2 Jim Hacksma

WHC (Wellhead Compression)

Jim Hacksma 2

Jim Hacksma 3

Compression for Deliquification q As a solution for liquid loading, goal is to; Ø Reduce Ø Help carry liquid to surface q Works best on high PI wells Ø Those ü FTP ►Increase gas velocity ►Above critical most sensitive to pressure changes (Those wells that are not tight) Ø Wells with high PI ►High cumulative ►Low FTP Are the wells that respond best to compression ü They yield biggest production increases ü Jim Hacksma 4

What about tight wells? q Compression q Tight Ø No Ø If often fails to create critical flow wells often can’t exceed the CR matter how low the pressure the CR is not exceeded… Ø Liquid will not be removed… Ø Production Jim Hacksma won’t be increased 5

Compression vs. Venting q When Ø FTP venting a well to atmosphere is very low ►Only 14. 7 psi ►Or slightly higher q When compressing a well Ø What FTP would you expect? Ø Probably q If higher than when venting you can’t unload well when venting… Ø Then, Jim Hacksma no chance of unloading with compressor 6

Venting q See paper #63 on venting Ø Wells are tight Ø Operator Ø Wanted q Test to learn how much liquid removed by venting findings? Ø Venting q In tested effectiveness of venting didn’t remove much liquid this case, Ø Installing Jim Hacksma compression would be pointless 7

Would Compression Help You? q Would q Run a test; Ø Vent ü compression unload your well? your well to atmosphere Just for a short time Ø Does the well unload? Ø Does production increase significantly? q If neither is true; Ø Then, Jim Hacksma installing compression would be a failure 8

Compression w/ Other Methods q Prior slides point out the fact that compression can be a poor solution for loading q But, compression has great value Ø Works q My great with many GWD methods suggestion; Ø Use another GWD method for unloading your well Ø Add compression; ü Further reduce FTP ►Further increase production Jim Hacksma 9

Compression w/ Other Methods q Often works great with other GWD methods Ø Foam ►GL ►PL ►SRP ►VS Ø WHC can enhance most any other GWD method q Some problems Ø When using PL & WHC together Ø WHC is a continuous ►PL is an intermittent Ø When well SI during PL ops, gas shut off to WHC Ø Must Jim Hacksma often put WHC in recycle mode 10

WHC vs. Centralized Compression q Centralized Ø Cheaper q WHC than having WHC at each well often performs better ►Better results Ø Because ü compression (CC) often cheaper compressor closer to well Less friction loss ►Higher suction pressure ►More rate Ø Because WHC matched to each well When high PI & low PI (tight) wells on CC… ü High PI wells consume most of compressor capacity ü CC can’t reduce FTP as much on low PI wells ü WHC will reduce FTP more on poorest wells ü Jim Hacksma 11

Types of Compressors q There are many types; Ø Reciprocating ►Rotary screw ►Liquid ring Ø Sliding ►Rotary lobe q Each vane is very good ►Each has its purpose q For my purposes, however, I have always used reciprocating compressors Ø Though I have on occasion considered using a rotary screw compressor Jim Hacksma 12

How much? q How much will my well flow with a compressor? q Common Ø Then ØA to spend large $$ installing WHC learned production was far less than hoped failure q There is a better way ►Save $$ Ø Test your well ►Vent to atmosphere ►Short term Ø Thru separator ►Thru back-pressure valve Ø Back-pressure Ø Measure Jim Hacksma = expected compressor suction flow ►Cheap, reliable test 13

Miscellaneous q Reduce compressor suction (Ps) & FTP Ø Discharge Ø ∆P increased across compressor Ø What ü pressure (Pd) remains unchanged happens to compressor HP? Increase or decrease? q HP Ø At decreases ►Why? lower Ps, compressor moves less gas Ø And, because gas volume is down… Ø Compressor Jim Hacksma HP is down 14

Miscellaneous (cont’d) q Likewise; Ø Pd remains unchanged Ø Increase Ø What Ø HP Ps ►Decrease ∆P happens to HP? ►Increase or decrease? increases q As it turns out, compressor volume has far more influence over compressor HP than does ∆P across the compressor Ø Counter-intuitive? Jim Hacksma 15

Compressor Analysis q Few q. I engineers can analyze compressors recommend that you; Ø Download Ø Play Ariel’s design software with it Ø Learn more about compressor design Ø Don’t rely solely upon the sales rep for you compressor vendor Jim Hacksma 16

Questions? q Jim Hacksma q Consulting q Specialty Petroleum Engineer – Gas Well Deliquification q 832 -559 -7332 office q 281 -415 -4715 cell q 11903 Amyford Bend, Cypress, TX 77429 q Jim. Hacksma@comcast. net Jim Hacksma 17