Since 2003, almost all the development wells drilled in the Karachaganak field have been horizontal wells. Initially, the wells were completed open-hole, but since 2011 all new wells have been completed with multiple swelling packers and ball activated stimulation sleeves to facilitate selective stimulation.
Despite optimising the stand-off from the oil water contact and the poor reservoir quality of the aquifer, several wells have started producing formation water.
With limited water handling capacity at the surface facilities, formation water production is a threat to hydrocarbon production. Wells that produce water are either choked back or shut-in. Accurate detection of the water entry point and understanding how water migrates from the aquifer into the wellbore are therefore critical in developing effective water shut off strategy. Recent experience has shown that conventional production logging tool (PLT) technology is an ineffective at evaluating either of these aspects.
This paper describes how integrating data from Multi-Sensor Production Logging and Spectral Noise Loggig tools has been used to determine the downhole fluid flow path in a gas condensate reservoir and subsequently optimize water shut-off operations. The early results of this new approach will be presented.