Reverse Coning Method Application to Reduce Water Cut in ML-036 Well, Lirik Field Pertamina EP

Abstract

Produced since 1936, Lirik is a mature field in Asset 1 PT Pertamina EP with ±50% ultimate recovery factor averagely. This has an impact on high average water cut more than 99%, and is a special engineering and operational challenge. Engineering programs are applied to maintain oil production, such as well maintenance, optimization, reactivation, and repair. Unfortunately, gross up effort mostly bothered with excessive water production due to high water cut. Engineering innovation to increase oil production with reduced water cut becomes pivotal to avoid exaggerate investment, such as water injection well drilling or production facilities replenishment. Avoiding excessive water production, reducing water cut is a compulsion. ML-036 is a production well with high water cut, 98.8%. Using sucker rod pump as its artificial lift, the average gross and net production is 431 barrels fluid per day (bfpd) and 5 barrels oil per day (bopd) respectively. This paper aims to prove the effectiveness of reverse coning method in reducing water cut in ML-036 well and increases oil production. Technical approach using reverse coning method is used to overcome water coning as a cause of high water cut in ML-036 well. Proper design of reverse coning tool is prepared and installed using standard operational procedure. Parasol injection to clean the wellbore is initially applied, and the selection of tool installation depth becomes crucial. Some oil characteristics and parameters are considered to increase the degree of success, such as pay thickness, reservoir vertical and horizontal permeability ratio, pressure drawdown, aquifer strength, and well completion configuration. The economic evaluation is also considered as part of success parameter. The result of this study concludes the success of reverse coning method to decrease average water cut in ML-036 well. With proper tool design and depth selection, supported with parasol injection before its application, reverse coning can become an alternative solution for oil well with water coning problem.