Slimhole Completion Experience in Java Sea, Indonesia: A Look Back on Performance of the First 40 Slimhole Wells

摘要

Slimhole completions have been applied worldwide for years.rnThe aim of this type of completion is to reduce well costsrn(drilling and completion) and therefore improve projectrneconomics. This paper presents the results of applyingrnslimhole completions into oil and gas wells in the OffshorernNorth West Java (ONWJ) Field, Indonesia. In looking back atrnthe performances of previous wells, this paper focuses onrnproblems associated with slimhole wells during completionrntime and their post-production compared with potential costrnsavings and future well intervention benefits.rnTo date, more than 40 slimhole wells have been drilled inrnONWJ fields. Typically, the wells were completed in 3-1/2”rnor 2-7/8” monobore. Cost savings were achieved throughrnthese completions. However, additional problems seem tornhave arisen during completion time that could reduce therneconomics of the project. The most frequent problem duringrncompletion was due to cement obstruction (22.2% from totalrncemented wells) in the liner section after the cementing job,rncaused by poor cement displacement. This commonlyrnoccurred on relatively deep and deviated wells. Fromrnprevious experience, drilling practice has improved, resultingrnin fewer operational problems during completion time.rnThe overall results show the problems associated withrnslimhole are still within an acceptable range compared withrnthe potential cost savings and benefits. In our case, productionrnrates from slimhole-monobore wells have not been muchrndifferent from conventional wells. This paper also sharesrnsome operational practice improvements made to reducernproblems associated with slimhole-monobore wells.