Publications

Kotabatak is a mature waterflood field in Sumatra basin. The vast majority of the 18,000 BOPD comes from the Bekasap formation sands. A much smaller contributor to the production is from the shallower, but tighter Telisa formation sands. Starting in 2006 a fracturing campaign was initiated in the Kotabatak field focused on the Telisa 2 sand in an effort to increase the recovery from the Telisa formation.From 2006 to mid-2008, 21 Fracturing jobs wereperformed to stimulate Telisa Sand in an effort toincrease production and recovery factor from theTelisa Sand of Kotabatak Field. The treatment design for 21 jobs averaged 200,000 lbs of propant. The 21 jobs resulted in an average oil gain of 82 BOPD per well and the overall success rate was 71%. As a result of the 28% failure rate, the Cost of Poor Quality (COPQ) was a relatively high $67,000 per job.Given the cost of the fracture jobs and the significant variance in production performance through mid-2008, it was decided to engage in a comprehensive study to improve the fracturing process from its current state to increase success rate, reduce COPQ, increase oil gain, and optimize the amount of propant. Lean Sigma, a business improvement methodology that maximizes shareholder value by achieving the fastest rate of improvement in customer satisfaction, cost, quality, process speed and invested capital, was used for improving the process in Telisa Fracturing Jobs through the Define, Measure, Analysis, Improve and Control phases (DMAIC) (Dhani G. Daradjat & Iwan Wijanarko, 2003). Based on analysis results, a proposed solution grid was generated to select the best candidate criteria, optimize the amount of propant and improve the cross functional team communication process. The candidate selection criteria were chosen based on reservoir properties: porosity, deep resistivity and water saturation. The amount of propant was optimized from 200,000 lbs to 160,000-180,000 lbs. A new communication process flow among the team was also developed to improve process implementation.From 1 December 2008 till 1 August 2009,Kotabatak executed 13 fracturing jobs in TelisaSand using recommendations based on the LeanSigma analysis. Compared to fracturing job resultsconducted in 2006-2008, success ratio issignificantly improved to 92% and COPQ reducedto be $22,231. Average 60 days oil gain increasedmore than 125% from 82 BOPD to 185 BOPD, andcost savings were achieved by reducing the amountof propant from 200,000 to 169,900 lbs. The Lean Sigma process proved to be a very powerful methodology for achieving high results through good processes. Improved financial benefits including revenue increase, operating expense savings and reducing cost of poor quality were achieved by improving the process of identifying fracturing candidates and optimizing the fracturing in the Telisa Formation of the Kotabatak Field using Lean Sigma recommendation.