A New Breakthrough of Horizontal Well Stimulation: Improving Oil Production Through Stimulation CleanUp-JetAcid Method in Waterflood North Area

Abstract

The exploitation of LQR (low-quality reservoir) required advanced technology due to its difficulty to produce. The asset optimization team focuses on improving oil recovery from low quality shaly sand reservoir as the remaining reserve is attractive with typically low recovery factor only 22%. The horizontal well has been found as the best method to exploit remaining oil in LQR in Rocky Block. Waterflood North Area consists of 12 fields and maintains more than 178 horizontal wells. There are many challenges in horizontal well that leads to poor oil production performance. It’s found that low productivity in horizontal wells is caused by formation damage. Many factors contribute to its such as solid particle plugging due to poor lateral clean-up job at well initial completion and scale build up as an impact of utilized calcium carbonate mud drilling base and nature of water. A combination of RE-LCU (Re Lateral Clean-Up) and rotary high pressure jetting acidizing strategy might as a potential solution to improve productivity index of horizontal. The CleanUp-JetAcid method introduce a breakthrough to improve stimulation job success ratio in horizontal wells by providing excellent multi disciplines analysis at early phase of well candidacy process workflow until final execution process of RE-LCU and combine with rotary high pressure jet acidizing as technology available in market. New workflow of RE-LCU candidacy process established to improve understanding of horizontal well production performance within geology framework and leverage integration analysis among discipline to ensure all data are maximize use to solve problem. This workflow is designed to minimize uncertainty and risk in the early phase of screening horizontal wells and meets with root cause of low PI due to formation damage. To be able viewing the opportunity of RE-LCU in wider scale involving all fields in Rocky Block, then implementation of new workflow is completed as one standardized workflow process in reservoir level respective to reservoir management to identified higher quantity of wells candidate. A comprehensive effort through CleanUp-JetAcid method has been made to solve low productivity index issue in horizontal wells. Some significant impacts have been achieved from 2 pilot wells execution have successfully delivered 38.6 MBO. Many parameters shown outstanding improvement; Success ratio of RE-LCU stimulation increase to 100%; Oil gain increase 364% with additional Fluid rate improve almost 300%, the degree of RE-LCU job quality is excellent, turbidity of fluid is less than <90 NTU that never been achieved before compared to previous method. 49 more horizontal well candidates have been identified and reviewed as a part of expansion program. Replication of this method might as an opportunity to be implemented in old horizontal wells that have similar problems to improve oil production horizontal well.