Publications

C field has been produced for more than 30 years, mainly from the conglomerate layer as the main oil layer producer. This main layer in the existing area was depleted in most of producing layers including the conglomerate layer. Thus, optimization in the existing wells to produce more oil become harder. Outstep drilling to find new potential area become the preferable option to give additional reserves and production. CMT-20 well, which was drilled as outstep well in a conglomerate layer in 2020, was a key well and would justify the next outstep development area. This well-produced oil from the conglomerate layer with high gas solution amount (GOR ~ 700 scf/stb). Produced with ESP become the only option, since the gas lift in the field is restricted and the other pumping method was unavailable.To maintain the production of this key well, dealing with the gas production is a must. Thus' a selective perforation strategy to reduce the gas amount production was chosen. Also, the Gas Lock Prevention Module (GLPM) was installed in ESP to prevent gas production in the later time (which was predicted with reservoir simulation and material balance analysis) due to the expanding secondary gas cap (weak water drive reservoir). Then, the specific pump parameter should be maintained to avoid the ESP problem. Using that combination, CMT-20 successfully produced with the average oil rate of 450 bopd and 6 months lifecycle and keeps producing until today. Before this solution, the CMT-20 lifecycle was less than a month. Therefore, the selective perforating strategy beyond the petrophysic concern and the combination with GLPM in ESP are needed to maintain the production of this key well. This method will still be used on the next development well and outstep well that targeted conglomerate layer as a default mode. There will be 3 more outstep wells that will be drilled in the upcoming year.