Publications

“Ibu” field is one of mature primary field located in Wilayah Kerja (WK) Rokan, PT. Pertamina Hulu Rokan. First oil flowed in 1976 and reached peak production in 1983 with 9600 BO. Strategy production comingled with simple ESP completions. Current cumulative oil production was 34.7 MMSTB with RF ~19%. Since March 2018 to June 2021, no active drilling campaign due to reach End of Concession and found significant decline production first year after no drilling campaign. Historically, Well-by-Well review was commonly used and rarely considering Full-field perspective for field analysis. This workflow gives inconsistencies in identifying problems and potentials for Work-Over (WO), therefore often resulting in un-clear strategy for reservoir management of the field. In 2019, the team initiated a different way of reviewing and identifying WO potentials from well basis to full-field basis resulting more robust review and WO candidacy. Go-forward Full-Field basis review method was compensating complex of stratigraphy play and structural framework leading to WO focus reviews into 5 regions. Integrated study has been done by conducting connectivity analysis, High Resolution Stratigraphy, Current Oil Water Contact (COWC), and integrated reservoir production strategy plan. Significant results can be seen by looking at several deliveries: > 20 candidates in 1 cycle review, success ratio WO increases to 60%, average WO gain performance ~ 86 BOPD/Well, and incremental oil gain to date is ~192 MBO. Field performance significantly maintained by shown inclining performance to -6,46% (2019-2020) compared to 2018 performance (decline 72%). This effort is beneficial for further field development to enhance strategy of reservoir management e.g., WO potential, New Zone Behind Pipe, fracturing, and future infill/development well candidates. By having to use all available data and resources to do integrated subsurface and engineering analysis and review process, the overall outcome provide an excellent optimization strategy for the complex stratigraphy play field such as “Ibu” Field. This workflow should be applied for other mature field to economically extend life of this complex field, achieve high recovery, and maintain production decline.