Selection Criteria for Successful Water Shut-Off Treatment - Brown Field Success Story

Abstract

Abstract A brown-field which is located in Sumatra has been producing for more than 40 years. This field currently has high water production with average field water cut 98%. This condition is really burdening operating cost of this field since water production is continuously increasing. In order to reduce water production, reduce operating cost and increase profitability of the field, water shut-off treatments were preferred to be applied to several wells in this field. Those treatments successfully achieved good result which was decreasing water production (from 20,688 BWPD to 4,719 BWPD) and maintaining or even increasing oil production (219 BOPD to 525 BOPD) due to reduction of water-cut of water shut-off wells from 99% WC to 88% WC. Prior to executing water shut-off treatments program, all data, including historical well-work job and completion, production data, and reservoir data, were thoroughly reviewed to ensure the wells were properly selected for water shut-off treatments. After the treatments were completed, those data were reanalyzed to extract lesson learned for upcoming water shut-off treatments. Based on previously analyzed data and results of water shut-off treatments, in order to have higher probability of success ratio of water shut-off treatments, following things are must-have items that need to be considered: well’s diagnostic plot (WOR and WOR′) should clearly show that wells have water coning or channeling problem, well’s historical completion has not been treated with the same method of water shut-off treatment, and wells should have interval which is located above current oil-water contact (COWC). This paper describes the analysis method, candidate selection, and lesson learned of success and failure that may be used as selection criteria for selecting water shut-off treatments candidate to ensure higher probability of success.