WELL CANDIDATE SELECTION FOR MATURE FIELD OPTIMIZATION: CASE STUDY OF MATURE FIELD

• Main Author: Ayu Irfani, Wilda
• Format: Final Project
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/82019
• Institution: Institut Teknologi Bandung

Indonesia is targeting production of 1 million barrels of oil per day by 2030 by drilling more than 1,000 wells per year and reactivating inactive wells in a second batch. This effort involves analyzing the reactivation of idle wells based on remaining oil reserves and production track records to identify the reasons for temporarily decommissioning wells. The case study selected several candidate wells for optimization by calculating Estimated Ultimate Recovery (EUR) using reciprocal method and decline curve analysis, and recommended behind casing opportunity (BCO) in target intervals that contain hydrocarbons but have not been perforated. Data limitations prevented the calculation of the amount of hydrocarbons in the recommended BCO zone. In older fields such as W Field, with water cut of more than 90%, water diagnostic analysis using chan plot is used to evaluate field conditions. Future well performance was predicted by future Inflow Performance Relationship (IPR) through reservoir pressure drop sensitivity, while well optimization was carried out by replacing the Electric Submersible Pump (ESP) type according to the latest production rate test results and availability in the warehouse. The results concluded that the reason AG-07 was temporarily idle was because the water cut had reached 100% in 2015. Based on the production track record and the amount of remaining reserve in this well, it proves that AG-07 can be recommended for reactivation. In this case study, there are 3 low-performing wells and 2 high-performing wells. AG-04 is recommended to be used as a perforation target, because with the same formation, it can be seen that AG-1 and AG-5 have already been perforated, while AG-4 has not yet been perforated. By performing EUR calculation, three candidate wells with the highest remaining reserve were selected for water diagnostic analysis and well optimization, namely AG-01, AG-02, AG-04. Water diagnostic evaluation can use chan plot curves to determine the well condition between water coning or multilayer channeling. In this case study, the 3 candidate wells experienced water coning. This is validated by the very high water cut in this field. This well in the field W has a very high water cut, so a three-phase IPR was chosen to explain the well's ability to produce. The IPR curves with the Wiggins model for these three candidate wells explain that the flow rate of oil is very small compared to the flow rate of oil in the Wiggins model. This requires optimization using an artificial lift type electrical submersible pump with the aim of increasing the flow rate and changing the test rate into the rule of thumb. Optimization can be done by changing the type of ESP adjusted by the test rate range with the flow rate after sensitivity to reservoir decline, namely ESP type REDA DN440 with a range rate of 83-550 STB/d.