Publications

Alpha block starts to suffer steeper production decline in 2020 leading to shorter economic life to 2022, while Producing Sharing Contract (PSC) terms expired in April 2027. In order to revitalize the asset, it is imperative to boost up the gas production to fulfill the existing Gas Sales Agreement (GSA) commitment value which has been below commitment since January 2022. Yet, high reservoir temperature brings another jigsaw to the puzzle, where handicap on pressure transient and flowing gradient data acquisition for the actual problem identification is present. The first step was to overcome the data handicap with unconventionally approach using surface shut in data. Meanwhile, Rate Transient Analysis (RTA) in 2020 and Pressure Build-Up (PBU) result in 2021 confirmed that skin build up has occurred in Zeta-1ST and Zeta-3HZ. This condition requires stimulation. Then, feasibility study and laboratory test was done to review the suitable stimulation method. Lesson learned from other field with similar reservoir profile comes as the study reference. As the result, it was settled to implement acid fracturing in Zeta-1ST, while matrix acidizing with nitrified acid in Zeta-3HZ. Stimulation project in Alpha Block was successfully delivered and the result surpasses expectation considerably with increase in maximum deliverability; from 9.3 MMSCFD to 25.8 MMSCFD (2.8 times) for Zeta-1ST and from 7.2 MMSCFD to 27 MMSCFD for Zeta-3HZ (3.7 times). Forecast of incremental production and revenue from acid stimulation is able to fulfill remaining committed quantity GSA until 2027. Also, it is potential to extend Alpha economic life from 2022 to end of PSC period or beyond and currently this block is preparing for new GSA.