The First Successful Rigless Monotrip Gas Lift Completion in Mahakam Field

Abstract

Pertamina Hulu Mahakam (PHM) has applied the Mono Trip Gas Lift (MTGL) completion technique with 27 wells that have been completed by drilling rigs. To improve efficiency, PHM assigned a Hydraulic Workover Unit (HWU) in September 2020 to execute the first rig-less MTGL in the Mahakam field, which is economically feasible based on an internal study. Since HWU has never performed the MTGL cementing, some collaborative works must be done to identify backlog and establish solid procedures for perfect execution. Besides, top of sediment (TOS) was found 16-21 m inside the tubing, which hindered access to the most bottom production zones. Moreover, this project is the first MTGL conducted inside a 7” casing which allows a maximum of 3 barrels per minute (bpm) flow rate (according to packer specification). The flowrate limitation could potentially create higher TOS inside the tubing. Hence, we agreed to utilize a 3.5” landing joint and to apply a higher flow rate for displacing cement as per simulation with rigorous risk assessment and mitigations. As a result, the job was completed in 11.6 days without a lost-time injury, contributing to 12% PHM saving, while the TOS was tagged 13 m above the top of the landing collar by 1.9” macaroni. Despite its success, some lessons are captured as our recommendations, such as improving the sweeping efficiency of the MTGL wiper plugs, establishing a solid system for vital data of cementing job, and developing the infrastructure by HWU contractor to perform the job more successfully. This paper strongly recommends the rig-less operation as an alternative way to reduce the costs of well construction activity. A proper operation can be achieved by learning the lessons, closely managing and monitoring entire job stages. Finally, it encourages partnership and synergy for a better result.