Enriching Field Value: Enhancing Oil Production in Unmanned Jacket Platform, Offshore East Malaysia Through Water Injection Module Rejuvenation

Abstract Managing the late field life of assets in Sarawak water using old, deteriorating water injection facilities with high downtime impacting reservoir recoverability. Rejuvenating small, compact, fit-for-purpose and low-cost Portable Water Injection Module (PWIM) as a quick approach to continue reaping the benefit of Improved Oil Recovery (IOR) method from pressure maintenance. High downtime due to wear and tear issues from more than ten (10) years of PWIM use led to an increase in operational and maintenance costs. The impact is heightened as the low performance posed a huge threat to the Reservoir Management Plan (RMP), triggering the criticality to restore the unit to maximize reserves. Reservoir performance is reassessed together with well deliverability to inject water, aiming to remodel the unit to fit the late-life requirement. A market survey was conducted to find the best provider that can deliver the intended performance at the most interesting cost option. The water injection specification is a mandatory guide for PWIM deliverability criteria to safeguard the reservoir and topside facility from any flow assurance issue (souring, etc.). PWIM utilization has been introduced into this heavily compartmentalized field since 2013, proven to improve recovery by maintaining reservoir pressure and prolonging well deliverability via simple processing facilities. This PWIM, equipped with a few modular units (filtration, pump, etc.), was well suited for a platform with limited deck space. PWIM managed to deliver water injections with performance averaging around 65% uptime post six (6) years installation and dropped to below 40% due to issues such as pump failure, tank leaks, genset problems, etc. A declining trend of reservoir pressure can be seen as an impact of poor performance of the PWIM, prompting alarming RMP. Reviving the unit is an immediate action taken to remedy the worsening situation at a cheaper cost. The economic model run indicated that a new, smaller PWIM is a better option as compared to the old high-spec PWIM which requires skyrocketing operational costs. The novelty of rejuvenating cheaper, fit-for-purpose and compact PWIM as a viable economical IOR option at late field life to maximize full field potential. A preferred option is to operate the unit in a limited footprint jacket platform without jeopardizing surface facilities and safeguarding the reservoir from flow assurance issues. The insights from this study can be used as a guide for similar fields in the region that are facing similar constraints, especially in the context of aging infrastructure and the need for cost-effective IOR solutions in late-life fields.