Process Optimization to Increase Gas Handling Capacity by Debottlenecking Surface Equipment

Abstract Optimizing oil and gas production facilities that are already in operation poses unique challenges, as there is limited flexibility for modifications compared to facilities in the design stage. This paper presents an optimization conducted on an offshore gas processing and treatment facility, focusing on identifying and alleviating bottlenecks to enhance gas production and maximize revenue with minimal disruption. The optimization employed advanced process simulations and calculation tools to assess the operational constraints across various sections of the gas treatment system, including flowlines, piping, pressure safety valves (PSVs), vessels, and nozzles. The most critical bottleneck was identified at the inlet nozzle of the scrubber upstream of the TEG contactor, which restricted the facility's gas production capacity to 289 kSm³/d. Given the inherent difficulty and reduced flexibility in modifying an operational plant, the proposed solution was carefully designed to minimize capital expenditure (CAPEX) and required shutdown time. A spool connection to a dormant inlet nozzle was suggested to debottleneck the scrubber, increasing the facility's capacity to 370-390 kSm³/d. This approach was chosen for its low CAPEX requirement and the ability to implement the modification with minimal shutdown, thus reducing the risk of extended downtime and the associated production losses. Moreover, the necessity to reduce the cost per barrel of produced oil and gas drives engineers to challenge conventional designs while maintaining safe operations. The proposed modifications were developed by facility engineers working in operations, whose primary responsibility is to ensure continuous production that meets quantity and quality specifications, while also proposing innovative solutions to optimize performance and minimize environmental impact. The proposed solution was successfully implemented, and this was verified by the increased gas export from the production platform. Metering of the export gas showed an average export of over 250 kSm3/d which translates to an additional production gain of approximately 100 kSm³/d, equivalent to 668 barrels of oil equivalent per day (boepd), or 460 Mm³ over the period from 2026 to 2038, generating an estimated $41.6 million in revenue at a gas price of $2/btu. This optimization highlights the importance of innovative, cost-effective modifications in operational facilities, balancing production gains with the potential risks and costs associated with shutdowns.