Unlocking Fuel Gas Reduction to Enhance Sustainability in Oil and Gas Operations

Abstract Methane emissions pose a critical challenge in the oil and gas industry due to their high global warming potential. The purpose of this paper is to present a comprehensive study to reduce fuel gas consumption and methane emissions. In alignment with the company's sustainability agenda and methane mitigation strategy, a methodical approach has been implemented to reduce fuel gas consumption, which consists of 90% methane. This initiative encompasses modifications in operational philosophy augmented by dynamic process simulation, along with continuous monitoring and control mechanisms to ensure optimal fuel gas usage. This paper presents an 18% decline in fuel gas consumption, equating to 1002 MMSCF reduction at one of largest onshore gas oil separation facilities. The Gas Oil Separation Plant (GOSP) processes crude oil extracted from over 600 wells, conducting phase separation into associated gas, crude oil, and produced water. The associated gas undergoes further processing, while dry lean gas (comprising approximately 90% methane) is recycled back into the GOSP plants and used in gas injection operations. A dedicated task force was established to optimize the consumption of fuel gas, leveraging in-house expertise and implementing minimal procedural modifications. Utilizing a dynamic process simulation model, the team rapidly implemented several initiatives to achieve enhanced process optimization outcomes. Post implementing this novel approach 18% reduction in fuel gas consumption was achieved and the results were tested over a period of six months. The benefits achieved for this initiative include: Optimization of gas injection compressor (gas turbine drive) during the hot season and running it in the winter, an automatic logic was developed to optimize and alert the DCS operator. This resulted in a net fuel gas saving of 13.5 MMSCF per annum. The substitution of nitrogen for fuel gas in three wash water tanks resulted in a savings of 230 MMSCF of fuel gas. The adjustment of the standby flare's logic achieved an annual reduction of 4.52 MMSCF. The optimization process applied to one of the four produced water tanks that yielded an annual savings of 394 MMSCF. The modification of the oil flow suction tanks blanketing system led to a conservation of 360 MMSCF of fuel gas. Implementation of smart Leak Detection and Repair (LDAR) program. The dynamic optimization of fuel gas using process simulation software within the blanketing system, motive gas, flare pilots, and gas turbine fuel has resulted in notable benefits. These include a reduction in fugitive emissions, significant fuel gas savings, and enhanced operational efficiency. This optimization strategy can be implemented in other gas and oil separation plants and facilities.