Maximizing Production Within Integrated Facilities Through Flow Re-Routing and Backpressure Management

Abstract This paper illustrates how understanding facility limit, managing topside system pressures as well as optimizing product flow routing in an integrated oil-gas-condensate facility complex for mature fields are key to protecting and further optimizing base volumes while enabling volume gains from new wells. Low-cost and reliable execution of surface modifications via control valve, choke reinstatement and well mix optimization with strong integrated subsurface-surface network understanding are key ingredients in identifying and realizing the value from a potential unoptimized network. In a mature integrated oil-gas-condensate facility complex, understanding the facility limits, flow network and remaining subsurface potentials production profiles are crucial in finding ullage for flow routing optimization and back pressure management. The evaluation includes the use of integrated network simulator and wellbore hydraulic model software application on potential gains from system pressure reduction; followed by assessments to address subsurface-surface uncertainties from the existing network comprising Oil and Non-Associated Gas wells, and impact to network well mix and Gas lift optimization. Well level performance from well tests, network level performance from platform to separator outlet, gas lift and key surface equipment e.g., separators, pipelines and compressors history were some of the information used for the evaluation. The evaluation recommends splitting oil and gas wells to prevent backpressure impact, optimize the system pressures and utilize the full ullage of the integrated network gas compressor. Based on actual observation, the system pressure reduced by 26% which results in 8% of incremental oil gain. The integrated network simulator model recommends reduction of gas lift consumption, selective wells to shut in and choke down as we add more wells into the network to manage backpressure impact. Gas lift header pressure controls and well production chokes were reinstated and resized appropriately to enable production optimization. As a result, about 9% of total oil production was recovered from the optimized network, and a further 3% increase was observed from new wells post-network optimization. This paper will illustrate the challenges in a 40-year-old complex integrated network facility, with combinations of oil, non-associated gas and gas cap blow down production and approaches taken to address the challenged and continue to maximize overall production