Process Optimization Strategies for Associated Gas Utilization and Flaring Minimization in Onshore Oil and Gas processing Facilities

An oil and gas field produces about 300 m³/day of crude oil and 50,000 SCMD of associated gas with liquid production supported by gas lift using high pressure gas from a nearby well. Currently, the associated gas is being flared due to the lack of gas evacuation infrastructure. To reduce flare and monetize this gas, a 32 km pipeline connecting to the local gas grid is under construction. This study identified optimal infrastructure and processing facilities to ensure the sales gas meets regulatory specifications while minimizing gas shrinkage and off gas generationConceptualized facilities include a compression unit, solvent-based Gas Dehydration Unit (GDU), and refrigerant based Dew Point Depression Unit (DPDU). Process simulations were performed using Aspen HYSYS software for compressor discharge pressures of 70 and 100 kg/cm²g. For each case, the sales gas, lift gas, and off-gas quantities were estimated for two lift gas withdrawal locations: downstream of the GDU and downstream of the DPDU Simulation results showed limiting lift gas diversion at the downstream of GDU and operating DPDU only on the throttled sales gas stream reduces off-gas generation and maximum sales gas availability. The optimized configuration meets water and hydrocarbon dew point standards at both supply and delivery points which is at 32 Km away. The otimized configuration also minimizes overall energy usage. The study also underscores the importance of off-gas recovery and utilization scheme to reduce flaring effectively.