Optimizing Gas-Flaring Solutions: Enabling Enhanced Oil Recovery and Power Generation

Abstract Produced gas is currently being flared into the atmosphere due to the lack of infrastructure to transport and sell the gas. We can re-inject this gas back into the formation, increasing the reservoir pressure and making the oil lighter thus enabling enhanced oil recovery. Additionally, the gas can be used to generate electricity during the highest energy demand times of the year to help stabilize grid usage. Prices would be monitored using real-time data provided by ERCOT to allow for rapid responses to changes in demand. There is a threefold benefit to this process: enhanced oil recovery, electricity generation, and a reduction in flared gas. Following prior work in the Wolfcamp formation (SPE 213002), we looked at four additional unconventional formations in Texas: Spraberry, Bone Spring, Austin Chalk, and Eagle Ford. Each formation had reservoir properties taken from published SPE literature to build a single well simulation model. Each model was tested using a cyclic gas injection schedule. The schedule consisted of three months producing, two months injecting, and one month of soaking. Three different gas injection rates were used to compare the additional incremental oil production for each case. The cases simulated were 1.5 MMscf/D, 3 MMscf/D, and 5 MMscf/D. Multiple economic evaluations were run to estimate the potential cashflow of the project in each formation. Assuming a gas engine with generator package costs $0.5 million, compressor $2 million, and a gearbox $0.3 million. The total cost of the project would be approximately $2.8 million. Assuming the current oil and gas prices of $80 and $2.75 respectively we estimate a return on investment of 2-3 years with additional oil production ranging from 30-80% based on the specific reservoir formation.