Understanding Critical Gas Rate Behavior in Eagle Ford Wells, Considering its Unconventional Reservoir Conditions

Abstract Since the discovery of the Eagle Ford reservoir, multiple artificial lift strategies have been applied in the field to optimize final recovery by well. Different operators have tried specific artificial lift methods depending on the location of the wells in the field. The gas-oil ratio of the field varies from northwest to southeast. ConocoPhillips was fortunate to develop areas where the gas-oil ratio is between 2,500 and 5,000 scf/bbl. In the areas where ConocoPhillips is currently operating, rod pumps, continuous gas lift, gas-assisted plunger lift, and intermittent gas lift have been used. As of August 2024, continuous gas lift is the most used artificial lift system by ConocoPhillips and has been active since 2012. During the early years of field exploitation, different correlations and processes for optimizing gas lift injection were used according to accepted concepts related to critical gas rate. According to these correlations and processes, the critical gas rate in the field should be between 500 and 600 mscfd. In 2017, while forecasting gas lift consumption for the entire field for the following 20-30 years, the company realized that the profitability of the field could be at risk if gas lift consumption continued increasing at the levels of those days. Upper management required immediate actions from the Operations Organization to maintain or improve the future economic indicators of the field. In this paper, the team will explain the foundational concepts that were developed, the field tests executed, and the full-field implementation activities performed from 2019 to 2024 to change the trend of gas lift consumption in the field. These efforts aimed to increase gas sales for the company, improve gas lift consumption, create a consistent production strategy, and generate a new, innovative production optimization process in Eagle Ford. Finally, the team will discuss how the high level of instrumentation, automation, and control played an invaluable role in these activities, and how the development of tools based on real-time information supported these processes.