Since the beginning of Eagle Ford development in 2010, the artificial lift strategy has continuously evolved, transitioning from gas lift with side pocket mandrels to conventional gas lift completions, plunger lift, and rod pump installations. Most recently, there has been an increased understanding of late-life behavior. These phases occurred over a brief time span of only 13 years. The unconventional reservoir characteristics of the Eagle Ford shale allow us to observe the well life cycle from natural casing flow to late life in less than 10 years, a phenomenon not commonly seen in conventional reservoirs.
This paper will discuss the processes, methodologies, tools, and efforts that Eagle Ford Operations have embraced during this period to succeed in this uncharted territory. Key considerations include processing conditions (such as pad facilities and gathering system configuration), compressor capabilities, separation/processing systems, inflow performance relationship (IPR), and automation capabilities within the asset. Additionally, the paper will explore gas critical rate behavior.
Finally, the paper will present a well life cycle map illustrating the current exploitation/production strategy. It will also discuss the necessity of developing internal tools, designing field tests, and adapting conventional concepts to effectively manage the complex and transient nature of this unconventional reservoir.
Recognizing that unconventional reservoirs decline more rapidly than traditional ones and exhibit distinct behavior compared to conventional reservoirs, specific processes, strategies, and operational approaches were necessary to economically produce these novel reservoir types. These factors have played a crucial role in the development of shale resources. In the case of the Eagle Ford, operators grappled with determining the optimal drilling, completion, and production methods. Some operate in areas where the Condensate Gas Ratio (CGR) was extremely low (high gas production), and economics were difficult. Other operators were exploiting areas with poor petrophysical properties and lower reservoir pressure, which made it more challenging to succeed in this complex shale formation.