Optimizing Deliverability in Gas Storage Reservoirs – Case Studies
Halliburton Energy Services, Inc., Kalkaska, MI,
MEHDI AZARI, MATT BLAUCH, VALERIE YEAGER, DANIEL DUREY, and CHAD JESTES, SPE
Halliburton Energy Services, Inc.,
BOB WALLACE, JOHN YATER, RANDY CLARK, RUSS FRAME, and KENNETH HOPPS, SPE
Stimulation techniques used in remediation of damaged gas storage wells can be significantly improved if damage mechanisms are properly identified. However, identification is only a beginning step in optimizing remediation. Determining the highest potential candidate wells and evaluating reservoir quality in the field are equally as crucial in a program designed to enhance well performance. Thus, reservoir and damage analysis becomes an important key in the process of properly ranking candidates and designing specific optimizing treatments. Once the diagnostic data and analysis has been completed, an operator then can begin the tedious process of ranking and validating the candidate wells’ potential by applying the resulting data, and then, selecting one or more tailored treatment designs.
This paper will illustrate that adequate well ranking is critical to assuring that AFE dollars achieve maximum deliverability. Case studies that used a “Solution Team” process in which over 75 wells were diagnosed and treated using damage identification and reservoir quality diagnostic results in five gas storage reservoirs are presented. Comprehensive diagnostic analyses, which resulted in damage-specific stimulation treatments based on the operator’s objectives to enhance existing deliverability, were employed.
In these studies, damage mechanisms were identified using improvements to methods described in a previous Gas Research Institute (GRI) project. Damage in each well was quantified using well test analysis and historical injection/withdraw cycle performance matching. Log analysis, petrophysical data, geological data, wellbore imaging, and work-over historical data were also used for treatment-design criteria. The deliverability improvement was quantified for each well using post treatment diagnostics. Each study incorporated several unique treatment options addressing a variety of damage mechanisms. Treatments were selected to produce the highest deliverability enhancement and maximize the operator’s return on investment (ROI).
In the case studies, high-pressure jetting, tailored acidizing, hydraulic fracturing techniques, damage-specific fluid treatments, and high-pressure jetting with foamed chemical treatments were used. The discussion will include the decision-making techniques used in each case and the application of the chosen treatment.
The post-treatment evaluations were updated with one-year and two-year follow-up evaluations to show how the “Solution Team” process significantly optimized deliverability by using the new and improved diagnostic practices.