Research has shown that the proper identification of damage mechanisms can improve stimulation techniques used to enhance deliverability in gas-storage wells. The damage mechanisms must be identified before the highest-potential candidate wells and their most effective treatments are determined. Additional data analyses are required to rank candidates properly and design specific treatments to maximize deliverability. Once the diagnostic data are collected and analyzed, an operator must apply the relevant data analysis to the selection of one or more tailored, effective treatment designs. Since many storage companies work from a fixed treatment budget, an adequate well-ranking process must be used for maximum deliverability of dollars spent. The wellranking process can reveal various options for enhancing deliverability with different treatments.

This paper presents case studies from an alliance project in which over 60 wells were diagnosed, treated, and evaluated in four gas-storage reservoirs. Comprehensive diagnostic analyses allowed the development of damage-specific stimulation treatments. New, rigorous processes were developed to evaluate damage and select appropriate treatment options

In this study, damage mechanisms were identified through the use of methods described in a previous Gas Research Institute (GRI) project. Formation damage in each well was quantified by well-test analysis and historical injection/withdrawal-cycle performance matching. Log analysis, petrophysical data, geological data, wellbore imaging, and historical workover data were also gathered as diagnostic treatment-design criteria. The deliverability improvement was quantified for each well based on post-treatment diagnostics. Each study uses several unique treatment options that address a variety of formation damage mechanisms. Treatments were selected to produce the highest deliverability enhancement and maximize the operators’ investment returns.

In Case Study 1, high-pressure jetting, acidizing, and hydraulic-fracturing techniques were used in a deep high-permeability pressure-drive carbonate reservoir. In Case Study 2, high-pressure jetting and damage-specific fluid treatments were used in two shallow-water-drive clastic reservoirs. In Case Study 3, hydraulic fracturing, high-pressure jetting, and extreme overbalanced perforation (EOP) surging were used in a shallow highpermeability pressure-drive clastic reservoir.

You can access this article if you purchase or spend a download.