Evaluation method for abandoned coal mine gas storage reservoir sites

Abstract

Underground gas storage plays an important role in the strategic reserve, peak shaving and stable supply of natural gas. Due to the complex geological conditions in China, very limited sites are available for the construction of gas storage. Thus, it is a good choice to build gas storage in the abandoned coal mine with rich resources. For this purpose, it is particularly important to establish an evaluation method for abandoned coal mine type gas storage. Hence, the factors affecting the conversion of abandoned coal mines into gas storage were summarized and analyzed based on the research results of gas storage site selection at home and abroad from the five aspects of hydrogeology, caprock tightness, geologic structure, influencing factors of abandoned coal mine, and other safe and economic factors. Then, a fuzzy comprehensive evaluation model based on hierarchical analysis was established and a comprehensive evaluation table of storage sites was prepared to evaluate the sites of abandoned coal mines. Besides, the evaluation model was applied to the site evaluation of a coal mine in Shaanxi. The evaluation results show that the coal mine is at an excellent grade and has the potential to be transformed into gas storage. Generally, the evaluation method has certain guiding implications for China to develop abandoned coal mine type gas storage.

Keywords

• abandoned coal mine
• underground gas storage
• site evaluation
• fuzzy comprehensive evaluation method