Study of the optimization of an injection and production scheme of gas storage in depleted gas reservoirs based on a fuzzy comprehensive evaluation method

Abstract:

Gas storage is an important facility for seasonal and emergency natural gas peak shaving. The reservoir geological  
conditions and injection and production processes of gas storage are quite complex, which make the design of injection and
production schemes of gas storage more difficult. Considering that the decision of injection and production schemes of gas  
storage is affected by many factors, in order to obtain the best injection and production scheme of gas storage, this paper presents  
a fuzzy comprehensive evaluation method to evaluate and optimize the injection and production of gas storage. Firstly, a fuzzy  
comprehensive evaluation index system of gas storage injection and production is established as the basis of analysis and  
evaluation. This index system includes the injection and production well numbers, injection and production well layers, injection  
and production capacity, injection and production efficiency and injection and production energy consumption. Then the entropy  
weight method and an analytic hierarchy process are used to calculate the index weights. Based on a fuzzy membership function  
method, trapezoidal and ridge membership functions are selected to score the evaluation indexes. After the weight and score  
of each index are obtained, a linear weighting method is used to calculate the comprehensive evaluation result of the injection  
and production scheme. The whole paper focuses on the method and process of establishing a fuzzy comprehensive evaluation  
model of gas storage injection and production, which mainly includes the establishment method of the evaluation index system,  
the calculation method of index weight and the determination method of the index membership function. Domestic gas storage  
in a depleted gas reservoir is taken as an example to evaluate and optimize the injection and production scheme. This gas storage  
has a storage capacity of 5.88 ×108m3, a working gas capacity of 2.95 ×108m3 and an injection production well number of 13.  
According to the gas injection and production arrangement of the gas storage, the planned annual gas injection volume is 2.0  
×108m3 and the annual gas production volume is 1.5 ×108m3. Three gas injection schemes and three gas production schemes  
of the gas storage are evaluated and optimized. The results show that the comprehensive scores of the evaluated gas storage  
injection and production schemes are all above 70 points, indicating that the application effects of each scheme is good. Among  
them, the optimal gas injection scheme is scheme 2, and the optimal gas production scheme is scheme 3. Finally, the evaluation  
method proposed in this paper can provide guidance for the planning and management of injection and production of gas storage.


Key words:gas storage; injection and production scheme; comprehensive evaluation; fuzzy membership function; entropy weight method; analytic hierarchy process

Received: 2020-06-29

Corresponding Authors: lgcdjr@163.com

Cite this article:周军, 彭井宏, 孙建华, 肖瑶, 梁光川. 基于模糊综合评价法的气藏型储气库注采方案优选研究. 石油科学通报, 2021, 03: 494-504 ZHOU Jun, PENG Jinghong, SUN Jianhua, XIAO Yao, LIANG Guangchuan. Study of the optimization of an injection and production scheme of gas storage in depleted gas reservoirs based on a fuzzy comprehensive evaluation method. Petroleum Science Bulletin, 2021, 03: 494-504.

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