Study on fluid loss mechanism of fracturing fluid in coal reservoir
Liu Jianhua1, Wang Shengwei2,3, Zhang Xiaofei4, Zhang Yechang5
1. Shanxi Institute of Engineering and Technology, Yangquan 045000, China; 2. Facuty of Earth Resources, China University of Geo-sciences (Wuhan), Wuhan 430074, China; 3. State Key Laboratory of Coal and CBM Co-mining, Jincheng 0480061, China; 4. Taiyuan Branch,China United Coalbed Methane Corporation Ltd., Taiyuan 030000, China
The fluid loss of fracturing fluid in coal rock is closely related to joints and micro-fractures in coal. Based on the analysis of the classical fluid loss model, the relationship between fracturing fluid loss and coal reservoir pore fracture and permeability was studied. During the fracturing process, the fracturing fluid extended to the fracture wall facing the coal reservoir. The main channels of percolation were the tiny fractures in the coal reservoir and the pores on the main fracture wall. Porosity of coal reservoir was one of the decisive factors affecting the fluid loss of fracturing fluid. Matrix permeability and fracture permeability jointly affected the fluid loss rate of fracturing fluid. During the fracturing implementation, the fluid loss of the fracturing fluid was not harmful, and only through partial filtration of the fracturing fluid, the filtrate could enter some small micro-cracks near the main crack, and the micro-cracks were mutually the connections, even to the main cracks, eventually formed a complex network of cracks, which was the mechanism for the effective fracturing transformation of the fluid loss.
刘建华1,王生维2,3,张晓飞4,张业畅5. 煤储层中压裂液滤失机理研究[J]. 煤炭与化工, 2019, 42(9): 62-65,69.
Liu Jianhua1, Wang Shengwei2,3, Zhang Xiaofei4, Zhang Yechang5. Study on fluid loss mechanism of fracturing fluid in coal reservoir. CCI, 2019, 42(9): 62-65,69.