ABSTRACT
Volcanic gas reservoirs in China are rich, and natural fractures are developed in these reservoirs, which brings significant challenges to the development of volcanic gas reservoirs. Based on the discrete fracture network modeling and the combined finite discrete element method, this paper carried out the fracturing simulation research for a deep volcanic reservoir. Then, the influence of natural fracture distribution characteristics on the fracturing of volcanic reservoirs is discussed in detail. The results show that under the same discrete fracture network parameters and model parameters, the fracture initiation pressure error of volcanic reservoirs with natural fractures can reach 10 MPa, while the expansion pressure error is relatively small. The difference in crack width can be close to 2.1 times, and the difference in tensile failure ratio can reach 24.8%. The main fracture of fracturing tends to extend along or perpendicular to the dip angle of the bedding network. When the artificial fracturing extends along the direction of the bedding dip, the main fracture shape of fracturing seems to be smooth. However, when the main fracture of artificial fracturing tends to expand perpendicular to the bedding direction, the main fracture of fracturing is more tortuous. When the number and density of natural fractures increase, the time for fracturing to reach the boundary of the study area may be shortened, and branch fractures are more likely to occur during the expansion of main fractures. The above results have certain reference significance for the field operation of the deep volcanic reservoirs.
