Three-dimensional fracture Propagation model and simulation study of CBM wells

Hydraulic fracturing is an important measure and main method to increase storage, production, and effective development of coalbed gas wells. And correctly understanding the morphology and geometric dimensions of fractures is the key to hydraulic fracturing stimulation. In order to understand the formation, analyze and evaluate the quality of fracturing construction, a three-dimensional propagation model of vertical fracture is established by using fluid mechanics and linear elastic fracture mechanics. The model considers the multi-layered and heterogeneous characteristics of the coal seam, that is, multi-layered coal seam thickness, in-situ stress, and rock mechanics parameters such as Poisson's ratio, elastic modulus and fracture toughness. The model can simulate arbitrary multilayered stress distribution patterns and the propagation of the fracture before and after the layer. Research and develop three-dimensional extension simulation software for vertical cracks of CBM wells. Through the calculation of the example, the calculated value of the established three-dimensional fracture propagation model coincides with the fracture parameter interpretation result, which verifies the practicability and reliability of the model.