Study On Dynamic Mechanism And Design Method Of Volume Fracturing In Tight Sandstone Gas Well

Tight sandstone gas reservoirs has the characteristics of extra low permeability,using volume fracturing measures can increase reservoir fractured volume and improve gas production to meet the market demand.To study the mechanical mechanism and design method of volume fracturing has important guiding function for the fracturing construction and development of tight sandstone gas reservoir.Based on the activation of the natural fracture and the bifurcation of the fracture,this paper expounds the formation and process of fracture network.And from the point of fracturing load mode and energy balance analysis to study the necessity of fracture network propagation mechanics with fracture dynamics.Based on theory of dynamic fracture mechanics,mechanism of fracture network formation were studied,discovering that natural fracture ends both extended to form a complex fracture network,and there is a minimum pump rate of formation fracture network,the biggest influence on the critical pump rate is the length of the natural fractures,rock dynamic fracture toughness and elastic modulus.Based on the CMG reservoir numerical simulation software,different fracture network system are established,and research the influence of main fracture conductivity,secondary fracture conductivity,natural fracture conductivity on production,and study the effect on production contribution of fracture network size,and the main fracture conductivity,secondary fracture conductivity and fracture network size is optimized.Using Mshale module of Meyer fracturing software,combined with optimized fracture network size and conductivity,analysis the effect on fracture network form of formation rock mechanics parameters,construction parameters and fracture network parameters.And the effect on fracture form of all parameters is analyzed,finally,based on the analysis results to optimize construction parameters,and optimize the volume fracturing design scheme.