Simultaneous Cracks Of Multiple Staged Fracturing In YANCHSNG Continental Shale Gas Reservoir

Shale gas is an important form of unconventional natural gas, China has the world’s richest recoverable reserves. To get the industrial gas flow, we must carry on the hydraulic fracturing, which is determined by the characteristics of low porosity and low permeability of the shale gas. Presently the computer aided engineering is developed rapidly, it becomes an effective and feasible way to simulate the shale gas staged fracturing by using numerical simulation methods.First the paper introduces the hydraulic fracturing technology. The numerical simulation of fracturing is reviewed and commented briefly. We use the Cohesive Zone Model of finite element method to simulate the fracturing. A two-dimensional axisymmetric model is constructed with YANCHANG continental shale gas reservoir characteristics. the fluid-solid coupling elements are used to simulate the formation rocks, and the cohesive elements are used to describe the behavior of fracture.The hydraulic fracturing process of the fracture is simulated on the horizontal well C1 in YANCHANG continental shale gas reservoir, the paper gives the change rule of crack morphology, the seam pressure curve, the distribution of pore pressure, stress distribution variation and fracturing fluid leakoff, the conclusion is of reference value for site construction.By adjusting the parameters in the above model, a simulation is carried out to figure out the effect of the parameters. Those parameters includes the initial principal effective stress, the elastic moduli of rock, the construction flow rate and viscosity of fracturing fluid, the research conclusion can be the valuable reference for the actual design and construction.Finally,a multi cluster fracturing model is constructed, it is used to simulate the multi cluster fracturing by adjusting the parameters, which including fracturing number of clusters, cluster spacing, fracturing order. Those conclusions of staged fracturing can get the guidance of horizontal wells oilfield cluster optimized multi-segmented design and site construction fracturing.