Finite Conductivity Vertical Fracture Of Production Computing And Numerical Simulation

Hydraulic fracturing is a mature and effective measures to increase production and injection. Because hydraulic fracturing plays a very important role in the oil production, it has been paid more attention by scholars and engineers. In the low permeability and tight gas reservoirs, many gas wells can not get the industrial air flow without water conservancy fracturing, and can not produce.Because of the great influence of the compressibility of natural gas, the hypothesis of micro compressibility can not be used, so the control equation is nonlinear. Even though the quasi- functional method can be used to simplify the seepage control equation of natural gas into the same form as the flow control equation of the micro compressible fluid, but the diffusion coefficient in equation is always related to pressure, and it is difficult to resolve accurately. The reliability of these analytical methods must be verified when we use them to guide the actual production.Paper chooses Hall-Yarborough(1973) method to calculate natural gas compression factor.Select Lee-Gonzalez-Eakin(1966) method to calculate the viscosity of natural gas. Using material balance pseudotime methods solve the gas reservoir control equation. Using Laplace transform to solve the unstable seepage model of a straight well and a limited diversion vertical fractured well in a rectangular formation, and the corresponding fast calculation method of the shaft wall flow is accomplished, the examples of yield analytical solution of the vertical wells and finite conductivity vertical fracture wells under the constant flowing pressure situations are obtained. The accuracy of the analytical solution is verified by Eclipse numerical simulation software.This paper also analyzes the impact of near-wellbore grid size and time step size to ordinary vertical wells numerical simulation results, and the effect of the grid size near-wellbore and fracture ends for finite conductivity vertical fracture wells numerical simulation result. And the effect of local grid refinement at fracture ends on the numerical simulation of multi fractured well is discussed. The paper gives a relatively reasonable numerical simulation method. The influence of the diversion capacity and the breakthrough ratio of the fracture on the productio of different reservoir is analyzed. At the end of the paper,it analyzes the influence of reservoir permeability and fracture conductivity on the optimal penetration ratio, and this paper analyzes the influence of reservoir permeability and fracture penetration ratio on the optimal flow conductivity variation law.