Numerical Simulation Study Of Fracturing Horizontal Well In Low Permeability Reservoir

In recent years, with the increasing number of horizontal well and the improvement ofbig fracture treatment technology, the way of horizontal well technology combined with thelarge-scale fracturing technology has become the primary means of developing lowpermeability reservoirs. To guide the fracturing transformation of horizontal wells, throughthe optimization of horizontal wells fracture parameters and well pattern parameters by theway of numerical simulation, has an important practical significance in improving thedevelopment effectiveness of fractured horizontal wells.Based on two-dimensional finite element model for oil-water two-phase, the finiteelement equation of the oil phase pressure and water saturation is solved. Using Mixed-cellfinite element method and applying finite element numerical simulator, uniform mathematicalmodel is established by regarding reservoir and fracture as one system of percolation.Fractures and horizontal section are represented as one-dimensional line elements. Matrix issubdivided by arbitrary triangular unit. The backward-difference which has good stability isadapted to discretized time. The influence that the fracture parameters and the well networkparameters have on productivity of fractured horizontal well is studied by numericalsimulation. Optimizing various parameters provides theoretical guidance for horizontal wellfracturing design.In this thesis, the hydraulic fracture horizontal well with six well injection one wellproduction pattern was studied numerically in Changqing oil field. Many influence factorssuch as fracture number, fracture length, fracture interval, fracture conductivity, pattern sizeand horizontal segment length are accounted. Several useful conclusions have been obtainedaccording to the analyses of the pressure field, such as saturation distribution and dynamiccurve of daily fluid production rate, daily oil production, cumulative fluid production andwater content in different parameters. Then the optimal values of the parameters were got bycomprehensive analysis. The Research shows that for specific reservoir and the permeabilityand fracture conductivity of a given parameters, fracture number, fracture length, fractureinterval, fracture conductivity, pattern size and horizontal segment length are not the biggerthe better, there should be the best values.