Optimization Of Parameters In Volume Fracturing Based On Maximize Productivity Of The Shale Gas Wells

As one kind of unconventional gas, shale gas is not only clean energy with good performance, and also has amazing reserves. Experts predict that shale gas is expected to replace oil, coal and other traditional energy sources, and will become new independent energy. Therefore, it has important theoretical significance and application value to volume reconstruction numerical simulation based on hale gas production capacity. Based on the theory of fluid mechanics, finite difference equations and numerical reservoir simulation volume of shale gas reservoirs, we established the model of shale gas seepage and the model of shale gas wells productivity model after fracturing process. Through the numerical model, we studied numerical simulation of several parameters of shale gas production, which provided theoretical basis and guidance for the actual shale gas exploitation of volume fracturing.By analyzing the mineral composition of reservoir rock, natural fractures, rock mechanics characteristics and fracturing mechanism of volume fracturing, the fracture parameters were obtained, including fracture length, fracture height, etc, which can be used for the late numerical simulation. Considering shale gas adsorption and desorption characteristics, gas and water two-phase flow mathematical model and fractured well productivity model were established, then dispersed the established model and established a differential equation.According to fracture parameters and volume flow field parameters, geological model was established, and based on the geological model and the mathematical model, the shale reservoir after fracturing was simulated. The correctness of this article was verified with comparing to the actual Eagle Ford shale gas reservoirs capacity. With the established model, the various parameters that affect the productivity of shale gas wells performed a sensitivity analysis, and the suitable optimization parameters increasing productivity were obtained.Compared with the shale gas horizontal well productivity of the traditional fracturing way and that of volume fracturing, the results showed that: the traditional hydraulic fracturing had greatly expanded the scope of pressure drops in the reservoir, but the pressure drop range of the volume fracturing will be extended to a larger area with more capacity. Among the shale matrix parameters, the shale permeability affected production capacity larger. When the permeability increased, the pressure drop across the reservoir and capacity could have a significant increase. In addition, shale matrix parameters such as porosity and thickness of the shale gas reservoirs could also have different effects on the production of shale gas. Under the conditions of the geological model, 9 crack was the optimal value, which means that when spacing was in 120m-130 m, cracks capacity would be in the range of optimal values. Also when the angle between the crack and the horizontal well was 90 °, the shale gas production wells would be the greatest.