Study Design And Optimization Of Volume Fracturing In Tight Sandstone Gas Well

Dense gas in China is widely distributed, resource potential is enormous, but due to most the poor tight gas reservoir which developed layered sand body, small thickness, generally develops natural fractures, it is limited that transformation ability of simple fracture duo to conventional water pressure fracturing to the whole body of tight gas reservoir, an single well yield is low, unable to do much better exploitation of the benefit, so we must introduce more effective fracturing measures. In this paper, mechanism and application of the formation the volume fracturing of tight sandstone gas wells are studied in this paper, which aims to provide theoretical basis and technical support for the development of the volume fracturing of tight sandstone gas reservoirs.Firstly, the geological characteristics and formation mechanism of tight sandstone reservoir are studied, and the slip effect, stress sensitivity and seepage characteristics of the reservoir are analyzed.Established the tight sandstone reservoir fracture crack model and the extension of the discriminant model, through the crack network formation conditions were studied and the volume fracturing fracture- making process is simplified into three stages, analyzes each stage of the rock should force variation and crack extends into the situation, determine the main factors affecting the effect of volume fracturing volume.By means of numerical simulation, analyzed the influence of crack spacing, perforation parameters, preflight percentage, average sand ratio and displacement of tight sandstone fractured volume fracturing transformation size and volume. The results show that with the increasing number of clusters, the crack volume gradually increased transformation; with the increase of crack spacing, crack volume gradually reform reduce the crack spacing and crack;cluster high ratio is greater than 1.5 times, the mutual interference between cracks is smaller,on the other hand, the smaller the distance between the clusters, the more serious interference between cracks is generated; with the preflight percentage and displacement increases,fracture length gradually increased, but the increase rate decreases as the average sand ratio;the increase of fracture length and fracture network volume increased at first and then decreased.This paper analyzes various factors that affect the volume of fracturing in tight sandstone reservoirs, and provides a new idea for the volume fracturing design of tight sandstone reservoirs.