Simulation Study on the Influence of Fracture Distribution Mode on Gas Production in Horizontal Wells in Tight Sandstone Gas Reservoir

Abstract

AbstractHorizontal well-staged fracturing technology is the most important stimulation technology for the development of tight sandstone oil and gas reservoirs. However, when using this technology to develop tight sandstone gas reservoirs, there are still some problems. Traditional fracture layout theory can no longer meet the increasingly complex well conditions. Therefore, it is urgent to compare conventional and unconventional fracture layout methods according to the characteristics of tight sandstone gas reservoirs. To guide the development of tight sandstone gas reservoirs with the lowest fracturing cost and the highest productivity, comprehensive and systematic research is needed. Therefore, based on the gas reservoir numerical simulation theory combined with fracturing numerical simulation software, this paper analyzes the influence of different factors and different combinations of fractures on gas production in the tight sandstone gas reservoir of Sulige Gas Field. Combining numerical simulation results and orthogonal experiments, the horizontal well fracturing layout plan is optimized. The simulation results show that the stimulation effect is better when the segmented fractures are distributed symmetrically along the central axis of the horizontal wellbore; when the segmented fracture spacing is small at both ends and the middle is large, the adjacent fracture spacing ratio is 0.9 when the production effect is the best; When the two ends of the fracture length are long and the middle is short, the production effect is best when the ratio of adjacent fracture lengths is 0.8; the orthogonal experiment results show that the segmented fracture length has a greater impact on gas production than the segmented fracture spacing. The simulation of the unconventional way of laying joints shows that the gas production is higher when the joints are placed in locations where relatively higher gas saturation and permeability exist, and the distribution of natural fractures will further increase the gas production. KeywordsTight sandstone gasHorizontal well fracturingFracture arrangementOptimization design