Analysis of seepage mechanism and productivity model of multi-stage fractured horizontal well in tight sandstone gas reservoir

Abstract

During synchronous fracturing of horizontal well clusters, the induced stresses generated by multiple wells affect the formation of complex fractures. By using linear superposition and vector representation, the productivity model for the horizontal stress field between wells was constructed. The results demonstrated simultaneous fracturing can produce stronger and a wider range of stress interference variable impact on induced stress field, the most influential factor is the row spacing, accounting for 32.09% and the engineering factors with the least impact is fracture conductivity, with weight of 0.08%. The research results were used to YA gas field. After the preliminary implementation in the field, the initial production of a well in the reservoir increased by 20.48%, the decline rate slowed down by 13.16% and the output of well increased by 43.75% in the stable production period. In addition, these results might also provide an acceptable explanation for the high productivity of synchronous fracturing operations in horizontal well clusters. Generally speaking, a clear understanding of changes in induced stress fields in horizontal clusters might provide are liable foundation for the determination of optimal well spacing and a fracturing program for horizontal well clusters to develop unconventional formations.