Three-Dimensional Development Characteristics and Fracture Network Interference of Atmospheric Shale Gas Reservoir

In order to clarify the characteristics of fracturing operation and the production dynamics of three-dimensional developing wells in shale gas reservoir, the Nanchuan atmospheric shale gas reservoir served as the subject for analyzing fracture interference phenomena, fracture network connectivity mechanisms, and their impact on the production of old wells. The statistics showed that the fracturing pressure of three-dimensional developing wells aligned vertically with geological static parameters, and exhibited a positive correlation with well spacing horizontally, while showing a negative correlation with the production degree. Affected by the reservoir’s physical properties and preservation conditions, wells in the lower gas layer exhibited better productivity compared to those in the middle and upper gas layers. When infill wells in the same development layer were fractured, based on the characteristics of casing pressure changes in old wells, the fracture network interference between old and new wells could be classified into high-conductivity fracture connection, high-low conductivity fracture connection, and low- conductivity fracture connection. Based on the interpretation results of well tests, the influence on estimated ultimate recovery (EUR) and typical curves of old wells caused by fracturing interference were classified into 4 types, while minimal impact were caused on the daily production levels of wells in different development layers. However, when zipper fracturing was conducted on shale gas wells in different layers with a spatial distance of less than 200 m, the fracturing pressure of new wells significantly increased. These research results have provided a theoretical basis for the plan deployment, fracturing design, and dynamic optimization and adjustment during the fracturing process in atmospheric shale gas fields.