Integrated Well Spacing Optimization by 3D Geological and Geomechanics Modeling—A Case Study from the TF Gas Field in the Sichuan Basin

As an important type of unconventional oil and gas resources, lacustrine tight sandstone gas reservoirs have been playing an increasingly significant role in China’s oil and gas reserve growth and production increase. This study focuses on the TF gas field J2s1 reservoir in the Sichuan Basin, which is characterized by low porosity and ultra-low permeability. The research aims to analyze the geological and geomechanical characteristics of the reservoir and optimize the development strategy to enhance development efficiency and economic benefits. Based on geological, well logging, and seismic data, this study comprehensively analyzed the geological and geomechanical characteristics of the TF gas field J2s1 tight sandstone reservoir. A three-dimensional geological and geomechanical model was established using multi-information constraints. On the basis of the model, a geological-engineering “dual sweet spots” evaluation was conducted to optimize well placement and well type selection. Additionally, numerical simulations of different horizontal inter-well spacing values, ranging from 400 to 700 m, were performed to assess their impact on development outcomes. The study revealed that geological and geomechanical parameters significantly affect the development effectiveness of the TF gas field J2s1 reservoir. The optimal horizontal inter-well spacing was determined to be 500 m through EUR simulation results. This spacing effectively balances resource utilization and operational costs, avoiding both excessive engineering expenses due to overly close well spacing and inefficient resource exploitation caused by overly wide spacing. The optimized development strategy significantly enhanced development efficiency and economic benefits in the study area and provides a reference for the development of similar tight sandstone gas reservoirs.