Integrated Live Geomechanics Model to Unlock the Deep Shale Gas Reservoir

ABSTRACT: Shale gas reservoirs have become a significant energy source due to their commercial natural gas production. However, their inherent complexity poses numerous challenges for effective development. In this study, we introduce an integrated real-time geomechanics modeling workflow for deep shale gas reservoirs. This workflow utilizes extensive static and dynamic data, including various seismic attributes, precise 3D pore pressure models, anisotropic characterization and real-time micro-seismic data. This newly proposed workflow optimizes the quality of the geomechanics model. By adjusting the geosteering model for horizontal wells and correlating it with the true stratigraphic thickness (TST) domain, we achieve more accurate 3D structural modeling. Utilizing machine learning techniques, we extracted seismic attributes correlated with logging data to construct a reliable fracture model, which guides geomechanical modeling and hydraulic fracturing model. This model informs the design of geomechanics characterization and hydraulic fracturing. By iteratively updating the geological and geomechanical models with real-time micro-seismic data and engineering analysis, we achieved more precise stress characteristics and reservoir properties. The study results indicate that this integrated real-time geomechanics model, compatible with horizontal well drilling data, significantly improves stress accuracy, identifies sweet spots in the reservoir, and provides robust support for reservoir development. 1. INTRODUCTION There are abundant marine shale gas resources in the Sichuan basin, located in southwestern China, form a large and complex superimposed basin on the northwestern edge of the Yangtze Plate. There are six main sets of hydrocarbon source strata in the Sichuan Basin. Among them, the Ordovician Wufeng Formation—Silurian Longmaxi Formation marine shale are the most favorable strata for exploration and development with stable distribution and excellent quality (He et al., 2023). The burial depth of deep shale gas reservoirs in the southern Sichuan Basin ranges from 3500 to 4500 meters. These reservoirs are characterized by very complex geological conditions, including developed faults and fractures and high in-situ horizontal stresses.