A Complex Fracture Network Modeling Method Based on Dimensionality Enhancement of Microseismic Event Location Information

Abstract

The modeling method of hydraulic fracturing fracture network combined with microseismic monitoring is currently a hot research topic. In the process of hydraulic fracturing production, previous studies have established a fracture model after fracturing based on the recorded source coordinates, earthquake time, and moment magnitude throughout the entire fracturing cycle, in order to evaluate the fracturing results. However, in the process of reservoir fracturing transformation, real-time evaluation of fracturing effect and provision of fracturing guidance are required. The method of establishing fracture models through long-term data collection is obviously not applicable. Nevertheless, existing research lacks efficient and direct 3D fracture network modeling methods based on microseismic events. To address these challenges, this study introduces a novel three-dimensional fracture network model reconstruction process, DEFME (Dimensionality Enhancement and Fracture Modeling of Microseismic Event Location Information), specifically tailored for datasets containing only the source coordinate information of microseismic events. This innovative process initially incorporates the improved DB-RANSAC (Density-Based Random Sample Consensus) method, introducing new regional microseismic event normal vector constraint information. It transforms the conventional DBSCAN(Density-Based Spatial Clustering of Applications with Noise) clustering algorithm into the NC-DBSCAN (Normal Vector Constraint-DBSCAN) method, combining normal vector constraints with density constraints for microseismic event point clustering. Finally, the Alpha-shape method is employed to extract contour information for each fracture, constructing a three-dimensional plane geometric model of the fracture. To validate the efficacy of the proposed processing workflow, synthetic data and public dataset are utilized. The corresponding results indicate that DEFME has successfully overcome noise interference and efficiently and accurately established a three-dimensional fracture network model based on microseismic events.

Keywords

• Microseismic monitoring
• NC-DBSCAN
• DB-RANSAC
• hydraulic fracturing
• fracture modeling