Dynamic evolution mechanism of the fracturing fracture system—Enlightenments from hydraulic fracturing physical experiments and finite element numerical simulation

Abstract

This study aims to elucidate the dynamic evolution mechanism of the fracturing fracture system during the exploration and development of complex oil and gas reservoirs. By integrating methods of rock mechanical testing, logging calculation, and seismic inversion technology, we obtained the current in-situ stress characteristics of a single well and rock mechanical parameters. Simultaneously, significant controlling factors of rock mechanical properties were analyzed. Subsequently, by coupling hydraulic fracturing physical experiments with finite element numerical simulation, three different fracturing models were configured: single-cluster, double-cluster, and triple-cluster perforations. Combined with acoustic emission technology, the fracture initiation mode and evolution characteristics during the loading process were determined. The results indicate the following findings: (1) The extension direction and length of the fracture are significantly controlled by the direction of the maximum horizontal principal stress. (2) Areas with poor cementation and compactness exhibit complex fracture morphology, prone to generating network fractures. (3) The interlayer development of fracturing fractures is controlled by the strata occurrence. (4) Increasing the displacement of fracturing fluid enlarges the fracturing fracture length and height. This research provides theoretical support and effective guidance for hydraulic fracturing design in tight oil and gas reservoirs.