Multi-scale fracture prediction of shale oil reservoir driven by the combination of post-stack and pre-stack seismic data
Systematic characterization of natural fractures across various scales and types plays a pivotal role in identifying high-quality reservoirs and optimizing development outcomes.Establishing a reliable multi-scale fracture model serves as a critical foundation for enhancing the drilling efficiency in shale oil reservoirs.The key challenge lies in accurately predicting the spatial distribution of small-scale fractures and effectively guiding drilling and fracturing operations.Traditionally,fracture prediction methods based on seismic attributes tend to emphasize individual single-scale fractures.However,the mathematical independence of different fracture attributes poses a significant obstacle when identifying integrated fracture systems.To address this,we propose an improved approach for estimating full-scale fracture systems.The key innovation involves determining the development probability of small-scale fractures using an optimized anisotropic ant colony fracture identification algorithm.By integrating this small-scale fracture probability with the likelihood of large-scale faults generated through conventional ant tracking,our method achieves comprehensive full-scale fracture sensing.The detailed property analysis process shows that the azimuthal anisotropy can accurately characterize microscopic fractures.Based on this,we integrate the fracture density and fracture orientation obtained from the anisotropy analysis into each stage of ant colony tracing fractures,which can improve the search intensity of fracture dense areas while achieving accurate portrayal of the development direction of small fracture breaks.The application cases for shale reservoirs demonstrate that the full-scale fracture system obtained according to the improved scheme can simultaneously characterize the distribution of large-scale faults,small fractures and fracture fragmentation zones.The imaging logging in the study area further validate the accuracy and reliability of predicting the direction of small-scale fractures,which can provide theoretical guidance for the development and deployment of shale oil horizontal wells.
万方数据
维普
