Research Progress on Prediction Methods of Coupling Natural and Artificial Fractures

Abstract

AbstractThere are both differences and relations between natural fractures and artificial fractures. Natural fracture research is the foundation, while artificial fractures aggravate the complexity of fracture development. The coupling relationship between them is the core of research on unconventional reservoir fractures. Through a large number of domestic and foreign literature surveys, combined with the author’s own practice, this paper systematically analyzes the characteristics and interrelationships of artificial fractures and natural fractures. It is expounded from three aspects: the quantitative prediction method of natural fracture, the detection method of artificial fracture and the coupling relationship between natural fractures and artificial fractures. Firstly, in terms of natural fracture prediction, analyses geological analysis methods, logging interpretation methods, seismic detection methods, nonlinear quantitative predictions and numerical simulation methods of quantitative prediction, and examples of author’s own research, analyzes the effect of fracture prediction, and simulates the influence of natural fracture network on water injection development. Secondly, in the monitoring of artificial fractures, methods such as micro-seismic detection and well test detection are analyzed, and it is pointed out that the artificial fracture network reconstruction volume of the reservoir is the main controlling factor that affects the stimulation effect of reservoirs. Based on the analysis of natural fractures and artificial fractures, the coupling relationship between artificial fractures and natural fractures in the water injection process is studied by applying an example of oilfield water injection development, and it is clear that the dynamic fractures opened during the water injection development are the comprehensive reflection of the two. Finally, according to the latest development of reservoir fracture research, it is proposed that the multi-scale fracture simulation using artificial intelligence technology combined with fracturing fracture simulation is the future development direction of fracture prediction technology.KeywordsNatural fractureArtificial fractureConceptual modelDiscrete fracture network modelCoupling