Research significance, advances and trends on the role of bedding fracture in tight oil accumulation

At present, the research on fractures in petroleum accumulation are limited to tectonic fractures, and mainly deal with conventional petroleum accumulation (including low permeability petroleum accumulation). For tight reservoirs, the studies are also limited to tectonic fractures. Previous investigations revealed that bedding fracture was the most important type because of its common growth and obvious contribution to tight oil accumulation. The time-space matching relationship between bedding fracture opening or closing and petroleum charge is the key of tight oil accumulation. However, research on the effect and role of fractures in tight oil accumulations were very limited, especially on the relationship between bedding fractures and tight oil accumulations as well as the contribution of bedding fractures to tight oil accumulations. This makes bedding fracture opening and closing mechanism and petroleum charge effect an important science question. So, the main geological reasons and the opening and closing mechanism of bedding fractures, the coupling relationship between bedding fracture opening and closing and petroleum charge, and the lower limit of bedding fractures for petroleum charge in tight reservoirs are research trends on tight oil accumulations in the future.