Abstract:
Due to the complex accumulation conditions and varied reservoir properties of tight oil and gas in continental fault basins, it is very difficult to carry out large-scale development. According to the geological, geochemical, experimental analysis and production test data of Bohai Bay Basin, the paper compares the characteristics of tight reservoir in depression basins at home and abroad, and comprehensively analyzes the accumulation conditions and features of tight oil and gas in fault basins. The results show that the organic-rich shale in the hydrocarbon generation sag of fault basins is characterized by large thickness, high abundance of organic matter, and wide maturity evolution range. The shale with complex compositions are interbedded with the tight reservoir of different lithology frequently to form rich self-generated and self-stored or proximate-accumulated tight oil-gas resources. The tight reservoir can be classified into four types, namely tight clastic rocks, carbonate rocks, volcanic rocks and shale in terms of lithology, among which the carbonate rock reservoir has the best accumulation conditions, thus much easier to exploit. The structural fracture developed areas in the shale formation near the faults also have good reservoir-forming conditions for exploration.