The shale revolution and basic geological theory problems of shale and tight oil and gas

The shale revolution has weaned the US from its dependence on imported oil and gas to become a net exporter. This paper reviews the history of the shale revolution in the United States, summarizes the characteristics of shale oil and tight oil and gas, analyzes the development status of the shale oil and gas revolution in China, and puts forward the basic geological theory of shale oil and tight oil and gas. The research shows that: (A) The United States has advantages such as good resource endowment, strong scientific and technological innovation ability, huge investment capacity, and strong engineering construction capacity, and has already realized the shale revolution. China’s shale revolution is now under way. (B) Compared with conventional oil and gas, shale oil and tight oil and gas have different accumulation modes and development methods. They have the characteristics of continuous large-area distribution, self-sealing oil and gas accumulations, huge development and production engineering, and the "distributed" characteristics of oil and gas field production can flexibly cope with the characteristics of production reduction and low recovery. (C) Seven conditions need to be met for the further production of shale oil and gas in China: These are(1) Clear resources; (2) Mature horizontal well and fracturing technology; (3) The cost is controllable; (4) The engineering space of enhanced oil recovery in the late stage is large; (5) Meet environmental requirements; (6) Adequate capital investment; (7) Strong engineering construction ability. (D) The whole oil and gas system has a sequence of conventional oil and gas, tight oil and gas and shale oil and gas. Shale oil and gas and tight oil and gas reservoirs have the basic characteristics of tight reservoirs, complex fluid composition and phase state, and diverse reservoir driving modes, and we are faced with the problem of unclear reservoir geological and flow models. It is necessary to carry out further theoretical research of the whole oil and gas system, and vigorously develop sweet spot evaluation technology and fracturing technology.