Prospects for ultra-deep oil and gas in the “deep burial and high pressure” Tarim Basin

Ultra-deep oil and gas exploration technology is developing, and the thermal evolution of source rocks under high pressure in the Tarim Basin has become the focus of ultra-deep oil and gas resource evaluation and hydrocarbon generation theory research. Simulated hydrocarbon generation from source rocks under high temperature and pressure, combined with the geological conditions of “deep burial and high pressure” of the Shuntuoguole Uplift in the Tarim Basin, a study was carried out on the hydrocarbon generation, evolution and retardation under high pressure of marine source rocks in the Tarim Basin. Ever since the Yanshan period, the Cambrian source rocks still have geological conditions for generating high-maturity liquid hydrocarbon in the Shuntuoguole Uplift. The boundary conditions for thermal evolution retardation include: ①Long-term stable closed system; ②Source rocks deeper than 6 500 m with the fluid pressure above 60 MPa, and a low temperature with a gradient less than 20 ℃/km in the later period; ③Marine source rocks with type I and type Ⅱ₁ kerogen. The ultra-deep Cambrian marine source rocks in the Tarim Basin are mainly type I and type Ⅱ₁ kerogen, and the degree of inhibition is more obvious under high pressure. The scope and potential of the oil generation window are much higher than the traditional theoretical value. Therefore, the prospect for ultra-deep oil and gas exploration is considerable.