准噶尔盆地西北部地层压力演化与油气成藏有利动力条件研究

准噶尔盆地西北部发育异常高压, 异常高压是油气垂向运移的重要动力条件, 目前已经在超压带上发现大量高压油气藏。为了揭示现今地层压力特征, 恢复成藏期古压力演化特征。利用测井方法和2D盆地模拟技术, 得到超压的分布和演化特征, 并讨论了超压对油气运移的影响。结果表明, 研究区单井地层压力结构可以分为三类; 由古至今, 各地层超压逐渐变大, 超压由浅部地层向深部地层逐渐变大; 各时期平面上超压分布呈规律性变化, 整体上是由西北部向东南部逐渐增大; 超压的分布和演化成为油气垂向运移有利动力条件, 对研究区高压油气藏的形成具有重要的意义。

Study on the Formation Pressure Evolution and Favorable Dynamic Conditions of Oil and Gas Accumulation in Northwest Junggar Basin

Abnormal high pressure has developed in Northwest Junggar Basin, and it is an important dynamic condition for the vertical migration of oil and gas. At present, many overpressure reservoirs have been found in the overpressure zone. This study aimed to reveal the characteristics of present formation pressure and restore the evolution characteristics of paleopressure during the reservoir forming period. Distribution and evolution characteristics of overpressure were obtained using the logging method and 2D basin simulation technology, and the influence of overpressure on oil and gas migration was discussed. The results showed that the formation pressure structures of single wells in the study area could be divided into three types. From ancient times to the present, the overpressure of each formation gradually increased, and it gradually increased from shallow formations to deep formations. The distribution of overpressure changed regularly in each period, and gradually increased from northwest to southeast; the distribution and evolution of overpressure is a favorable dynamic condition for vertical migration of oil and gas, which is of great significance to the formation of high-pressure oil and gas reservoirs in the study area.