柳屯洼陷盐间超压泥岩裂缝稠油油藏成藏模式研究

Research on formation mechanism and oil accumulation mode of inter-salt fractured mudstone with high pressure in Liutun Sag

柳屯洼陷盐间高温高压泥岩裂缝稠油油藏是一种非常特殊的油气藏类型,盐间的泥岩具有有机质丰度高、类型好的特点,由于成熟度较低,生成的油气胶质沥青质含量较高,导致油质较稠。同时,受构造及超压的影响,盐间泥岩裂缝发育,烃源岩生成的油气通过幕式排烃进入泥岩裂缝储层中,然后顺层沿泥岩裂缝带向上运移成藏,由于盐层的封堵能力较强,泥岩裂缝油藏总体上为"自生自储"油藏。

Inter-salt fractured mudstone heavy oil reservoir with high temperature and pressure in Liutun Sub-sag is special with its inter-salt mudstone featuring high organic matter abundance and good properties.While the oil in this reservoir is heavy due to the high content of colloid and asphaltine within thanks to low maturity of formation.The structure and super pressure of inter-salt mudstone gear up the growth of fractures,then the oil and gas generated in source rocks migrate into mudstone fractured reservoir by episodic expulsion and then go upwards along fracture area and accumulate.This kind of oil reservoir is self-generating and self-preserving as a whole for its excellent performance in sealing and plugging.