东濮凹陷文留地区深层强超压环境下有机质热演化

东濮凹陷文留地区的地层普遍发育超压甚至强超压系统.超压与地层有机质热演化反应过程存在复杂的相关性.深层盐下、盐间地层有机质的热演化受强超压的影响,不同热演化反应过程不同程度地受到抑制作用:镜质体反射率演化正常;烃类裂解以及烃类结构演化在深层强超压作用下受到抑制作用.有机质热演化过程中的超压抑制为深层源岩成烃提供了更为有利的条件,是文留地区深层天然气成藏的主要因素.

Organic Material Thermal Evolution under Overpressure Condition of Wenliu Area of Dongpu Depression

Overpressure or strong overpressure is generally developed in Wenliu area of Dongpu Depression, where the abnormal pressure is in complex correlation with organic material thermal evolution and evolution process. It is found that the organic material under or between salt layers has been affected by thermal evolution to different extent in different processes owning to the sediment overpressure. In the area, the vitrinite reflectance Ro evolution is normal but hydrocarbon cracking and hydrocarbon composition evolution is affected by abnormal pressure or strength overpressure. The overpressure on the organic material of the deep sediment zone provides favorable conditions for the hydrocarbons, the main factor for the hydrocarbon generation and reservoir in Wenliu area.