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通过对我国西北地区侏罗系一些含煤盆地石油的形成、成烃机理、煤沼沉积环境及其演化的研究后发现,一些形成工业性煤成油田盆地的煤沼沉积环境演化有其一定的规律性,即在具完整湖平面变化旋回层序的水进序列中形成的含煤建造更有利于煤成油藏的形成含煤建造上覆的湖相泥岩,既可以是油源岩,同时,也是良好的盖层.根据西北侏罗系煤沼沉积环境演化特征,可将其划分为3种煤沼沉积环境演化类型:(1)发育在冲积体系和河流体系中的含煤建造,如祁连和贺兰山地区的一些山间聚煤盆地;(2)含煤建造(组)的上下没有发育典型的湖相地层,或含煤建造的直接上覆没有典型的湖相地层的发育,也就是说,除煤层外,很少有泥灰岩、炭质泥岩、油页岩等湖相地层的形成.典型的如鄂尔多斯盆地.该盆地延安组含煤建造的上覆是直罗组,该组由一套冲积体系组成;(3)煤沼发育的后期都发育有典型的湖相
Through the study on the formation and hydrocarbon generation mechanism of some Jurassic coal-bearing basins in northwestern China and the sedimentary environment and evolution of coal and marsh, it has been found that some of the coal-marsh sedimentary environments evolved in some industrial coal-formed oilfields have their own certain The regularity, that is, the coal-bearing formation formed in the sequence of water with intact labyrinthine changes in sequence is more favorable to the formation of coal-bearing reservoirs. The formation of coal-bearing lacustrine mudstones can be either source rocks or both , Which is also a good caprock.According to the sedimentary environment evolution characteristics of the Jurassic coal and marsh in Northwest China, it can be divided into three types of coal and marsh sedimentary environment evolution: (1) coal-bearing construction in alluvial and river systems, such as Qilian and Helan Mountain areas; (2) there is no typical lacustrine strata developed above and below the coal-bearing construction (group), or no typical lacustrine strata have been formed in the direct overburden of the coal-bearing formations In other words, except for the coal seam, there are few lacustrine formations such as marl, carbonaceous mudstone, oil shale, etc. Typical examples are the Ordos Basin, where the overlying coal seam of the Yan’an Formation in this basin is Zhiluo Formation, Group consists of a system of alluvial systems; (3) coal mines The late development are typical of lacustrine