浅谈沉积盆地超压形成机理及对有机质演化的影响

The formation mechanism of overpressure in sedimentary basins and its influence on the evolution of organic matter

通过文献调研对沉积盆地内超压的成因、超压对有机质演化的影响有了系统的认识和理解。不均衡压实、生烃作用、水热增压、黏土矿物脱水以及构造应力等都可以形成超压,其中构造挤压、不均衡压实和生烃作用是超压产生的主要机制。研究表明,超压对有机质演化总是具有抑制作用,但是在不同的盆地、同一盆地的不同构造单元甚至是同一构造单元的不同层位之间的抑制作用往往存在明显的差异性。造成这些差异性的原因是多方面的,剩余压力的大小、源岩类型、超压发育时的有机质成熟度、超压持续时间、以及超压系统内地层水的物理化学性质都会对超压的作用结果产生重要的影响。

Through literature research,this paper has systematic understanding of the causes of overpressured in sedimentary basins and the influence of overpressured on the evolution of organic matter.disequilibrium compaction,hydrocarbon generation,hydrothermal pressurization,dehydration of clay minerals,and tectonic stress can all form overpressured.Among them,disequilibrium compaction and hydrocarbon generation are the main mechanisms of overpressured generation.Studies have shown that overpressured has always inhibited the evolution of organic matter,but there are often significant differences in the inhibition between different basins,different tectonic units of the same basin,and even different layers of the same tectonic unit.The reasons for these differences are multifaceted.The magnitude of surplus pressure,the type of source rock,the organic matter maturity during overpressure development,the duration of overpressured,and the physicochemical properties of formation water in an overpressure system are have important effects in an overpressured system.