石油成藏过程中的地球化学变化及控制因素的综合评述

油藏内原油的地球化学特征除了受源岩有机相、成熟度和沉积环境的制约外，还受到石油在成藏过程和成藏后所经历的各种地质-地球化学因素的影响。分析了石油在成藏过程中，族组份、生物标志物组成以及稳定碳同位素组成等方面发生的地球化学变化，综合评述了生物降解作用和水洗作用、流体-岩石相互作用(包括地色层作用)、热化学硫还原作用、石油运移过程中的相控分馏作用、不同期次充注的原油的混合作用及浸析作用等因素对石油地球化学特征的影响。

Geochemical Alteration of Hydrocarbon Compositions During Migration and Accumulation and Its Controlling Factors

Geochemical characteristics of hydrocarbon in reservoir are not only controlled by the organic-phase, maturity and sedimentary environment of source rock, but also affected by many other geological and geochemical factors including biodegradation, water washing, fluid/rock interaction and geochromatography (during hydrocarbon migration and accumulation), phase-controlling molecular fractionation (during hydrocarbon migration and entrapment), thermal alteration, multiple charge and mixed of petroleum, dissemination (reservoir overprinting, solubiliza-tion) and thermochemistry sulfate reduction, etc. , during petroleum migration and accumulation. In this papar, the influences of the geological and geochemical factors on the geochemical characteristics of petroleum, such as biodegradation and water washing, fluid/rock interaction and geochromatography, phase-controlling molecular fractionation, thermal alteration, multiple charge and mixed of petroleum,dissemination and thermochemical sulfate reduction, etc. are disccessed.