中国叠合含油气盆地石油地质基本特征与研究方法

中国大陆显生宙以来的多旋回发展历史使海相一海陆过渡相古生界与陆相中、新生界叠置，形成叠合含油气盆地。按不同阶段的叠合样式将叠合盆地分为继承、延变与改造三大类，其油气资源潜力、分布与使用的勘探思路和技术不同。叠合盆地有些石油地质现象超出了已有石油地质理论范围，深层和超压条件下的生、排烃机理与成藏、油气分布不完全遵从“源控论”，“退火”背景下超晚期成藏，大油气田分布不遵从已有模式，深层与早成藏、晚埋藏和次生作用有关的储集体的物性好于按常理的预测。对叠合盆地油气藏形成与分布的认识应坚持以过程重建为主线的综合研究，选择勘探技术应按不同阶段和需要而有不同侧重，并配套使用，求得勘探高效益。图8表1参20关量词：墨合盒地；复合合油气系统；继承；延变5超晚期成藏5勘探思路；技术

Basic features of petroleum geology in the superimposed petroliferous basins of China and their research methodologies

The continental plates of China have undergone a long history of several geologic evolution cycles since Phanerozoic, which have caused the formation of superimposed sedimentary basins characterized with the terrestrial facies of Mesozoic to Cenozoic sitting upon the marine and marine to terrestrial facies of Paleozoic sequence. The superimposed basins can be divided into three basic types according to their development features occurring during different geological ages, namely: the successive, gradually transformed, and transformed types. Specific petroleum exploration concepts and technology are generated in this paper to determine the potential petroleum distribution, because some of the petroleum geologic phenomena of the superimposed basins has exceeded the range of present petroleum geology theory. Under deeply buried and overpressured conditions, the mechanism of hydrocarbon generation and expulsion, the formation of traps and the distribution of hydrocarbons are not confined or explained by over late reservoir formation under source kitchen control's theory and annealing geological background, hence the distribution of large oilfields does not follow the existed model which called source kitchen control's theory. The properties of reservoirs at the deep interval with the features of early formation of hydrocarbon accumulation and late burial as well as the formation of secondary pores, fractures and dissolved cave and cavern are much better than that we predicted on the basis of common theory of petroleum geology. To understand the formation and distribution of hydrocarbon accumulations in superimposed basins requires integrated research that takes the process oriented study as the key component. The exploration technologies should be chosen according the stage of exploration and the required results, and should be used in a complementary manner. In this way we can achieve difficult objectives with the best efficiency.