关键词: 歧口凹陷, 含油气系统, 亚含油气系统, 资源评价

Abstract: The whole logic of hydrocarbon system includes identifying,classifying,depicting and evaluation.Its sole purpose is to correlate between(sub-)hydrocarbon systems and then to select the most prospective one to explore and exploit.This paper,based on the latest conclusions resulting from petroleum geology,basin model and geochemistry,splits the Qikou Sag into two hydrocarbon systems,which are named Sha3(!)and Shal(!).The former can be subdivided into Sha3-E(!) sub-system and Sha3-N(!)sub-system.The overall evaluation,including the source appraisal of(sub-) hydrocarbon system,shows that Qikou Sag has very good expectation:Sha3(!)system should be the highlight of late exploration,especially the Sha3-E(!)sub-system whose pre-Teritary and the others should be focused on.Shal(!)system has good expectation as well.

Key words: Qikou Sag, hydrocarbon system, sub-hydrocarbon system, source appraisal