摘要
应用地球化学、成藏模拟和流体包裹体技术对陆丰凹陷烃源岩及油气成藏特征进行评价和分析。陆丰凹陷古近系存在2套烃源岩,恩平组烃源岩总体成熟度不高,生烃量有限,为次要烃源岩。文昌组烃源岩成熟时间早,生烃规模大,系主力烃源岩。A3洼和A4洼是潜在生烃洼陷。陆丰凹陷原油为典型的陆相原油,其油源岩以文昌组烃源岩为主,恩平组烃源岩贡献较少。研究区分为陆丰南和陆丰北含油气系统,陆丰南含油气系统油源主要来自A3洼文昌组,其次是A4洼;陆丰北含油气系统油源主要来自A3洼文昌组,少量来自A2洼文昌组以及恩平组。陆丰凹陷主要有2期油气充注,第一期充注于中新世中期(12.89~10.05 Ma)前,以低熟液态烃为主;第二期充注始于上新世末期(2.52 Ma)前,以成熟烃类为主。陆丰凹陷油气勘探方向应以深层(文昌组)为主,寻找深层早期形成的构造是该区域下一步勘探的重要目标。
Source rocks and characteristics of hydrocarbon accumulation are evaluated and analyzed by the techniques of applied geochemistry,simulation of petroleum pool-forming and fluid inclusion in Lufeng sag which has two main sets of mature source rock in Paleogene,with Enping Formation as the secondary source rock due to its lower maturity and limited hydrocarbon generation,and Wenchang Formation as the leading source rock due to its maturation and sizable hydrocarbon generation.Subsag A3 and A4 are potential hydrocarbon kitchens.The crude oil belongs to typical continental oil and main originates from the Wenchang Formation source rock,however,Enping Formation has the limited contributions.The study area has two petroleum systems,which are the north and south of Lufeng sag petroleum systems.Crude oil of the south of Lufeng sag petroleum system originates from Wenchang Formation in A3 subsag,secondly,from A4 subsag.Crude oil of north of Lufeng sag petroleum system main originates from A3 subsag Wenchang Formation,and at the same time,a spot of oil originates from A2 subsag Wenchang Formation and Enping Formation.Lufeng sag has two stages of hydrocarbon charge.The earlier first stage started before in Middle Miocene(12.89~10.05 Ma),with mainly low liquid hydrocarbon.The second stage sated before in Late Pliocene(2.52 Ma),with mainly mature hydrocarbon.In a word,the oil-gas exploration direction should be given priority to the deep region(Wenchang Formation)and the next important target is the early deep structure.
出处
《地球科学前沿（汉斯）》
2019年第3期166-176,共11页
Advances in Geosciences
基金
国家科技重大专项(项目编号:2011ZX05030-002-005)。
