摘要
低勘探程度盆地,特别是在海域,钻井稀少且一般位于构造高部位,而盆地中心烃源岩埋藏深,又无钻井揭示,如何评价盆地中心烃源岩的演化程度和排烃历史是盆地或凹陷评价的关键问题。该文以东海椒江凹陷为例,从凹陷边缘或构造高部位具备实测温度和镜质体反射率(Ro)资料的钻井出发,利用正演模拟方法,恢复椒江凹陷岩石圈结构及其演化史,进而模拟整个凹陷古新统烃源岩的热演化史。研究表明,椒江凹陷古新统烃源岩现今最大Ro达到2.8%,为过成熟状态。凹陷总排油量略多于排气量,总排烃量为33×108m3油当量,主要的排烃期在中新世之前。下一步勘探应在凹陷中部凸起带选择圈闭条件好、且形成于中新世之前的目标进行钻探。
In low-exploration basins,especially offshore ones,wells are rare and usually locate in the higher positions.The source rocks in basin centers are buried deeply and are not drilled.Therefore,it is the key for basin/sag evaluation to study the thermal evolution and hydrocarbon expulsion history of source rocks in basin centers.Case studies have been carried out in the Jiaojiang Sag of the East China Sea Basin.Based on the measured temperature and Ro data collected from wells locating in the sag edge or the higher positions,by means of forward modeling method,the lithosphere structure and thermal history of the Jiaojiang Sag have been recovered,and the thermal history of Paleocene source rocks in the whole sag have been modeled.The results show that the maximum Ro of Paleocene source rocks in the sag is 2.8%,indicating over-mature state.The total amount of oil expulsion is a little bit more than that of gas expulsion,and the amount of hydrocarbon expulsion is 33×108 m3 oil equivalent.Hydrocarbon expulsion mainly took place before Miocene.In the future exploration,the prospects with good traps and were formed before Miocene in the central uplifts should be focused on.
出处
《石油实验地质》
CAS
CSCD
北大核心
2012年第3期319-324,329,共7页
Petroleum Geology & Experiment
基金
国家重大科技专项(2008ZX05023-01)资助
关键词
烃源岩热演化
正演模拟
岩石圈结构
低勘探程度盆地
东海椒江凹陷
thermal evolution of source rock
forward modeling
lithosphere structure
low-exploration basin
Jiaojiang Sag of East China Sea Basin
