摘要
柴达木盆地西部干柴沟地区历经60余年勘探未获重大油气发现。2019年以来,通过强化山地三维地震勘探技术攻关和深化高原咸化湖相混积型碳酸盐岩成储、成藏研究,油气勘探终获突破,发现了古近系下干柴沟组构造油气藏,同时英雄岭页岩油和湖相碳酸盐岩岩性油气藏勘探也展现出良好前景。研究成果主要得益于以下几点:①高品质三维地震资料揭示干柴沟地下构造形态,发现东翼发育断背斜,为油气聚集提供了有利圈闭条件;②大面积咸化湖相混积碳酸盐岩具备储集能力,碎屑岩、湖相碳酸盐岩和膏盐岩层在纵、横向上均呈有序分布,构成了良好的生-储-盖组合;③基于全油气系统理论,认为研究区常规油气(源外)和非常规油气(源内)立体成藏。剖析干柴沟地区油气勘探历程发现:①地震勘探技术进步是干柴沟复杂构造区地下构造圈闭得以落实和油气地质特征得以揭示的基础;②干旱咸化湖盆发育的大面积混积碳酸盐岩不仅是烃源岩而且具备储集能力,这一认识拓展了勘探领域,是勘探取得突破的关键;③全油气系统理论的引入,推动油气勘探向源内拓展,揭示了英雄岭页岩油的良好勘探前景。
No significant hydrocarbon exploration discoveries were achieved for over 60 years of efforts,and breakthroughs have ultimately been made since 2019 when seismic survey targeting mountainous regions was performed and study on the formation of and hydrocarbon accumulation in mixed siliciclastic-carbonate reservoirs developed in plateau salinized lacustrine environment went further.The discovery of structural reservoirs located in the Lower Ganchaigou Formation of the Paleogene,along with great potentials shown in the exploration and development of Yingxiongling shale oil and lacustrine carbonate lithological reservoirs in this area,can be attributed to the following factors.First,high-quality 3D seismic data serve to reveal the underground structure geometry in the Ganchaigou area,where a faulted anticline favorable for hydrocarbon accumulation as a trap is detected in the east;Second,large-scale mixed carbonate rocks of salinized lacustrine facies have storage capacity,while clastic rocks,lacustrine carbonate rocks and gypsolyte are well-aligned both laterally and vertically,thus being of a good source rock-reservoir-caprock assemblage as a whole;Third,both conventional(out of source rocks)and unconventional(within source rocks)hydrocarbon are generated and accumulate as a total petroleum system(TPS)in the study area.In investigating the exploration process in the study area,we confirm that the progress in seismic exploration technology lays a solid foundation for the discovery of the complex structural trap underground and its petroleum geological characteristics.The mixed carbonate rocks developed in large scale in the dry salinized lacustrine environment function as both source rocks and reservoirs,a finding that has extended our understanding in exploration and been a key in fulfilling the breakthroughs.The adoption of the TPS concept serves to push hydrocarbon exploration to go further into the source rocks while revealing the great potentials of Yingxiongling shale oil to be developed.
作者
陈琰
张永庶
徐兆辉
姜营海
朱超
张静
张彩燕
CHEN Yan;ZHANG Yongshu;XU Zhaohui;JIANG Yinghai;ZHU Chao;ZHANG Jing;ZHANG Caiyan(Qinghai Oil Field Branch,PetroChina,Dunhuang,Gansu 736202,China;Qinghai Provincial Key Laboratory of Plateau Saline-Lacustrine Basinal Oil&Gas Geology,Dunhuang,Gansu 736202,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Hangzhou Research Institute of Geology,PetroChina,Hangzhou,Zhejiang 310023,China)
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2024年第4期1018-1031,共14页
Oil & Gas Geology
关键词
地震勘探
基础地质
全油气系统
非常规油气
干柴沟地区
柴达木盆地
seismic exploration
basic geology
total petroleum system(TPS)
unconventional oil and gas
Ganchaigou area
Qaidam Basin
