摘要
柴达木盆地西部南区(简称柴西南)勘探程度相对较高,资源潜力较大,是开展岩性油气藏勘探的有利区带,然而,由于近些年来部分钻探井的失利,岩性油气藏富集规律等问题成为制约勘探的关键。通过重新认识该区烃源岩、主力生烃凹陷、古地貌及其控制下的沉积体系发育特征、关键成藏期古构造特征,对比分析古今构造,结合对典型出油气井点的精细解剖,明确指出:柴西南区岩性油气藏富集总体表现为"近凹环凹"特征,主要分布在远源沉积体系控制下的三角洲前缘砂体及滩坝砂储集体中,长期稳定的斜坡区及古今构造高点发生迁移且现今构造为含油构造的迁移带是岩性油气藏的主要聚集区。据此划分了该区岩性油气藏的有利勘探区带,并针对重点区带的部分热点地区构建了油气成藏模式,指明了下一步的勘探方向。
Lithologic reservoir,a special type of subtle reservoir,has become in recent years and will remain in the future one of the important exploration domains.The southwestern Qaidam basin has relatively high exploration maturity and large resource potentials,thus is a favorable area for exploration of lithologic reservoirs.However,the failure of some exploratory wells in recent years indicates that the pattern of hydrocarbon accumulation in lithologic reservoirs has become the key factor restricting the exploration.The source rocks,the major hydrocarbon kitchens,palaeogeomorphology and the sedimentary system under its control,and palaeo-structures in critical hydrocarbon pooling stages are reviewed,a comparative study is performed on the palaeo-structures and modern structures,and the typical discovery wells are analyzed in detail.Lithologic reservoirs in the southwestern Qaidam basin shows that,as a whole,the feature of 'near-sag and circum-sag',and are mainly distributed in delta front and shoal bar sandbodies under the control of distal sedimentary system,long-term stable slope zones,and transport zones where the structural highs of palaeo-structures and modern structures were transported and the modern structures contain oil.Favorable areas for exploration of lithologic reservoirs are recognized and hydrocarbon-pooling models are established for some key exploration areas.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2009年第2期37-41,133,共5页
Natural Gas Industry
基金
中国石油天然气股份有限公司重大科技项目"柴达木盆地油气勘探开发关键技术研究"子课题"柴西地区富油气凹陷圈闭精细评价及钻探目标选择"(编号:07-01Z-01-02)
中国石油股份公司探区重大预探领域与目标选择研究项目子课题"柴达木盆地西南地区石油地质综合研究及有利区带评价与风险目标优选"(编号:2008D-0707-03)的联合资助
关键词
柴达木盆地
西南
岩性油气藏
油气富集规律
成藏模式
勘探区
Qaidam basin,southwest,lithologic reservoir,hydrocarbon enrichment pattern,pooling pattern,exploration area
