摘要
塔里木盆地塔中地区奥陶系埋藏深度普遍超过4 500 m,油气具有平面上广泛分布、垂向上多层系叠加分布特征,这与油气输导体系类型和空间配置组合关系密切联系。运用地质剖析与地化参数示踪分析相结合方法,对塔中地区深层奥陶系碳酸盐岩输导体系类型及其控藏作用进行了研究。结果表明:塔中地区奥陶系输导通道包括断层、不整合面及渗透性输导层,但各自作用差异明显。断层是垂向沟通油源的高效通道,控制着油气的纵向分布范围和规模,随着与断层距离的增加,油气藏规模和产能逐渐变小;不整合面是侧向分配油气的通道,控制了油气的平面分布范围,已发现油气藏主要分布在不整合范围内,且距不整合面越近,产能越高;渗透性输导层既是油气侧向运移的通道,又是油气储集空间,已发现油气主要分布在孔洞和洞穴型储层内。断裂、不整合面及渗透性输导层构成的"垂向通源-侧向分配-高孔汇聚"型输导格架,控制了寒武系—奥陶系烃源岩生成的油气沿断裂向上运移后在塔中地区奥陶系目的层内向两侧呈"T"字形输导分配,并优先聚集于次生孔隙发育的碳酸盐岩储集层内。
Ordovician burial depth of Tazhong area in Tarim Basin is generally above 4 500 m.Hydrocarbons are characterized by horizontally wide distribution and vertically superimposed multi-layer system which has a close relationship with hydrocarbon transport system,as well as space configuration and combination.With a method of combining geologic analysis and geochemical parameters tracer analysis,this study is focused on the types of deep Ordovician carbonate transport system,and their control on the reservoir.Results show that Ordovician migration pathways include faults,unconformable surface and permeable carrier beds,but there are obvious differences in their effects.Fault is the efficient pathway for vertical migration of oil and gas,and controls vertical distribution scope and scale of hydrocarbons.With increase of distance to fault,scale and yield of hydrocarbon reservoir is gradually decreased.The unconformable surface is the pathway for lateral migration of oil and gas,and controls planar distribution scope of hydrocarbons.Discovered hydrocarbon reservoir is mainly distributed within range of unconformable surface.If distance to unconformable surface becomes smaller,hydrocarbon yield will be higher.The permeable carrier bed is not only the pathway for lateral migration of oil and gas,but also the important hydrocarbon reservoir space.It is discovered that hydrocarbons are mainly stored in cavity-type and cave-type reservoirs.The transport system is characterized by vertical connectivity of hydrocarbon,lateral distribution,and high porosity convergence,consisting of fault,unconformity surface and permeable carrier bed.Under control of transport system,oil and gas generated from Cambrian-Ordovician source rock migrates upward along faults,exhibiting T-shape migration and distribution toward both sides of Ordovician strata in Tazhong area,and then initially accumulate in the reservoir with developed secondary pores.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2015年第S2期51-59,共9页
Acta Petrolei Sinica
基金
国家重点基础研究发展计划(973)项目(2011CB201100)
北京高等学校青年英才计划项目(YETP0668)资助
关键词
塔里木盆地
塔中地区
深层
奥陶系碳酸盐岩
油气输导体系
油气运聚成藏
Tarim Basin
Tazhong area
deep layer
Ordovician carbonate rock
hydrocarbon transport system
hydrocarbon migration and accumulation
