南堡凹陷断裂对油气运聚成藏的控制作用  

Control of faults on hydrocarbon migration and accumulation in the Nanpu Sag

作　　者：孙永河[1] 赵博[1] 董月霞[2] 郑晓凤[2] 胡明[1] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]中国石油冀东油田分公司,河北唐山063004

出　　处：《石油与天然气地质》2013年第4期540-549,共10页Oil & Gas Geology

基　　金：国家自然科学基金项目(41202146);国家基础研究发展计划(“973”计划)项目(2012CB723102)

摘　　要：为了揭示南堡凹陷断裂对油气分布规律的影响,以断裂为主线,结合成藏地质条件,系统研究了断裂对油气运聚成藏与分布的控制作用,并通过建立断裂输导模式指出了有利勘探方向。研究表明,地垒或半地垒、背斜负花状组合和背斜断阶等正向局部构造是油气富集的有利部位。东营组二段盖层断接厚度小于90～95 m时,断裂对盖层的破坏程度大,油气可跨越盖层在中、浅层聚集成藏;且盖层段断裂密度越大,油气穿越盖层富集的层位越浅。Ⅴ型和Ⅵ型断裂为油源断层,且两条或多条交叉断裂是油气垂向运移的优势通道,并选择砂地比大于20%的储层中发生断储分流运移。充注到断层圈闭中的油气在断层古、今封闭性均较强下才能大规模聚集和保存。与Ⅰ型、Ⅱ型和Ⅳ型断裂相关且高砂地比储层的正向局部构造,以及与Ⅴ型和Ⅵ型断裂相关且东营组二段盖层断接厚度大于90～95 m的高砂地比储层的正向局部构造,是深层油气的有利勘探方向。与Ⅴ型和Ⅵ型断裂相关且东营组二段盖层断接厚度小于90～95 m、高砂地比储层以及断层侧向封闭性好的正向局部构造是中、浅层油气的有利勘探方向。This paper systematically studies the control of faults on hydrocarbon migration and accumulation in Nanpu sag and predicts favorable exploration targets through establishing fault transporting models. Research shows that positive local structures such as horst/half horst, negative flower structure combinations of anticline, fault terrace belt of anticline and so on are the favorable for hydrocarbon accumulation. When the juxtaposition thickness of faults in Ed2 cap rock is less than 90 -95 m, hydrocarbons can penetrate the cap rock and accumulate in the middle-shallow layer. The greater the fault density is, the shallower the hydrocarbon accumulation is. Type Ⅴ and Ⅵ faults are source rock-rooted faults and two or more intersected faults are the preponderant pathways of vertical hydrocarbon migration, and some hydrocarbons may mi- grate along reservoirs with a net-to-gross ratio of over 20 %. The hydrocarbons charging into the fault traps can accumulate and be preserved in large scale only when both the palaeo and current sealing ability of faults are strong enough. Favora- ble deep exploration targets include the local positive structures related with type Ⅰ , Ⅱ and Ⅳ faults and reservoirs with high net-to-gross ratio as well as local positive structures related with type V and VI faults and reservoirs having a juxta- position thickness of Ed2 cap rock over 90 - 95 m and high net-to-gross ratio. While the shallow-to-moderate favorable ex- ploration targets include positive local structures related with type V and Ⅵ faults and reservoirs having a juxtaposition thickness of Ed2 cap rock less than 90 -95 m and high net-to-gross ratio as well as that with good lateral fault sealing ability.

关 键 词：砂地比 断接厚度 断裂组合 正向局部构造 断层侧向封闭性 油气富集 南堡凹陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探]