渤海湾盆地沧东凹陷南皮斜坡地质特征与油气成藏  

Geological characteristics and hydrocarbon accumulation of Nanpi Slope in the Cangdong Sag,Bohai Bay Basin

作　　者：周立宏[1] 时筱淞[2] 官全胜[2] 杨朋[2] 林伶[2] 吴佳朋 

机构地区：[1]中国石油大港油田分公司,天津300280 [2]大港油田勘探开发研究院,天津300280

出　　处：《天然气地球科学》2017年第9期1289-1297,共9页Natural Gas Geoscience

基　　金：中国石油天然气集团重大科技专项"大港油区大油气田勘探开发关键技术研究"(编号:2014E-06-03)资助

摘　　要：随着沧东凹陷正向构造带油气藏勘探程度的不断提高,成藏区带规模发现遇到瓶颈,勘探思路必须由构造油气藏勘探向斜坡连续性油气藏勘探转变。通过对沧东凹陷南皮斜坡精细构造解释、沉积微相划分、烃源岩特征及区域控砂控藏机制的分析,获得南皮斜坡地质特征与油气成藏模式的认识。研究表明,南皮斜坡为宽缓继承性斜坡,构造呈现高、中、低斜坡三分性特点,古近系孔店组二段(孔二段Ek_2)发育辫状河三角洲沉积,孔店组一段(孔一段Ek_1)底部发育浅水三角洲、上部发育冲积扇沉积,有利砂体大面积发育,孔二段发育好—很好烃源岩,生烃强度大。以构造、砂体、烃源岩及已知油藏匹配,形成自源成藏、它源成藏两大成藏组合系统,并构建孔二段有效生油岩范围内,中斜坡孔二段主砂体区常规油藏聚集,低斜坡远端细粒沉积岩类与油页岩叠合形成致密油,含油气系统范围内常规油与致密油叠加连片,形成"连续性成藏"油气成藏模式;孔一段受孔二段有效烃源岩控制下,形成"底部砂组近源大面积充注、上部继承性断裂网状沟通"的复合聚油模式。With increasing exploration degree of hydrocarbon reservoirs in the forward structural belt, the large-scale discovery of Tibet entered a bottleneck.The exploration idea must change from structural reser- voir exploration to slope continuous reservoir exploration.By analyzing fine structure interpretation, sedi- mentary microfacies division, source rock characteristics and regional sand control mechanism of Nanpi Slope in the Cangdong Sag,we get the understanding of the geological features of the Nanpi Slope and the model of oil and gas accumulation.The study shows that the Nanpi Slope is a broad and gentle inherited slope,and the structure shows three characteristics of high, medium and low slopes.The Ek z formation de- velops Braided River Delta in Paleogene,shallow delta is developed at the bottom of Ek~ formation,and al- luvial fan sedimentary environment is developed in the upper part.The environment development is favora- ble for large areas of sand bodies.High quality source rocks developed in the Ek2 formation,with high hy- drocarbon generating intensity.Based on the matching of structure,sand body, source rock and known res- ervoir, two reservoir forming combination systems of self-source accumulation and other source accumula- tion are formed.In the effective oil source rock range,the conventional reservoir accumulated in the middle slope main sand body area, the low slope and the distal fine-grained sedimentary rock overlap with oil shale to form tight oil in Ek2.In oil and gas system, conventional oil and tight oil overlap to form a model of con- tinuous accumulation.Under the control of Ek2 effective hydrocarbon source rocks,Ekl formed a composite oil accumulation model of ＂bottom sand group, near source, large area filling, upper succession fault and network communication＂.

关 键 词：南皮斜坡 构造油藏 自源成藏 连续性成藏 

分 类 号：TE122.2[石油与天然气工程—油气勘探]