渤南洼陷沙四上亚段储层异常高孔带及优质储层成因机制  

Anomalous High Porosity Zone and Formation Mechanism of High Quality Reservoir of Es_4~s in Bonan Sag

作　　者：邱隆伟[1] 徐宁宁 刘魁元[2] 杨生超 解超 单宝杰[2] 武玉玺 

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266555 [2]中国石化胜利油田分公司河口采油厂,山东东营257200 [3]中国石化胜利油田分公司东辛采油厂地质所,山东东营257094

出　　处：《天然气地球科学》2015年第1期1-12,共12页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:2011ZX05009-002)资助

摘　　要：渤南洼陷沙四上亚段碎屑岩储层约3 000~4 000m的深度范围存在明显的异常高孔带。结合岩心实测物性数据,利用连续深度区间的孔隙度分布图和建立的孔隙度—深度拟合曲线确定异常高孔隙带识别标准和分布范围。综合铸体薄片数据、扫描电镜分析、地层压力数据等,从成岩溶蚀、异常高压和早期油气充注等方面阐释异常高孔带成因,并结合沉积微相、岩相和断裂发育等总结相对优质储层成因机制。研究认为储层异常高孔带的发育得益于异常高压对孔隙的保护、中成岩A期有机质低熟阶段的有机酸溶蚀增孔作用和早期烃类充注的保孔作用;异常高孔带的发育、原始沉积因素如优势沉积微相（扇三角洲前缘水下分流河道和分流河口砂坝等）和刚性颗粒（石英、长石和变质岩岩屑等）含量相对高值的中粗粒砂岩以及断裂的发育组成相对优质储层形成的主要条件。The research indicated a distinct anomalous high porosity zone of Ess4 in 3 000-4 000 mdepth range in Bonan Sag.Combined with core physical property data,the paper identified normal and abnormal porosity distribution,utilizing the distribution of reservoir porosity in continuous interval depth and curves of porosity changing with depth.Integrated with thin section data,scanning electron microscopy analysis and formation pressure data,the paper explained reasons for high porosity and permeability zone by aspects of diagenetic erosion,abnormal high pressure and hydrocarbon charging at early stage.Combined with microfacies,lithofacies,development fracture,the paper discussed the genetic mechanism of high quality reservoir.The result suggests that anomalous high porosity zone in reservoir was benefited by protection of overpressure,organic acid dissolution and hydrocarbon emplacement at early stage.The main conditions of high quality reservoir were as followings：development of anomalous high porosity zone;original deposition factors such as advantage facies（underwater distribution channel and mouth bar in fan delta front）,relatively high proportion of mid-coarse rigid particles（quartz,feldspar and metamorphic fragments）and fracture development.

关 键 词：渤南洼陷 沙四上亚段 异常高孔带 优质储层 

分 类 号：TE122.23[石油与天然气工程—油气勘探]