摘要
以岩心观察、粒度分析、薄片鉴定、测井资料和地震资料解释等为主要手段,研究渤海湾盆地东营凹陷北部陡坡带坨826块沙三上亚段砂砾岩沉积特征。结果表明,坨826块东部和西部沙三上亚段砂砾岩尽管与母岩距离相近,但受物源性质和搬运机制差异影响,其成分、结构和构造明显不同,其储集性能也具差异。东部砂砾岩以牵引流沉积为主,分选好,颗粒支撑,原始孔隙度较高;西部砂砾岩以重力流沉积为主,分选差,杂基支撑,原始孔隙度较低。研究区沙三上亚段砂砾岩为扇三角洲前缘亚相沉积,具有东(郑366次级古冲沟)、西(郑361—郑369次级古冲沟)2个物源通道,形成岩性和物性差异较大的扇三角洲前缘复合朵叶体,包括碎屑流沉积、水下辫状河道、分流间湾、河口坝及席状砂5个微相,其中水下辫状河道和席状砂较为发育,碎屑流沉积在研究区西部更为发育。由下至上,扇三角洲总体呈退积—进积沉积旋回。
Based on core observation,grain size analysis,thin section identification,well logging and seismic data interpretation and other methods,the sedimentary characteristics of E_(2)s_(3)^(1)(the glutenites in the upper section of the Sha 3 member of the Shahejie formation)were studied in Block Tuo 826 in the northern steep slope zone of the Dongying sag in the Bohai Bay basin.The results show that although both the glutenites from the eastern and the western E_(2)s_(3)^(1) are close to the parent rock,but their compositions,textures and structures are obviously different from each other due to different provenances and transport mechanisms,and as a result,their reservoir physical properties are different too.The eastern glutenite is dominated by tractive current deposits with good sorting and relatively high original porosity,and supported by grains,while the western glutenite is mainly composed of gravity flow deposits with poor sorting and relatively low original porosity,and supported by matrix.The E_(2)s_(3)^(1) glutenites deposited in fan delta fronts have two sediment transport pathways(one is the eastern Z366 secondary paleogulley and the other is the western Z361-Z364 secondary paleogulley),and composite lobes with larger differences in lithology and physical properties form,which include 5 microfacies,i.e.,debris flow deposit,underwater braided channel,interdistributary bay,mouth bar and sand sheet,among which the underwater braided channel and the sand sheet are developed,and the debris flow deposits are more developed in the western part of the study area.From bottom to top,the fan delta generally show a retrograding to prograding cycle.
作者
闵伟
MIN Wei(Petroleum Development Center,Shengli Oilfield Company,Sinopec,Dongying,Shandong 257000,China)
出处
《新疆石油地质》
CAS
CSCD
北大核心
2021年第4期428-436,共9页
Xinjiang Petroleum Geology
基金
国家自然科学基金(42072134)
山东省重大科技创新工程项目(2017CXGC1608)。
关键词
渤海湾盆地
济阳坳陷
东营凹陷
沙三段
砂砾岩
沉积特征
物源
扇三角洲
Baohai Bay basin
Jiyang depression
Dongying sag
Sha 3 member
glutenite
sedimentary characteristic
provenance
fan delta
