石油与天然气地质2025，Vol.46Issue(5)：1504-1521,18.DOI:10.11743/ogg20250508
深水重力流沉积类型及含油性对比
Types of deep-water gravity-flow deposits and comparison of their oil-bearing properties:A case study of the 7th-9th oil groups in the Triassic Yanchang Formation,Fuxian area,Ordos Basin
摘要
Abstract
In the Fuxian area of the Ordos Basin,the 7th-9th oil groups in the Triassic Yanchang Formation(also referred to as the Chang 7-9 oil groups)hold great petroleum resource potential.Previous studies mostly hold that sandstones in these oil groups are dominated by deltaic deposits.Although gravity-flow deposits have been discovered in the Chang 7 oil group in recent years,some issues remain unclear,including their existence and distribution range across the Chang 7-9 oil groups.Using core observations,grain size analysis,and thin section observations,we identify the primary types of gravity-flow deposits and their distributions,together with the comparison of reservoir characteristics and oil-bearing properties within.The results indicate that gravity-flow deposits are widely distributed across the Chang 7-9 oil groups in the Fuxian area,including sandy debris-flow deposits,turbidite-flow deposits,and slide-slump deposits.The sandy debris-flow deposits,among others,feature great thicknesses and massive beddings,with rip-up clasts visible.Their grain-size cumulative probability curves exhibit three primary patterns:a coarse-skewed single-segment pattern,a short-tailed two-segment pattern,and a two-segment pattern with high suspended component content.In contrast,the turbidite-flow deposits are thin,with incomplete Bouma sequences observable in cores.Their grain-size cumulative probability curves primarily show a fine-skewed single-segment pattern.In contrast,the slide-slump deposits are characterized by wrinkling deformation,convolute beddings,and stepped faults.The comparison reveals that the sandy debris-flow deposits are generally superior to the turbidite-flow deposits,exhibiting high reservoir quality,favorable oil-bearing properties,and high daily oil production from well tests.Among the widespread gravity-flow deposits in the Chang 7-9 oil groups in the Fuxian area,the sandy debris-flow deposits show the most extensive distribution,as well as the most favorable reservoir physical properties and oil-bearing properties.Therefore,they should be prioritized as significant targets for future exploration and development of tight oil in the Fuxian area.关键词
含油性/砂质碎屑流沉积/浊流沉积/滑动-滑塌沉积/重力流沉积/富县地区/鄂尔多斯盆地Key words
oil-bearing property/sandy debris-flow deposits/turbidite-flow deposits/slide-slump deposits/gravity-flow deposits/Fuxian area/Ordos Basin分类
能源科技引用本文复制引用
王琳茜,赵靖舟,高振东,魏繁荣,周世琪,孟选刚,闫新智,徐宁..深水重力流沉积类型及含油性对比[J].石油与天然气地质,2025,46(5):1504-1521,18.基金项目
国家科技重大专项(2016ZX05050). （2016ZX05050）
