论文详情
综合利用三维地震、钻测井及岩心资料,在塔河地区三叠系上油组中识别出了大型下切谷沉积体系。结果表明，该下切谷体系对下伏地层侵蚀作用强,相干体切片可见明显的下切河道特征,地震剖面上呈强振幅“V”形或“U”型反射,下切谷内部具短轴状强振幅反射特征,自然电位与自然伽马测井曲线均呈高幅箱形或钟形,岩性以灰色粗砂岩、中细砂岩为主,垂向上多套砂体叠置。同时,下切谷体系朝着东部、西南部和南部3个主要方向发育,且各部位下切谷宽度、深度、宽深比、弯曲度等特征各不相同,这与局部的地形地貌条件密切相关。该区下切谷的形成及演化受构造活动、沉积物供给和湖平面变化等因素控制。下切谷内充填的砂体及其末端发育的低位三角洲形成了良好储层,可作为该区岩性圈闭勘探的优选目标。
Comprehensive utilization of 3D seismic,well log and cores data,large scale incised valley depositional systems were identified in the upper oil-member of Triassic,Tahe area.The results suggest that the underlying strata are greatly eroded by these incised valley systems,with obvious incised channels on the seismic coherence slices.There are high amplitude reflections (HAR),in the shape of V and U,on seismic profiles.Besides,the deposits are composed of gray coarse sandstone and middle-fine sandstone,in which multi-sandstones superimposed in the vertical direction,and it is characterized of short-axial HAR.Spontaneous Potential (SP) and Gamma Ray (GR) logs display block or bell-shape curves with high-amplitude.Meanwhile,the incised valley systems mainly develop eastward,southwestward and southward,with different characteristics of width,depth,W/D and sinuosity,which is closely related to the local geomorphology conditions.The development of incised valleys in study area is dominated by the tectonic activities,sediment supply and lake level variation.The incised valley deposits and the lowstand delta that develop in the terminal end of incised valley could form good reservoirs,being favorable exploration targets for the lithological traps.
国家重点基础研究发展计划(973计划)项目(2009CB219407)、国家科技重大专项(2016ZX05026)和国家自然科学基金项目(41372115,91528303)联合资助。