Sedimentary Micro Faces And Sand Connectivity Of Chang 2₂² Formation Of Triassic In Feng 18 Well Area In Ordos Basin

Feng-18 wells in Ordos basin, areas as 9.2km2, locats in Xiaojianzi Xiang in Dingbian county of Shaanxi province, belonging to Jihuang 32 block. The basic geological research has seriously lagged behind the development of reservoir.. This paper makes full use of 73 well logging, production dynamic data and the adjacent area’s drilling data, focusing on the analysis of the sedimentary micro faces and the connectivity of the sand bodies on the basis of small layer division and correlation.⑴By the sign layer, uniform thickness in principle, this paper selected F18-31 well as a standard well, within the cycle of comparison, conducting thin layer division and contrast. This paper divided the Chang-2₂² reservoir into three sand bodies as 2₂²-1, 2₂²-2, 2₂²-3 in the Feng-18-wells within innovation. The 2₂²-2 sand bodies is the main one. In the plane of the study area, the thickness of each sand body group showed the characteristics of thick middle and thin edge. The thickness of the 2₂²-1 sand body group is 4.3 to 9.9m. The thickness of the 2₂²-2 sand body group is 18.31 to 20.4m. The thickness of the long 2₂²-3 sand body group is 21 to 26.5m.⑵Using the logging data, combined with sedimentary background and the micro faces of delta plain sedimentary and braided fluvial sedimentary, this paper recognizes the Chang 2₂² sand group developed micro faces as central bar, channel filling, river stranded and flood plain. Among them, the Chang-2₂²2 sand body formation does not develop flood plain..⑶ By using static data combined with the dynamic ones, this paper studies the connectivity of sand bodies, and points out that the connectivity of sand bodies is determined by the degree of development of the diara, the consistency of micro faces and the thickness of the sand bodies.（1）The development of the diara in Chang 2₂²-1 is low, which leads to the poor connectivity of the sand bodies. The development in Chang 2₂²-2 is higher, which leads to the better connectivity of the sand bodies.（2）The connected sand bodies with the same sedimentary micro faces, the water injection effect fast, and the sand bodies’ connectivity is good. These with different sedimentary micro faces, the water injection takes long time and barely effects, and the sand bodies’ connectivity is poor.（3） The thickness of each single sand body is larger than 3.6m, that is beneficial to the sand body connectivity between wells.