Ordos Basin Tabamiao Area Of ​​upper Paleozoic Reservoir Sedimentology,

Based on lots of achievements of predecessors, directed by reservoir sedimentology, high-resolution sequence stratigraphy and petroleum geology, taking full advantage of loggin, core and thin section data from different wells, this paper has taken detailed study on the Upper Paleozoic strata in Tabamiao area. The research focus on the types and distribution of sedimentary facies and microfacies, characteristics of high-resolution sequence stritigraphy and sequence-lithofacies palaeogeography development, diagenesis types and their order, pore kinds and features, reservoir properties and their distribution. Finally, the favourable areas have been predicted.The sedimentary system groupe of Taiyuan Formation and Lower Shihezi Formation of Upper Carboniferous in the research area, which include lacustrine delta sedimentary system, transition delta sedimentary system and beach-barrier sedimentary system, can be divided into continental sedimentary system groupe, marine sedimentary system groupe and transition sedimentary system groupe. Lacustrine delta sedimentary system can be furtherly divided into braided river delta and meandering river delta. Transition delta sedimentary system is mainly river-dominated delta. Beach-barrier sedimentary system consists of tidal flat and barrier sandbar sedimentation.Under the guidance of high-resolution sequence stritigraphy, the paper has taken a detailed study of the characters of different grades base level changes, and also a correlation of high-resolution sequence, then established the high-resolution sequence framework. At last, we have described lithofacies-paleogeography map of different period selecting the half cycle of base level elevating of middle-term base level cycle as the mapping unit, and have detailedly discussed the sandbody distribution during the lithofacies-paleogeography evalution prosess. The paper has come to the conclusion that the sedimentation system allocation, sandbody distribution characteristics and the river channel distribution and its transfer all have close affinity with base level changes.According to plenty of thin section and other analysis data, sandstone types, pore types and their features of the study area have been discussed. The diagenesis is the dominant factor which controls the reservoir properties. Destructive diagenesis types mainly include compaction, pressure solution and cementation. Constructive...