Sequence Stratigraphy Research And The Prediction Of The Petroleum Geological Conditions Of Later Carboniferous～Permian In Yingen-Ejinaqi And Its Surrounding Areas, Inner Mongolia

The Carboniferous-Permian in Yingen-Ejinaqi and it's surrounding area, Inner Mongolia, with greate thickness and vast dark mudstones, show a fine petroleum geological condition. But no systematic petroleum geological studies have ever been conducted because of the formidable geological and natural conditions. This paper, for the first time, based on the petroleum geological survey conducted by the greate geological survey of China Geological Survey Bureau, carry out outcrop sequence stratigraphic and sedimentary facies research on the Carboniferous-Permian, as means of biostratigraphy, sequence stratigraphy, sedimentary and petroleum geology, and analyze its sedimentary paleogeography, and predict the favorable hydrocarbon plays. This thesis draws primary conclusion and new fruit as follows:1,Based on the former study and the geological investigation in recent years for 25 measured sections and 35 observed sections, this paper correlates redefinites and the rock-stratigraphy units and its boundary of Carboniferous～Permian with a method of biostratigraphy and lithostratigraphy; and for the first time, strikes up the straum sequence of Carboniferous～Permian(exclude lower Carboniferous) in study area, which emphasis in Dongdewusu section(lower member of Amushan Formation),Wulanaobao section(Amusan Formation),Maihanhada section(Shuangbaotang Formation and Jinta Formation),East Yagan section(the bottom of Haersuhai Formation) and Chaheilingashun section(Haersuhai Formation).2,This paper firstly conducts the outcrop sequence stratigraphic research for the Carboniferous-Permian in study area, and divides 4 second-order sequences and 16 third-order sequences, it summarizes the characteristics of sequences,systerm tracts and parasequences, and discusses the formation and evolution mechanism of the parasequence, and divides the parasequences here into there kinds:coarsening-upward parasequence,fining-upward parasequence and interbeds of clastic rocks and carbonate rocks parasequence.3,This thesis, emphasizes on the comprehensive study of facies marks, such as lithology, sedimentary structure, paleotology, vertical sequence and geochemistry, and combined with the research of facies spatial arrangement, carries out detail analyse on sedimentary facies and lithofacies palaeogeography, and consider that the Carboniferous-Permian is mainly forms in the context of neritic shelf, and the depositional systems should be divided into fan-delta depositional system,braided river delta depositional system,open coastal depositional system,restricted coastaal depositional system,neritic depositional system,carbonate platform depositional system and bathyal epositional system, and 19 sedimentary facies in detail; and it also analyzes the characteristics of sedimentary paleography of Later Carboniferous-Permian in study area, in the framework of third-order sequence.4,The thesis analyzes the characteristics of source rocks,resivior and seal rocks, and predict the favourable stratum and area for their development; analyzes the features of the source-reservoir-cap assemblage, and classifies it into there kinds:"self-sourcing and self-reservoir",""lower-sourcing and upper reservoir" type and "upper-sourcing and lower-reservoir" type; it also predict the favourable area for petroleum exploration, points out that the Juyanhai depression and Wutaohai depression are the favourable blocks for hydrocarbon generation, and the transition zones between Luyuan uplift and its adjacent depression and the southern part of Teluoxitan are the favourable area for petroleum exploration of Carboniferous-Permian in study area.