The Study Of Sedimentary System Of Upper Paleozoic In East Ordos Basin

Ordos basin is one of the most potential gas reservoir region in China. Aiming at the low degree opinion about the gas reservoirs of the east of the upper Paleozoic in Ordos basin, integrating geology and the observation and description of outcrop and drilling core, through the analysis of single factor with synthesize factor drawing the sedimentary facies and its space distribution of the east of the upper Paleozoic in Ordos basin in order to renew its sedimentary evolution history and distribution.It shows the main control factor of forming and distribution character of gas reservoir in this region., and offering important basic data or theory to forecast the most prospective sandstone bodies and farther gas exploration and exploitation in Ordos basin.Firstly, on the basis of stratigraphic classification and comparison study, the strata from Benxi formation to later Shiqianfeng formation was divided into twoâ… order sequences(super-term stratigraphic base level circle) and eightâ…¡order sequences(middle-term stratigraphic base level circle), and 22â…¢order sequences(middle-term stratigraphic base level circle), middle cycles could been divided into many short cycles.Through the observation and description of a large of drilling cores in macroscopic and microcosmic aspect, facies marks summarized, And through the analyses the main vertical section to distinguish 3 sedimentary system types of the Upper Paleozoic,8 sedimentary system(facies),22 subfacies and some microfacies, and discussed detailly the characteristic of all kinds of facies, subfacies and microfacies and spatiotemporal distribution of them.Ordos basin is a cralon basin, The extent of oil and gas accumulation is controlled by sedimentary facies. So it is important to study the distribution mode of the sand body Therefore, based on the achieves of some geologies, concluding that the provenances in Ordos basin. It cloud know the sedimentary facies and the distribution mode of sand body.Finally the article analyzes the enrichment regularity of gas pools and forecast the promising sandstone reservoir and prospect play.By the above research, the main innovations in the thesis are as follows:1. According to the exploration practice for many years of the Ordos basin, analyzing the main controlling factors of forming gas reservoirs combining the well data of Yanchang field.2. Established the sequence stratigraphic framework of the strata from Benxi formation to later Shiqianfeng formation. And the author try to discuss the relationship between the sequence stratigraphy and gas accumulation.3. With the studying of valid hydrocarbon source rock evaluation, oil and gas migration, accumulation, and preservation, the paper puts forward the exploitation prospect plays.