Sedimentary Facies Of Chang2 Of Yanchang Formation In The Jiyuan Area On Ordos Basin

The Jiyuan area of Ordos basin, which possesses abundant resources but lower exploration degree, has bright prospect in oil and gas exploration.By collecting data about outcrop, core, and many other elementary geological data ,at the same time using sedimentary analyses and geological analyses, in the thesis ,sequence division were applied, type of sedimentary facies were identified, the extension of sand bodies, distributing of sedimentary facies and physical property of reservoir were studied .Sedimentary facies of the chang2 oil-bearing beds of Yangchang Formation in Jiyuan is realized by the research above. Finally the favorable area were found out.Based on the primary marks of contrast in region , stratum of the Chang2 oil-bearing beds of Yangchang Formation in Jiyuan area are divided into Chang23,Chang22,Chang21from lower to upper. Five connecting-well section are built which to contrast the stratum.The study showed ,delta sedimentary facies is main sedimentary facies of the Chang2 oil-bearing beds in Jiyuan area and the deltaic plain distributery channel sand body is good reserveoir. The sand bodies distributed from northeast to southwest dominated by sedimentary facies.Reservoir properties and distribution are mainly controlled by sedimentary facies. Because of simple configuration, gentle structure, the effect of the tectonic movement is relatively limited. The result indicates the characteristics of the Reservoir petrology are lower mineral maturity and high structure maturity. The physical property represent that Chang 2 is middle pore and low permeability or low pore and low permeabilityThe soure rock and the distribution of the centre of oil generation well relate with the distribution of deep lake in research area. The favorable source-reservlir-caprock group can be formed for the frequency of lacustrine treansgression and regression . The favorable area can be found out in Chang2 oil-bearing beds of Yanchang Formation by the analysis of sedimentary facies , the distributing of sand body, the character of structure and the property of reserveoir ,etc.