The Research Of Sedimentary Facies About Chang 6 Oil Formation In Hujianshan-jiyuan Area

As the second largest continental facies sedimentary basin in China, the Ordos Basin covers 250,000 square kilometers and possesses abundant oil and gas resources with a bright prospect for the exploitation and development of oil and gas. It has been one of the important tactical areas for future exploitation and development of oil and gas in China.Hujianshan-jiyuan is the important generative area of oil in the Ordos basin. As primary oil beds in west area, the effective exploitation and reasonal development of chang 6 oil beds are significant for the development of Changqing Oilfield. To further study the rules of the hydrocarbon accumulation and distribution, exploration direction in the area, it is necessary to study sedimentary system, palaeogeographic reconstruction, rule of sedimentary facies and sand bed, the source of sediment in the chang 6 oil beds of Hujianshan-jiyuan area in a detailed way.On the basis of the theories of continental facies sedimentary petrography, petroleum geology, sequence stratigraphy, petroleum geochemistry and geology investigations in the field and research indoors, combined with the dates of geological background, lithological association, sedimentary structure, geochemistry, chemical analysis of reservoir organic compound, the thesis studies the distribution rules of stratum and sandstone, the development rules of sedimentary subfacies, reservoir characteristics, sedimentary sources ,the rules of accumulation and distribution of oil in chang 6 oil beds of Hujianshan-jiyuan area. The following results are obtained in the thesis:The chang 6 stratum is divided into 7 sub-stratums:6₁¹, 6₁², 6₁³, 6₂¹, 6₂², 6₃¹ and 6₃². The thesis sets the boundaries of each stratum and describes lithological characteristics of the sub-stratums, which enables the classification of the sub-stratums in the studied area more reasonable and in a more detailed way.With identification of detrital composition and heavy mineral, the conduct of geochemistry REE analytic procedure, combined with traditional geology ways, the thesis aims at judging the various direction of provenance in the studied area in a comprehensive way. The result that north Yin shan ancient land and northwest alashan ancient land are the main sediment source of several deltas.By the sedimentary and sequence stratigraphy means, and so on the sedimentary system and petroleum geology are studied.With the research of sedimentary facies, the characteristic of sand was studied. Then the rule of oil and accumulation, The advantage areas of exploration future were proposed.