Study On Sedimentary Microfacies Of 1 St Member Of The Shahejie Formation Of Hean Area In Dongpu Depression

This paper according to reservoir beds of 1st member of the Shahejie formation (Es1)of Hean area in Dongpu Depression, Taking sediment logy,lithology,Logging study,sequence stratigraphy,structural geology,petroleum geology etc theories as guidance, and adopting sublayer comparison method of"cycle comparison, grading control", Are used to systematically research stratigraphic characteristics based on the study of geological background and divisions of sub stratums. The types of sedimentary microfiches are divided and on the basis of lithological characteristics, sedimentary structure characteristics and logging fancies. The paper predicts the character and trend of the distribution of sedimentary microfiches and sand body, and discusses the relationship between microfiches and reservoir, oil and gas distribution.There are three units relatively development of sand body of The 1st Member of Shahejie Formation in Hean-area, they are the 7#-9# of sandstone of Es1u and the 3#-4# and 1#-2# of two sandstone of Es1 d which, sand layer 4# marks nearly, reservoir most development, good connectivity, sand body gradually north, northeast thinning pointed out along the south west and west content source direction. Microfacies study of the results showed that the sedimentary environment is a period of main shallow lake-half a deep lake-delta front-former delta alternate sedimentary environment, which have been distinguished as follows subaqueous distributary river course,river-mouth bar, between tributary wan, front sheet sands, distal bar and other microfacies.The study based on the sedimentary fancies, combined with oil and gas distribution, analyzed that the most favorable reservoir fancies belt is the underwater distributary channel sandstone, followed by mouth bar sandstone. By the influence of river course, underwater distributary channel distributes alternating with interdistributary bay which forms the principal source-reservoir-seal assemblage mode. The underwater distributary channel sand bodies which should be the main destinations of exploration of this area in the near future is not merely good physical properly, it is also favourable places for hydrocarbon accumulation. Sand-body development and structural matching is the high-yield area in the study region, oil and gas accumulation in structural highs.