Research On Sedimentary Facies And Reservoir Characteristics Of Upper Ordovician Complexed Reef-beach In 82 Well Area Of The Tazhong First Break In Slope

Under the guidance of the theories of advanced carbonate deposition,palaeontology,reservoir and petroleum geology, and associated with the relevant domestic and external latest progress, the traditional field and interior measures were adopted , which adjoined with advanced test research techniques, to study the complexed reef-beach sedimentary microfacies' styles and characteristics systematically in Tazhong 82 well field and reservoir classification evaluation were appraised and law of development lateral and long direction were discussed. And the geological models of the high-quality reservoir were established and the distributions of high-quality reservoir strata were forecasted and ultimately the favorable gathering area for exploration was delineated.Aimed at the features that the development of strata mainly controlled by paleogeography,complexed reef-beach grew upward and sea level relative variable, on the basis of comprehensive analysis lithology and borehole logging features, and applied the theories of stratigraphy principles and methods, Lianglitage Formation were divided into 5 lithology sections, and classified into 12 sublayers from bottom to top. and recognized 12 microfacies within 4 facies such as platform margin reef (bioherm),grainstone beach,platform margin lime-mud mound and interbank sea.Combined with analysis of reservoir diagenesis and main controlled factors, the reservoir developed patterns were established and the cognition were gained that the development of upper Ordovician reef-beach reservoir were controlled by the reef's geography , reef facies combination and nonage atmosphere fresh water dissolution, that is to say that the distribution of reservoir and oil pool fitting the reef's geography, which will bring significantly meaningful in the exploration and exploitation on the carbonate platform margin.Research on the reservoir developed features and changing regularity laterally, the reservoir's regularities of distribution, and established the geological patterns of the reservoir, synthetically evaluated and predicted high quality reservoir distribution and favorable exploring goals. It has significant meaning to the next step exploration in this region.