Reef Reservoir And Deposition Characteristics At Upper Member Of Yingshan Formation Of The Middle Ordovician In Xike-er Area Of Tarim Basin

Since Outcrop has the property of visibility, measurability, integrity, accuracy, testability and being researched by various scales and precision, the outcrop is the most ideal prototype of establishing diverse geological models. As the development of Sedimentary Geology theories and extension of Oil-Gas Exploration practice, it is increasingly important to return to the Outcrop and establish prototype of geological models that serving different research goals.The paper is guided by theories of Sedimentary, Carbonate Reservoir Sedimentary, Carbonate Reservoir Geology, Geochemistry and so on, and conducts systematic research towards Reservoir and Sedimentology problems at the Upper Member of Middle Ordovician outcrop reef and beach complex of Yingshan Formation located in Tarim Basin. The following results has been acquired:By conducting specific geological and geophysical investigation on Yingshan Formation reef and beach limestone outcrop in Xike-er areas, the paper illustrated the characteristic of landform of reef and beach in study area. The initial discovery of reef, which at Upper Member of Yingshan Formation beneath the stratigraphy of Yijianfang Formation or Dawangou Formation in Tarim basin, demonstrated the growth of reef at Upper Member of Yingshan Formation, this discovery of reef in Xeke-er area may extend the research goals of discovering reef beach body's reservoir into further strata in the Tarim basin.The paper continues to systematically illustrate the sedimentary characteristics of reef , including the reef beach body's growth, scale, shape, composition, reef-building organism, organism community, and Microfacies type and characteristics, and defines the type of Upper Member of Yingshan Formation reef in Xike-er area falls into the category of Calathium baffle reef , which the reefs and beach body is characterized by point reefs and beach body within the carbonate platform , thus a geological pattern of reef and beach complex body growth in this area is established. Geochemistry Analysis method was employed to restore the characteristic of ancient environment of reef-forming so that the reef-forming mechanism, mode and reef evolvement have been studied. The paper then, by analyzing diagenesis and pore evolution feature of organic reef limestone at Yingshan Formation in Xike-er area, clarified different Stage of diagenesis exerted correspondent effects on reef reservoir, among which, the effect of the atmosphere water karstification in paleo-epidiagenesis, burial dissolution , burial cavity filling and tectonism is the most significant.Metallogenic element, source, properties, pathway and space of the fluorite mineralization in Xike-er area have also been Investigated. The coupling relation between reef and fluorite mineralization, which shows the control of reef and Structural Hydrothermal activity over the distribution of fluorite mineralization, has been discussed.