Suri Glam Ordovician Majiagou M51 _1-5 Sedimentary Diagenesis And Subsegment

The thesis is based on sedimentary petrology, reservoir geology and other researches, with the combination of macroscopy and microscopic view, observe the cores in the field and describe the microsection indoors, combine the drilling, well logging and production test datas, analysis by scanning electron microscope, cathodoluminescence, the conventional properties, mercury porosimetry analysis of test methods,make a careful study of sedimentary microfacies and diagenesis in M51-5submember of Sulige southern region, find out the characteristics of rock strata, the characteristics of karst landforms, sedimentary microfacies distribution law and the reservoir diagenesis types. On this basis, this paper sums up the influences that sedimentary microfacies, diagenesis and karst landforms have on the development of the reservoir.Through the analysis of the regional symbol correlation, lithology and electrical characteristics, completed the stratigraphic division and correlation of M51-5submember in the study area, reasonable and fine stratigraphic division has laid a good foundation for the study of sedimentary facies. through the observe of rock core and outcrop in the field, combine with microsection and logging data, measure the sedimentary facies and microfacies, determine the deposition phase-plane distribution of reservoir in the study area. The M51-4submember of the region of interest is the evaporated tidal flat facies of continental sea carbonate in Early Ordovician. Including three subfacies (supratidal zone, intertidal belt and sublittoral zone) and several microfacies. The west of Ma55sub-member is evaporative tidal flat facies and the east is restricted platform facies, between which is an arc transition zone. The most favorable sedimentary microfacies of Ma51-4is gypsum concretion dolostone on the supratidal zone, then followed by gypsiferous dolomite on the intertidal zone and dolomite of the middle tidal flat. The most advantageous facies belt of Ma55is dolomitic tidal flat in the west of the research area.On the basis of sedimentary facies, sedimentary microfacies, by a large number analysis for ordinary and casting sheet image, discuss the diagenesis and pore evolution. The dolomite reservoir of the study area has experienced many types of diagenesis, such as syngenesis dolomitization, the buildding-up and metasomasis of syngenesis gypse, neomorphism, hypergene karstification, burial dolomitization and dolomite cementation, burial dissolution, mineral packing action, dedolomitisation and dolomite cementation. Among them, dolomitization, supergene karstification and burial dissolution play a constructive diagenesis for reservoir porosity, the destructive diagenesis for reservoir porosity is dedolomitization, mineral packing action. Through the study of pore evolution, the gypsum dissolution pore mud-fine powder dolomite have the largest reservoir porosity and the best properties.Through the analysis of the influences that sedimentary microfacies, diagenesis and karst landforms on the development of the reservoir, prediction of distribution of the major reservoir of M51-5submember in the study area, this can provide a basis for the next exploration and development.