The Study Of Sedimentary Microfacies On L Oil Layer In LaoJunmiao Oil Field

In this paper, Paleogene reservoir L is elected as the object of study, which located in Laojunmiao belt of Jiuxi basin, using advanced theories of sedimentology, petroleum geology and geophysics, based on outcrop, combining with drilling and logging data, researching the characteristics of Sand body distribution,sedimentary facies and sedimentary microfacies, the characyeristics of sedimentary evolution and depositional facies distribution characteristics of the plane of Paleogene reservoir L in laojunmiao belt of Jiuxi basin analysised systematically, discussing the reservior-forming factors of Laojunmiao Oilfield Paleogene L, clearing the main control factors of reservior, definited the reservior type and then making a detailed description to its characters, at the same time making a evaluation of favorable exploration target zones.On the basis of the formation divided and constrastion, using core and logging curves, laojunmiao paleogene oilfield can be divided into two big parts,the river depositional system and the delta depositional system, and further subdivided into three sub-facies are braided river, delta plain and the delta, in which L3 developed into braided river deposition, L2 mainly delta plain deposition, L1 the delta front deposition.By the clear sedimentary facies and sedimentary microfacies type, this paper discusses the space-time evolution and distribution characteristics of the sedimentary system, the characteristics of sedimentary facies plane and sand body distribution, sand bodies all distributes as a band speard from southeast to northwest. Rock types of Laojunmiao Oilfield Paleogene reservoir L are quartz sandstone and quality quartz feldspar lithic sandstone, cementing material is mainly clay cementation, with seldom calcareous cement. Cement types are mainly pore type, contact-pore type and contact type, debris particles arranged as mosaic-bracket-shaped, grains are contacted point-point, indicating the weak compaction and moderate cementation.In-depth analysis the reservior development theories of Laojunmiao oilfield Paleogene L reservior, the reservior types are mainly structural reservoir and lithology-structural composite reservoir, in which the structural reservoir developed by tectonism on the basis of depositional system is the main piont. The migration, accumulation and aggregation of oil and gas are mainly controled by factors of tectonic movement, fault and sedimentary facies, Laojunmiao Oilfield Paleogene reservoir L near the center of Jiuxi basin, river dam, delta plain distributary channel and delta front underwater distributary channel are the favorable reservoir facies. Combing with the sand body thickness of favorable micro-phase, oil-test, drill-test data, porosity, permeability, oil saturation and other indicators, analyzing each layer of the L reservior on the reservior properties of reservior sand body with clustering mothed. On that basis, predicts the favorable zone of each layer in Laojunmiao oilfield L reservior.