Study On The Reservoir Characteristics Of Carbonate Buried Hill In Guangrao Oilfield

Guangrao buried hill reservoir is extra-super heavy oil pool of carbonatite, which is the kind of fracture and limestone cave. In the earlier stage of development, the situation, water containing highly and breakthrough fast, has already appeared in the reservoir of Guangrao buried hill, which deeply affected the long-term efficient exploration of the reservoir, because of the irregular carbonatite storage space distribution and the cavern's multi-scale. Therefore, it provides reliable geological basis for the efficient exploration of the carbonate reservoir in the Guangrao buried hill by the research of fine characterization and description for the reservoir.This paper, which taking Guangrao buried hill as research object, analysis the developmental features of carbonate rock's reservoir pore space from the macro and micro, classifies the accumulating space of the studying region, analysis the controlling factors, on the base of multi-scale date including core, logging, well survey, earthquake, production performance and so on. The researchs find out the space distribution of the carbonate reservoir in Guangrao buried hill, recognize and predict the advantageous reservoir developing area on the basis of the geophysical materials, such as logging, earthquakes and so on, make the water-oil relations and the oil reservoir types clear, and explain controlling roles the reservoir plays for the oil distributions. After that, the main conclusion of this article is:The paper gets the distribution characters of the Guangrao buried hill layer from the type well, cut plane of framework to the all wells in the studying area, by the combined method of field geological mapping and sedimentary cycles-lithology combination. In the profile, the thickness of the layers in the Guangrao buried hill has changed a little. The stratigraphical dip angles are about 20 degrees, which performance as a gentle inclination to the north. In the plane, the exposure of the boundary stereotype in the outcrop has some rules. The type-boundary sections are essentially parallel, and the strike is NWW trend.The main storage space type of the carbonate reservoir of Guangrao buried hill is fracture and cavern related to fracture. Ordovician storage space types in the studying area mainly include structural fracture, corroded fracture, interparticle pore, brecciated cavern. The main storage spaces are formed by the sectonic process and the denudation. The reservoir they consisted of is fractural and vugular. And the favorable reservoir is Ordovician buried-hill crust of weathering. According to the explanation of well logging and earthquake, the advantageous reservoir of Guangrao buried hill distributes by the hill in the high part of structure in plain view, and usually does not connect with each other.Vertically, the advantageous reservoir of Guangrao buried hill develops by unconformity surface. As the increasing distance from the unconformity, pore-cavity-fracture distribution becomes bad, and petro physical property changes as the same way.