The Reservoir Geological Characteristic Of Yan10₁Reservior In Yuan47Region

As one primary oil-bearing series of Ordos Basin, exploration and exploitation of Yan10reservoir of Yanchang formation in Jiyuan area have an important place in the reserves and oil productions of Changqing Oilfield in the past few years.However, short of recognition of Yan101stratum’s serious heterogeneity and low estimation of geological reserves in early days affect the progress of exploration and exploitation of this area thoroughly. This paper gives the details of stratigraphic division and sedimentary characteristic of the Yan10reservoir in Wangpanshan area on combination of sedimentology and geophysics by a comprehensive study using core analysis data, logging data, well logging date and laboratory analysis data. By using reservoir geology theory and complementary research methods as the guide, it takes a systematic and thorough study into the area characteristics of reservoir rocks, diagenesis. characteristics of properties, pore structure characteristics and the characteristics of the heterogeneity and the main control factors of Yan1O1reservoir in this area can be classified and evaluated from the geological point,then The reservoir volume can be calculated and evaluated by the above research.Research shows:the Yan10reservoir of this area was subdivided into Yan101and Yan1O2and the bedthickness of this region is steady,moreover, Yan101is the principal producing formation.This area develops braid river and the main sand body microfacies is river and heart beach; The main kind of reservoir sandstone is chondro-mesograin arkose quartzite,kaolinite and kiesel,at the same time,hydrous mica stands most part of interstitial material; Reservoir property which belongs to mesporosity and low-permeability is bad; Solution pores-intergranular pore is the main types of pore and eservior space is small pore and thin throat; The Yan101reservoir of this area have existed serious intraformational、 interlamination and plane anisotropy. The main governing factors of reservoir characteristic in this area are sedimentation and diagenesis.The conclusion of storability recalculation this time shows that changes of oil-bearing area and effective thickness are the main governing factors of geological reserves,meanwhile, changes of porosity affects less than the above two facors.