Study On Reservoir Characteristics In Xin Anbian Oilfield

Xin’an Bian area has good prospects for exploration and development. Thus the reservoir evaluation research of the southwest edge area of Yan-Chang is significant to the improvement of the development effect of the block and acceleration of the area production.Based on the relevant documents and data of core and well logging,aiming at Xin’an Bian area,this paper studies on the formation characteristics of sedimentary, petrology, pore structure, physical properties and heterogeneity in order to obtain comprehensive and systematic knowledge of sedimentary and reservoir characteristics of the study formation.Under the restriction of K4, K2mark layer which develops well in target area,this paper gives a detailed stratigraphic division and correlation of Xin’an Bian area based on the principle of sedimentary cycle correlation,also establishs stratigraphic correlation profiles. Hu District7, Hu Yan District9, Hu Yan10area divided into four small layers:Yan91, Yan92, Yan1011, Yan1012. Xin’an Bian area is divided into six small layers:Yan9, Chang10i, Chang102, Chang103, Yan1011, Yan1012. According to the characteristics of petrology,structure and paleontology,this paper studies on the sedimentary fades and sedimentary system of Xin’an Bian area.The results show that:Yan9deposition facies is meandering river delta, subfacies is delta plains; Yan10and Chang10deposition facies is deposition rivers, subfacies is braided river. Based on the petro-logical characteristics, characteristics of pore formation, physical characteristics, reservoir heterogeneity characteristics and sensitivity characteristics of the study area, the reservoir characteristics are studied, research shows:Yan’an formation reservoir is a conventional low permeability sandstone reservoir, YanChang formation reservoir is middle porous and low permeable reservoir, and it has the characteristics of strong heterogeneity. The classification and evaluation of reservoir discoveries that Ⅰ, Ⅱ class reservoir distribution area is small and has good physical properties, they often developed in the underwater distributary channel and mouth bar area and that the III class reservoir has poor reservoir physical property, displayed throughout the whole study area outside the Ⅰ, Ⅱ class, mainly developed in interdistributary bay. The reservoir physical property is controlled by sedimentation and diagenesis, physical properties of the overall development is not good. Through the study of sedimentary phases and the reservoir characteristics, the geological basis for the exploration and development of the next step is provided.