Research On Favorable Area P Rediction Of The Yan 8 And Yan 9 Reservoirs In Wangyao Area Of Ansai Oilfield

The major reservoir Chang 611-2 of Wangyao area in Ansai oilfield has developed for nearly 30 years,now the main layer is in the later period of development and into high water cut stage,In order to dig a new reserves and realize the steady rise in crude oil output,a research on Yanan group is needed.Guided by the sequence stratigraphy,sedimentary petrology,logging geology and other related disciplines theory and research method,combining with the logging,core sample,well test as well as production test data,this paper makes researches of the Yan 8 and Yan 9 reservers of Wangyao area on stratigraphic classification and correlation,sedimentary facies analysis,reservoir characteristics,logging interpretation,oil and gas enrichment regularity and so on.This paper analysis suggests that Yan 8 and Yan 9 belongs to delta front depositional system,which can be divided into underwater distributary channel and underwater interdistributary bay microfacies.The underwater distributary channel sand is frame sand.The distribution of sand bodies are controlled by sedimentary facies.Yan 8 and Yan 9 reservoirs are mainly coarse-medium and medium-fine grained clastic arkose and arkose,and the sorting characteristic is good.The reservoirs mainly develop intergranular pore and feldspar dissolved pore.The porosity of Yan 8 reservoir is mainly distributed between 8%? 22%,average porosity is 15.1%;The permeability of Yan 8 is mainly distributed between 0.05?98 mD,average permeability is 6.8 mD.The porosity of Yan 9 reservoir is mainly distributed between 9%?23%,average porosity is 16.3%;The permeability of Yan 9 is mainly distributed between 0.3?135 mD,average permeability is 9.8 mDThe reservoirs belongs to low porosity and low permeability reservoir.Based on the lithology,physical property and the sedimentary microfacies,Yan 8 and Yan 9 reservoirs are divided into three classes,and the ? reservoir is the most.Through the study of "four properties",a set of suitable for the reservoir parameter interpretation model of researching area has been established,the oil-water identification chart was plotted.Combining the sedimentary microfacies,sand body distribution,structural characteristics and reservoir evaluation factors,this paper analysises the oil enrichment distribution of this area,optimizes 28 favorable exploration areas,which include 3 type I,6 type ?,19 type ?,and provide geological basis for further exploration and development.