Research On Favorable Area Prediction Of Chang 7 Reservoir Construction In Jingan Area

Chang7 reservoir in Jingan area has the characteristics of low porosity,low permeability and low saturation.It belongs to typical low permeability and extra-low permeability reservoirs and mainly develops lithologic reservoirs.By synthesizing all kinds of data,Snch as well logging data,core analysis data,oil test data and so on,the sedimentary microfacies and their petrophysical facies in the reservoir,petrology,porosity and pore structure characteristics,physical characteristics and reservoir control factors of Chang 7 reservoir are studied.Combined with the fine logging interpretation technique of geological condition constraint,the reservoir oil-water layer and the hydrocarbon source rocks identification is carried out,and the prediction of favorable area in the study area is finally completed.The understandings are listed as follows.1.The provenance came from the north to east direction,and the Chang7 period was the development stage of the lake basin in the Ordos basin.The Jingan area was generally in the delta front sedimentary Snbfacies environment of Zhijing river delta system,and the sedimentary microfacies were divided into Snbaqueous distributary channels.There are three types of river faces: underwater distributary channel,flanks and interdistributary bay.2.The clastic components of Chang 7 reservoir in Jingan area are similar,mainly composed of feldspar sandstone and lithic feldspar,the interstitial matters of which are different,the pore is mainly intergranular,the pore throat is good performance,the reservoir physical property is slightly poor.The diagenesis is mainly in the middle diagenetic stage A,and the local area can reach the middle diagenesis stage B.3.The reservoir types are mainly lithologic reservoirs,which are controlled by sources of oil and gas,migration channels,migration dynamics,sedimentary factors,hydrocarbon source rocks and reservoirs edc.Chang 7 reservoirs are accumulated in the sources,and the generated hydrocarbons are transported into the reservoir with high permeability,and the closer the source rocks are,the more oil and gas accumulation is.4.Combined with the characteristics of sedimentary facies distribution,distribution characteristics of hydrocarbon source rock,sand body distribution,test data and the reservoir characteristics and accumulation knowledge,the favorable areas is forecasted in the Jingan Area and two favorable target areas of class I,one favorable target area of class II and two favorable target areas of class III of Chang 7 reservoir formation are selected.