A Study On Micro-structure And Infiltrating Mechanism Of Chang 6 Reservoir Of Xing 13 Well Area In Zhidan Ilfield

This paper recording material,Survey materials and Actual examination materials,in situ large amount of well layer rocky resolution and accumulation micro phase analysis basis,because lack match with real productive practice,this research makes a quantitative annlysis on the pore structure/diagenesis by many experiments,such as thin sections,scanning electric microscope?SEM?,regular high pressure mercury penetration,rate-controlled mercury penetration and other methods.Main achievments are summarized as follows:Chang6 reservoir of Triassic Yanchang Formation in Zhidan Oilfield is belonging to the shallow lake delta-front sediment subfacies,and reservior sedmimentary types are mainly distributary channel microfacies,estuarine dam,far sand dam and distributary interbay,sand is more developed but the plane distribution is different.On average,the porosity is 10.77%and the permeability is 0.94×10^-3?m²,which is a typical low/ultra-low permeability lithologic reservoir.Chang6 reservoir are mainly arkose,poor psephicity,angular,medium degree of separation,the content of debris is 6.9%,low content of interstitial materialis 11.7%,cementation method is given priority to with pore-membrance type cementation,node-line contact is given priority to,high clay mineral content,especially in the development of chlorite,that is illite and kaolimite,overall maturity chang6 reservoir structure is not high,destructive diagenesis is strong,and poor overall property;The pore types of Chang6 reservoir in the research district mainly intergranular pore,throat types are mainly flake-bending sheet.Main pore combination types of pores,solution pores,intergranular pore,solution pores.Overall,the pore growth is poorer,throats were bent and complex,and its types was various,such as point and flake throat,tube bundle throats appeared alternately;Commonly found in the second type?II?,the third type?III?capillary pressure curve,high displacement pressure,low efficiency of mercury withdrawal,maximum into mercury saturation is low;The study area has a poor reservoir property,microscopic,complicated pore structure and high filler content of factors lead to complex oil-water two phase flow characteristics,high bound water saturation,two phase seepage axea small,two phase flow interference isstrong,overall lower reservoir movable fluid saturation;Reservoir property in the research area in the mutual influence of sedimentation,diagenesis.Based on the parameters of reservoir physical property,micro pore structure and infiltrating mechanism,drawing up the standard of reservoir classification and evaluation,classifying the formation in to five classes,?,?,?and?,?,?,?are evaluatedas best.