Quality Evaluation On Low Permeability Reservoirs Of Beach-bar Sandy Body In Es₄^s Member,Binnan Oilfield,435 Area

Bohai gulf basin is China's important oil and gas basin,basin contains enormous amount of oil and gas resources.Along with the further exploration and development,the importance of low permeability reservoirhas become the main objects of oilfield exploration in recent years.Lijin sub-sag,northwest of the beach bar facies thin interbed is a kind of important low permeability reservoir,causing wide attention and considerable reserves of oil and gas have been discovered during previous exploration.Evaluation and development of this kind of reservoir effectively and increase the value of the low permeability reservoirs are important issues which are urgently in need of solution.The study take an example of 435 to analyze the work area,rock of this paper is to analyze the sedimentary background,the period of low permeability reservoir geological factors,optimization parameters for evaluation of low permeability reservoir comprehensive evaluation,the clear high quality reservoir distribution characteristics.Make full use of core,thin section observation,physical property analysis,logging,oil exploration and seismic data,and with the mature development of adjacent blocks known as the instruction,based on the research of sedimentary microfacies,reservoir diagenetic facies,reservoir characteristics research,and comprehensive evaluation on the low permeability reservoir classification,reveal the characteristics of high quality reservoirs and distribution range.1.The analysis of sedimentary faciesThe study on the basis of core observation,logging data analysis combined with thin section identification and adjacent regions for reference of existing research results in 25 Wells is carried out to identify the five types of sedimentary microfacies,revealing sedimentary microfacies plane and profile evolution.Overall,dam body,and beach ridge microfacies is parallel to the coast in a zonal distribution,thickness of sand body,is the main facies belt,the advantages of more development in group 1 and group 2.2.The diagenetic facies analysisBased on core observation,thin material,analyze different diagenetic facies types and compare lithofacies developmental differences in different sedimentary microfacies.Analysis shows that strong corrosion and weak cementation in the dam body and the beach ridge is favorable diagenetic facies,and crush real strong function,calcium cementation diagenesis phase are unfavorable diagenetic facies.3.The comprehensive evaluation on the reservoir characteristics and reservoir435 area in the section is a kind of low permeability reservoirs with the combintion of various types of reservoir space for the overall,and based on the analysis of reservoir characteristics,reservoir pore structure can be divided into three categories,including ? class,characterized by fine throat groove.Select six parameters controlling the reservoir quality of objective layer,including sedimentary microfacies,diagenetic facies,the types of pore structure,porosity,permeability,sand body thickness,and calculate the comprehensive reservoir quality index.Interms of the index,four types of reservoirs are divided,and? and ? reservoirs are the main targets of the development of exploration,? class high quality reservoirs are characterized by the biggest sand body thickness and strong dissolution of the dam body deposition,? class quality for reservoir sand body thickness is larger,the secondary dissolution and weak cementation formed under the action of beach ridge deposits.According to the characters of high quality reservoir development,the study points out that the high quality reservoir development area.