Research on Diagenesis of Chang 8 Reservoir in Heshui Area of Ordos Basin

Diagenetic evolution law of oil and gas reservoir is one of the main research contents in oil and gas exploration.The study of reservoir diagenesis is aimed at those diagenesis cases which cause physical property changing,it discusses the evolution of reservoir pore to predict favorable hydrocarbon distribution.The thin section,cathodoluminescence and scanning electron microscopy are applied to analyze the petrological characteristics,authigenic minerals,pore development,diagenesis of Chang 8 reservoir sandstone in Heshui area of Ordos Basin.The result shows that the main authigenic minerals include kaolinite,chlorite,illite,calcite,quartz and feldspar.Diagenesis types mainly include compaction,cementation,metasomasis,dissolving,dissolution,etc.compaction and cementation damage the reservoir porasity,while dissolution and metasomasis improves porosity and permeability of reservoir.