Sequence Control Of Coal Measures Gas Reservoirs Characteristics In Yushe-Wuxiang Block

In order to study the sequence control regularity of coal reservoir,shale reservoir and tight sandstone reservoir in coal measures.Based on the basic geological data such as drilling cores and logging curves and related experimental data in Yushe-Wuxiang block,the integrated use of sedimentology,sequence stratigraphy,organic petrology,mineralogy,oil and natural gas geology,coal geology,rock physics theory,the basic geological disciplines such as by field investigation,indoor test,theoretical research,pay attention to the application of general research scheme,comprehensive analysis and research area of key strata,upper palaeozoic test results,the analysis of samples in combination with regional sedimentary tectonic evolution history and burial characteristics,analysis of various lithology combination rules combined with sedimentary sequence,in-depth study of coal gas reservoir physical characteristics,The control of sequence on reservoir property is discussed.The results show that there are 2 kinds of sedimentary facies,3 kinds of sedimentary subfacies and 4 kinds of sedimentary microfacies in taiyuan formation,and 1 kind of sedimentary facies,1 kind of sedimentary subfacies and 3 kinds of sedimentary microfacies in shanxi formation.The taiyuan formation and shanxi formation can be divided into five tertiary sequences,namely SQ1?K₁ sandstone-K₂ limestone?,SQ2?K₂ limestone-K₄ limestone?,SQ3?K₄ limestone-8 coal?,SQ4?8 coal-K₇sandstone?,and SQ5?K₇ sandstone-K₈ sandstone?.Sequence corresponding to different sedimentary environment is put in bigger difference,frequent transgressive and regressive alteration in the nature of the sedimentary water body,the difference of supply conditions,combined with the source makes the coal reservoir physical property presents obvious stratabound sex,from sequence SQ1 to sequence SQ5 and TOC mud shale reservoir type,air content,index and average pore diameter presents a trend of increase with the decrease of the first,specific surface area,entrance,porosity and BET than area and total pore volume were presented a trend of decrease the first increases,and present a trend of increase with the decrease of the first,organic matter maturity decreases.The specific surface area,total pore volume,adsorption capacity and gas content of coal reservoir show a trend of first decrease and then increase,while the average pore diameter shows a trend of first increase and then decrease.The TOC,clay mineral content,BET specific surface area and BJH pore volume,gas content and methane concentration of sandstone reservoirs increased with the increase of burial depth,while the quartz content and average pore diameter decreased with the increase of burial depth.