Study On The Development Of Micro Pores And Gas Storage In High Mature Shale In Northern Jiangxi

In order to study high mature shale characteristics of micro pore and its effect on storage performance in the northern Jiangxi,the paper used methods of mercury,low temperature nitrogen adsorption,studied the pore structure,pore size distribution,specific surface area;And used NMR?nuclear magnetic resonance?for porosity and permeability,used scanning electron microscopy to observe the pore morphology,type;Othermore,combined with ArcGIS technology for analysis of pore number,porosity.Then according to the data from the experiment,studied high mature shale pore development factors in Northern Jiangxi.Finally,discussed the control factors of high mature shale adsorption capacity and gas storage performance.Through the above research,some conclusions are obtained:?1?High mature shale pore structure diversity,contains slit shaped,irregular open hole and ink bottle hole,the ink bottle hole count a lot.The aperture is mainly distributed in micropores,holes?3⁶0nm?,the average pore size is slightly larger.The pore type is mainly brittle mineral dissolution pores,intergranular pores,and a lot of organic matter pore are observed.And a little small specific surface area?0.217 ¹6.4283m²/g,mean 7.1734m²/g?,high porosity?0.4%¹8.4%,mean 4.14%?,a little low permeability(0.0025⁰.0163*10^-3um²,mean 0.00985*10^-3um²).Characterization of pore based on ArcGIS show pore types of morphological diversity,pore size as follows: brittle mineral is greater than clay mineral hole and organic matter pore,organic matter pore is the least.?2?The content and type of clay minerals have effect on high mature shale pore development,clay minerals content has positive correlation with the pore volume,and negative correlation with average pore size and porosity,but brittle mineral to the contrary.The organic carbon content is positively correlated with pore volume and porosity.The type of kerogen from sapropel type to mixed type,specific surface area,total pore volume becomes larger.The maturity of organic matter on the effect of pore development is,from low mature stage to mature stage,pore volume,porosity decreases with the increase of maturity,high mature and over mature stage,pore volume and porosity increase with increasing maturity,while the specific surface area decrease with maturity increase as a whole.Mainly due to the low mature stage,the pore volume decreases with maturity,with the decrease of pore size,part of keyhole evolution for micropores,then specific surface area will temporarily increase,high mature stage,pore volume increase,pore size becomes larger,and the large aperture contribute little to specific surface area,which leads to the decrease of specific surface area.?3?High,over mature shale sample in Northern Jiangxi adsorption ability is strong.But its organic matter maturity and shale gas adsorption capacity show a certain degree of negative correlation,the main reason is the high,over mature stage,shale specific surface area decrease leads adsorption capacity fades,The organic carbon content,specific surface area,pore volume are positively correlated with the maximum gas adsorption.Different types of organic matter has different adsorption capacity,sapropel type is less than mixed type and humic type.There was a negative correlation between the porosity and the maximum adsorption,and the porosity directly control the amount of shale gas.It shows that high,over mature shale gas is most in free state,relatively small exists in adsorbed state.