Experimental Study On Thermal Evolution Of Hydrocarbon Generation Of The Coal In The Middle Coal Seam On Dalian River Group At Yilan No.3 Coal Mine

The coal in the middle coal seam on Dalian River Group at Yilan No.3 Coal Mine has the features that the coal is good,the coal seams are concentrated and thick.According to the theory of coalification,because the long flame coal has good gas condition,we select the coal in the middle coal seam on Dalian River Group at Yilan No.3 Coal Mine as the main research object.We did the gold tube thermal simulation experiment,then we obtained the characteristics of hydrocarbon and non hydrocarbon yield at different temperatures.The kinetic parameters of the product were obtained through the hydrocarbon kinetic calculation.I analysis the yield characteristics and guess the order of molecular cracking: C5,C4,C3,C2;I compare the activation energy distribution in order to predict the order of macromolecular reaction: first the macromolecular break up and appear C6-14,later appear C2-5,generate CH4 at last I analysis the apparent activation energy and find that in the low temperature stage CH4 comes from the analytical free gas and adsorbed gas,according to the yield characteristics of CO2,and it is inferred that the source of CH4 is the loss of methyl group in methoxy group.In intermediate stage considering the stage of pyrolysis products from other hydrocarbon CH4 sources the second pyrolysis by long-chain alkanes;at high temperature,CH4 is derived from toluene pyrolysis.I do the simulation of the coal seam burial history and evolution history of the coal in the middle coal seam on Dalian River Group at Yilan No.3 Coal Mine and I obtain that the vitrinite reflectance distribution of the coal seam is 0.53%-0.73%.The sample is humic coal and Kerogen is type ?,so that it generate lots of gas.I use the relationship between vitrinite reflectance and gas yield and the equal depth line of coal seam floor to get the original generated gas contour map.I collecte coal reservoir characteristics and geological structure background of the coal in the middle coal seam on Dalian River Group at Yilan No.3 Coal Mine.There is coal outcrope.The gas changed because of the development of normal faults in the mine field,hydrogeological conditions and mining influence.I analyze the present situation of gas distribution and find that the original generation of gas enriched and fugitived of different degree.