Properties of Oil Shale In-situ Pyrolysis and Coupling Process of Underground Coal Gasification
|Keywords||oil shale and coal in-situ pyrolysis and gasification pore structure permeability coupling characteristics|
and coal resources associated in our country,the technology of in-situ mining oil shaleby underground co-gasification coal and oil shale was creatively put forward.Thistechnology can realize in-situ mining oil shale, improve heat-value and quality of gas.Based on the process characteristics of underground co-gasification of the oil shaleand coal,adopting microscopic experiments, the thermal properties of oil shale werestudied and analized systematically; Adopting model test and numerical simulation,the evolution law of temperature field of oil shale layer and coal layer, interactivefeatures and oil and gas and heat fluid solid coupling characteristics duringco-gasification were studied; Combining the results of experiment and model test, theunderground co-gasification technology of oil shale and coal was constructed.Theresults show that:(300~550℃）is the main phase in which most of organic matter wasreleased. pore volume and quailities increase fastly in400℃~600℃; oil shale andsemicoke have obvious fractal characteristic, oil shale and semicoke of600℃havethe lowest fractal dimensions.the permeability of oil shale increases first and thendecreases, corresponding temperature of peak is400℃, with increasing of porepressure, permeability decline; With the increasing of oil shale particle size, themaximum gas production declined, the temperature corresponding to the maximumgas production moved to the high temperature zone. whenφ(O2)is40-45%,temperature-rising rate is7℃/min、extend rate of gasification face is0.036m/h, theextend of temperature field is continuous and stable, the temperature change of oilshale and coal are synchronously. With the increase of temperature, the pressuregradient of coal and oil shale layer improve.