MOE Key Lab of Marin Reservoir Evolution and Hydrocarbon Accumulation Mechanism,ChinaUniversity of Geosciences(Beijing)MLR Key Lab of Shale Gas Resources Survey and Strategic Evaluation,China University of Geosciences (Beijing)

为了研究腐泥煤的孔隙结构特征,基于低温液氮吸附和压汞试验,应用孔隙分形理论探讨了腐泥煤的孔隙结构及分形特征。结果表明:腐泥煤具有3种不同的孔径分布,类型Ⅰ微孔和中孔含量较高,以4 nm孔隙最为发育;类型Ⅱ微孔和小孔较发育,峰值孔径为2、4、30 nm;类型Ⅲ孔隙整体发育较差;腐泥煤孔隙具有分形特征,由压汞试验数据得到的孔隙体积综合分形维数为3.17~3.90,由低温液氮试验数据得到的孔隙比表面积分形维数为2.59~2.93。孔隙体积综合分形维数与孔隙总体积呈正相关关系,随着综合分形维数的增大,微小孔比例上升,中孔和大孔比例减少;孔隙比表面积分形维数与孔隙度有微弱的正相关关系,与灰分呈负相关关系,变质作用对腐泥煤的孔隙结构起到了均一化的作用。

in order to study the pore structure features of sapropelit,based on the cryogenic nitrogen adsorption and mercury intrusion test,the pore fractal theory was applied to discuss the pore structure and fractal features of sapropelite. The results showed that sapropelite would havethreedifferent pore size distributions. Type I would have high contents of the micropore and mesopore and the 4 nm cracks were well developed.Type Ⅱ would have micropore and small pores well developed and the max pore diameter was 2,4 and 30 nn. Type would have the pores generally poor developed.Sapropelite pores would have fractal features,the datafrom the mercury intrusion test showed that the comprehensive factal dimension of the pore volume was 3.17~ 3.90,and the data from the cryogenic nitrogen test showed that the fractal dimension of the pore specific surface area was 2.59~2.93.The comprehensive fractal dimension of the pore volume and the general area of the pores would be in a positive related relationship. With the comprehensive fractal dimension increased ,the micropore content would be increased and the mesopore andmacropore contents would be decreased.The fractal dimension of the pore specfic surface area and the porosity would be in a weak posive eated relationship and would have a negative related relationship to the ash content.T'he metamorphism would have a homogenization role to thepore structure of sapropelite.

国家自然科学基金资助项目(41272176)；