In this paper,the reservoir microstructures of mudstone and sandstone from Qilian Mountain permafrost were tested by electron microscopy.Under the microscope,the mudstone is composed of tiny and uniform flaky polygonal blocks,so that the hydrate immerses in the mudstone.The sandstone has dispersed pores inside,thus the hydrate exists in the sandstone by pore-type filling.The thermal conductivity and thermal diffusivity of reservoirs bearing methane hydrate were measured by transient plane heat source method.At the temperature range of about-9.41 to 9.41 ℃,the thermal conductivities of the dried mudstone and the mudstone bearing methane hydrate are 0.577-0.853 W· m-1· K-1 and 0.704-1.050 W· m-1· K-1,respectively.At the temperature range of about-8.11 to 9.28 ℃,the dried sandstone and the sandstone bearing methane hydrate have thermal conductivity of 0.828-1.271 W·m-1·K-1 and 3.850-4.555 W·m-1·K-1,respectively.At the temperature range of about-9.41 to 9.41 ℃,the thermal diffusivities of the dried mudstone,the mudstone bearing methane hydrate,the dried sandstone,and the sandstone bearing methane hydrate are 0.712-0.894mm2·s-1,0.792-1.006 mm2· s-1,1.198-1.674 mm2 · s-1,and 1.403-1.769 mm2 · s-1,respectively.The data show that it is a good means to explore the existence of hydrate by measuring the thermal conductivity of intervals bearing gas hydrate.%采用扫描电镜测试了祁连山冻土区天然气水合物储层泥岩和砂岩微观结构.在显微镜下观察到,泥岩由微小均匀的片状多边形块体构成,这种微观结构使得泥岩中水合物以浸染状赋存;而砂岩内部存在分散状孔隙,砂岩中水合物为孔隙赋存.采用瞬变平面热源法测试了含甲烷水合物储层岩石的导热系数和热扩散率.在温度为-9.41～9.41℃时,干泥岩导热系数为0.577 ～0.853 W·m-1.K-1,含甲烷水合物储层泥岩导热系数为0.704～1.050W·m-1·K-1.在温度为-8.11 ～9.28℃时,干砂岩导热系数为0.828 ～1.271 W.m-1.K-1,含甲烷水合物储层砂岩导热系数为3.850～4.555W·m-1·K-1.在温度为-9.41 ～9.41℃时,干泥岩热扩散率为0.712 ～0.894 mm2·s-1,含甲烷水合物储层泥岩热扩散率为0.792 ～ 1.006mm2·s-1,干砂岩热扩散率为1.198 ～1.674 mm2·s-1,含甲烷水合物储层砂岩热扩散率为1.403～1.769 mm2·s-1.测试数据表明,对于孔隙型水合物,测定导热系数是一种较好的辨识水合物存在的辅助手段.
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