Thermal conductivity of rocks under high pressure conditions

摘要

To exactly evaluate thermal conductivity of a rock specimen taken from a great depth, pressure effects have to be taken into consideration. We developed a new measurement system of thermal conductivity of rock specimens under high confining pressure and high pore-fluid pressure. This system consists of a commercial thermal conductivity meter, a high pressure vessel in which the rock specimen, sensors of thermal conductivity measurements were installed and two high resolution syringe pumps. One of the syringe pumps is for controlling confining pressure; and the other is for pore-fluid pressure. Both the pumps are able to monitor fluid flow rate and cumulative volume change of pore fluid in rock specimen assembly during testing. We examined the effects of high pressure on thermal conductivity in rock specimens of five terrestrial rock types. Thermal conductivity clearly increased with increasing effective pressure for both dry and wet (water saturated) samples.