Highly porous basalt-fiber-based heat insulation for steam-heated oil wells in the Far North

Аннотация

An experimental and theoretical justification of the efficiency of a highly porous basalt-fiber-based heat insulation capable of providing geophysical equilibrium conditions for the existence of permafrost during the operation of steam-heated oil wells in the Far North is given. A mathematical model of heat transfer in highly porous fibrous materials is proposed to describe the steady-state mode of the process, with consideration given to Stefan–Boltzmann radiation into the pores of the highly porous material, thickness of the heat insulation layer, and temperature of the hot wall. The temperature dependence of the thermal conductivity of a highly porous heat-insulating material is obtained. It is shown that the thermal conductivity of a basaltbased fibrous heat-insulating material decreases by two orders of magnitude as its temperature rises to 930°C. The analysis performed provided new information of the parameters of the pore space of fibrous material in the processes of conductive heat transfer. The proposed solution makes it possible to calculate the thickness of a heat-insulating layer and concurrently optimize the porosity of the material. The results provide a basis for selecting suitable technological solutions.