| Abstract |
As awareness of climate change is increasing with each passing day, many countries have taken pledges to reduce and control the emission of CO2 in the atmosphere. In that respect, non-conventional energy sources will play a huge role in achieving such a goal. Moreover, it is reported by different researchers that renewable energy will contribute more than conventional sources in the future. Therefore, geothermal energy will be vital as it is the only source of non-conventional energy that remains operational 98% of the time and is independent of weather conditions. Hence, to increase the geothermal source's maximum efficiency, maximum heat must be collected at the wellhead. To attain this target, the high thermal conductivity cement should be deployed at the bottom of the well to facilitate the maximum transfer of heat energy from the formation to the working fluid. While at the upper section of the well, cement with lower thermal conductivity should be used in order to avoid the dissipation of the collected heat energy to the surrounding formation. Therefore, this paper shows the long-term experimental result of the thermal conductivity of Class H, C, and G that have been cured in wet and dry conditions for a time period of more than 450 days. It was observed that as the mechanical properties of cement depend upon curing time in the same manner in the initial days of curing, the thermal conductivity of the cement fluctuates and becomes relatively constant after certain curing days. Moreover, the thermal conductivity of the samples cured in dry conditions always had a lower value than those cured in wet conditions. The purpose of choosing neat cement for this study was to give a basic understanding of the respective cement behavior and what to expect when some additives are added to them. |