| Monitoring is an essential component of CO2 injection and storage projects in order to manage the injection process, identify leakage risks, provide early failure warnings, determine the movement of CO 2 plume and provide input into reservoir models. In-situ monitoring provides critical and direct data points that can be used to fulfill the above objectives. However, downhole sensors that can withstand the harsh conditions and run over decades of the project life cycle remain unavailable. A new idea of ceramic coaxial cable temperature, pressure and strain sensor has recently been put forward and the sensors are under development.;A high pressure high temperature (HPHT) testing system was developed in order to characterize the novel ceramic coaxial cable sensors under combined temperature, pressure and strain conditions with water, oil, brine, CO 2 and CO2/brine mixture. Tests were conducted on a semi-rigid coaxial cable temperature sensor under combined temperature and pressure conditions with water. Besides, a preliminary test was conducted on the ceramic coaxial cable pressure sensor model to help with the design of the sensor.;The semi-rigid coaxial cable temperature sensor showed an excellent ability of recording the actual temperature of hydraulic water with a constant resolution of +/-1 °C. The preliminary test on ceramic coaxial cable pressure sensor model decided stainless steel as the proper material for sensor jacket. |
