Leaders:  B. Roth
Team:  K. Bremer
Year:  2011

Aim of the subproject T5 (pressure sensor) is the development of a pressure sensor which can operate under harsh geothermal environment in the downhole. Different sensor technologies for pressure measurement are examined for their applicability within a drilling system. For this purpose feasible solutions for the intended measurement range and the whole measurement chain are considered. The whole sensor system is simulated and characterized.

Within this project different pressure measurement methods (piezoelectric, piezoresistiv, optical and so on) were compared to one another. By evaluating the comparison results, it becomes obvious that the intensity modulation by means of stress-induced birefringence is the most suitable optical pressure monitoring method for the deep geothermal drilling. The sensor prototype based on the stressed induced birefringence was developed within the project. High-temperature optical elements: LEDs and photodiodes, based on the Silicon Carbide (SiC) were chosen for the pressure sensor.

Funding and Partners