| Abstract |
Century Drilling and Energy Services has developed a Pressure, Temperature, Spinner (PTS) instrument with significant improvements. The PTS instrument is designed to continuously measure and record downhole temperatures, pressures and flows in geothermal wells. The PTS instrument is capable of operating at 315oC and up to 200 bar pressure. Interchangeable impellers allow the impeller best suited to the flow conditions in the well to be used. The PTS instrument operates on mono conductor cable in eline mode (surface readout) and on slickline in downhole memory mode. The external diameter of the instrument is 45mm (1 æî) which enables logging in slimline investigation wells. A robust strain gauge pressure sensor, and resistance thermometer produce accurate pressure and temperature data. The modular design of the instrument allows an impeller section to be connected to the instrument to provide spinner measurements. Four spinner channels are transmitted to the surface giving increased reliability and confidence in the data. When operating on mono conductor cable the data is transmitted from the downhole microprocessor to the surface. Pressure, temperature and spinner data is displayed in real time giving a picture of the well during the logging operation. In downhole memory mode the logged data including downhole temperature, pressure, impeller speed, internal temperature and time is stored in the memory for up to 24 hours logging. Depth, line speed, line weight, wellhead pressure and time is stored in the surface unit. The memory module can be operated in wells where the temperatures exceed 315oC. This option is cost effective and suitable for operators where real time data is not required. |