Toshinobu Itoh
Makoto Miyairi
Japan Petroleum Exploration Co. Ltd.
Kiyoshi Kimura
Teikoku Oil Co. Ltd.
ABSTRACT
High temperature well logging tools for Geothermal well have been developed by the co-operation with the Japanese petroleum and Electrical Companies-under the sponsorship of Japanese government. The tools that were developed on this project are as follows:
· Multi-spacing Electrical - SP Log
· Micro-spherical - Caliper Log
· P-S Acoustic - Caliper Log
(Including of Micro-seismograph Log)
· Optical Borehole TV
· Production Logging Tools
(Temperature, Pressure, Continuous Flowmeter and Borehole Sampler) The environmental conditions of these tools are: temperature as high as 275°C and pressure as high as 500 kg/cm2. After the high temperature test of these tools, these tools were field tested during 1978 and 1979 at the bore-hole conditions of Depth: 1200m, BHT: 202deg C, BHP: 150kg/cm2. All the tools,
except the optical borehole TV, were successfully operated during long period tests.
According to the field test, the optical borehole TV, which consists of a camera tube, could be used only 4 hours at the borehole temperature of 150 deg C, and a high temperature TV, which consists of a semiconductor image sensor, is now under the development. The final temperature target of this TV camera is 4 hours at borehole temperatures as high as 250°C.