Boron-coated straw neutron detector for well-logging

Neutron detectors for well logging require stable operation in an extreme environment of high temperatures, (175C up to 260C), high mechanical vibration, and shock. Helium-3 tubes have been the preferred solution, as they satisfy these requirements to 175C, can be configured in small packages, are easy to fabricate, have low power requirements, and offer high detection efficiency. The supply of 3He gas has dwindled in recent years, however, and this medium can no longer support the demand in well- logging and other fields. Proportional Technologies Inc. (PTI) has developed boron-coated straw (BCS) detectors that have been shown to successfully replace 3He tubes in homeland security and neutron science applications. PTI has also developed a detector designed to withstand extreme temperatures. With recent developments PTI & apos;s straws are ultrasonically welded into all metal tubes and formed into corrugated structures that enhance the straw wall area by as much as two fold. The new construction is virtually impervious to temperature extremes. The basic Boron coated foil can be taken to 1000C and -200C repeatedly with no effect on the integrity of the coating nor foil structure. The corrugated structures lock together and substantially stabilize the straw walls against extreme vibration and shock. For this project, we propose a Fast Track development of a commercially attractive BCS-based neutron detector for well logging. The detector will share many of the attractions of 3He tubes, including compact size, high efficiency, low power consumption, and reliable operation in extreme environments. (of at least 250C). This will take the straw detector well beyond the temperature and robustness capabilities of 3He detectors and open new horizons in well logging. Commercial Applications and Other Benefits: Neutron detection is of substantial importance to US and world economy by aiding in discovery of new oil and gas fields. As newer oil field exploration is moving into depths where temperatures easily reach 250C, we expect the proposed straw neutron detector will provide a substantial increase in operational temperature and also to provide unexcelled reliability reducing the high cost of oil and gas exploration. As such, this development is very important to US economy moving forward.