REMOTE LEAK SURVEY CAPABILITY FOR NATURAL GAS TRANSPORT STORAGE AND DISTRIBUTION SYSTEMS

IT IS IMPORTANT TO DETECT NATURAL GAS LEAKS FOR WORKER SAFETY REASONS AS WELL AS FOR ENVIRONMENTAL CONSIDERATIONS. THE ACCEPTED TECHNIQUES FOR DETECTING SUCH LEAKS ARE BASED ON SLOW AIR SNIFFING SYSTEMS THAT DETECT THE MAJOR CONSTITUENT OF NATURAL GAS (METHANE) THROUGH CHEMICAL MEANS. ALTHOUGH AIR SNIFFING TECHNIQUES ARE SENSITIVE, THEY ARE SLOW AND MUST BE EMPLOYED IN THE IMMEDIATE VICINITY OF THE SUSPECTED LEAK. REMOTE OPTICAL DETECTION OF METHANE HAS BEEN DEMONSTRATED, BUT SYSTEMS BASED ON THIS TECHNIQUE HAVE BEEN TOO COMPLICATED FOR FIELD USE. A SENSOR APPROACH HAS BEEN DEVELOPED THAT USES A SEMICONDUCTOR DIODE LASER SOURCE. CALCULATIONS SHOW THAT THE PERFORMANCE OF SUCH A SYSTEM WILL EQUAL OR EXCEED THAT OF THE COMMERCIAL SNIFFER DEVICES. BECAUSE IT USES A DIODE LASER, THIS DEVICE CAN ALSO BE INTEGRATED INTO A SMALL, BATTERY-OPERATED PACKAGE FOR HANDHELD OPERATION. IN PHASE I, A LABORATORY VERSION OF THE DEVICE WILL BE CONSTRUCTED, AND ITS SIGNAL-TO-NOISE RATIO WILL BE MEASURED. THIS INFORMATION IS BEING COMPARED WITH EXPECTATIONS FROM CALCULATIONS AND USED TO PREDICT THE PERFORMANCE OF AN OPTIMIZED PROTOTYPE DESIGN WHICH WOULD BE CONSTRUCTED AND TESTED IN PHASE II.