A DOWNHOLE QUANDRANT-BY-QUADRANT FLOW TOOL FOR GEOTHERMAL APPLICATIONS AT UP TO 350 DEGREES C.

AN 82 MM DIAMETER DOWNHOLE GEOTHERMAL QUADRANT-BY-QUADRANT FLOW TOOL (QFT) IS UNDER DEVELOPMENT IN WHICH ANY AND ALL OF THE FOLLOWING FOUR ULTRASONIC MODES MAY BE SELECTED: TRANSMISSION, REFLECTION, TAG CORRELATION, AND NOISE. THE REASON FOR EMPLOYING ULTRASONICS IS TO OBTAIN THE REQUIRED PERFORMANCE WHILE AVOIDING THE LIMITS ON OTHER SENSORS CAUSED BY THEIR USE OF MOVING PARTS, FLOW-RESTRICTIVE ORIFICES, OR SENSITIVE SURFACES WHOSE HEAT TRANSFER PROPERTIES ARE LIKELY TO DEGRADE QUICKLY IN THE HOSTILE HIGH-TEMPERATURE (250 TO 350 DEGREES CENTIGRADE) DOWNHOLE ENVIRONMENT. A SPECIAL ADVANTAGE OF ULTRASONICS IS ITS ABILITY TO MEASURE ANNULAR FLOW QUADRANT-BY-QUADRANT. SUCH PROFILE DATA COULD CONTRIBUTE UNIQUELY TOWARD UNDERSTANDING THE ORIENTATION OF DOWNHOLE FISSURES. THE REASON FOR INVESTIGATING AS MANY AS FOUR MODES IN PHASE I IS THAT EACH IS SUITED FOR ONLY PART OF THE FLOW RANGE OR FLOW CONDITIONS. FROM AMONG SEVERAL PIEZOELECTRIC TRANSDUCERS WHOSE CRITICAL TEMPERATURE IS 400 DEGREES CENTIGRADE OR HIGHER, ONE MUST BE SELECTED THAT IS MOST EASILY ADAPTED TO CONFIGURATIONS REQUIRED BY THE FOUR MODES. IDEALLY, SEVERAL MODES WOULD SHARE PAIRS OF TRANSDUCERS. TESTS OF THE NONELECTRONIC PORTION OF THE FLOW TOOL WILL BE CONDUCTED TO 350 DEGREES CENTIGRADE. AT ROOM TEMPERATURE, ANNULAR FLOW SYSTEM TESTS WILL BE CONDUCTED QUADRANT-BY-QUADRANT FROM 0.05 TO 5 FT/S, A 100:1 RANGE, IN A 6 IN. PIPE. A COMMERCIALLY AVAILABLE ELECTRONIC INSTRUMENT ALREADY OPERATES IN MULTIPLE MODES, BUT IT NEEDS TO BE REPACKAGED IN PHASE II TO MEET THE THERMAL, CHEMICAL, PRESSURE, MONOCONDUCTOR, SMALL DIAMETER AND OTHER DOWNHOLE REQUIREMENTS. THE ADAPTABILITY OF THE GEOTHERMAL TOOL TO OIL AND GAS DOWNHOLE EXPLORATION AND LOGGING, DIAGNOSTIC LEAK DETECTION AND SENSING OF FISSURE ORIENTATIONMEANS THAT, IF THE QFT IS SUCCESSFUL IN PHASE I, PRIVATE FUNDING IS LIKELY TO BE FORTHCOMING FROM INDUSTRY.