A HIGH PERFORMANCE WELLBORE LOGGING TOOL USING FIBER OPTIC GYRO TECHNOLOGY

CURRENT STATE-OF-THE-ART WELLBORE LOGGING SYSTEMS HAVE BEEN APPLIED EFFECTIVELY TO MEASURE SHALLOW VERTICAL WELLS. THESE SYSTEMS HOWEVER BECOME ERROR PRONE WHEN THE WELLBORE INCLINATION APPROACHES THE EARTH'S ROTATION AXIS OR APPROACHES AN ORTHOGONAL DIRECTION TO EARTH'S GRAVITY. ADDITIONALLY, WHEN THESE SYSTEMS ARE REQUIRED TO OPERATE AT TEMPERATURES GREATER THAN 100 DEGREES CENTIGRADE, THEY MUST BE FITTED WITH A RECHARGEABLE COOLING SYSTEM WHICH IMPEDES THE MEASUREMENT PROCESS AND LIMITS DOWN HOLE MEASUREMENT TIME. ALL OF THESE PROBLEMS ARE ATTRIBUTABLE TO THE MEASUREMENT ABILITY AND LIMITED OPERATIONAL TEMPERATURE RANGE OF THE LOGGING INSTRUMENT'S SPINNING WHEEL GYROS. THIS PROJECT INVOLVES AN INNOVATIVE APPROACH TO A WELLBORE LOGGING INSTRUMENT WHICH ELIMATES THE PROBLEMS ASSOCIATED WITH THE CONVENTIONAL LOGGERS. THIS APPROACH INVOLVES THE USE OF LOW COST, SOLID STATE FIBER OPTIC STRAPDOWN GYROS IN A 3-AXIS MEASUREMENT CONFIGURATION ENABLING LOGGING OPERATIONS TO 25,000 FEET OR MORE, OPERATIONAL TEMPERATURE RANGE TO 200 DEGREES CENTIGRADES WITH INDEFINITE OPERATION TIMES, ACCURATE MEASUREMENTS INDEPENDENT OF WELLBORE ORIENTATION, AND ELIMINATION OF ALL ACTIVE DOWN HOLE GYRO ELECTRONICS. PHASE I WILL CONDUCT A DESIGN ANALYSIS OF THE PROPOSED FIBER OPTIC GYRO CONCEPT, DEVELOP A SINGLE AXIS DEMONSTRATION MODEL, AND CONDUCT LABORATORY ENVIRONMENTAL TESTING TO VERIFY HIGH PERFORMANCE MEASUREMENT CAPABILITY AT TEMPERATURES UP TO 200 DEGREES CENTIGRADE. IN PHASE II A WELLBORE LOGGING TOOL WILL BE DEVELOPED INCORPORATING THE PROPOSED FIBER GYROS, AND IT WILL BE FIELD TESTED.