DEVELOPMENT OF A HIGH DATA RATE, FLUIDIC VORTEX THROTTLE, MUD PULSE TELEMETRY TRANSMITTER FOR MEASUREMENT WHILE DRILLING

THE OBJECTIVE OF THIS PROJECT IS TO PROVIDE THE OIL WELL LOGGING INDUSTRY WITH AN INEXPENSIVE, HIGH SPEED MUD-PULSE TELEMETRY SYSTEM. THE ABILITY TO GET REAL-TIME DATA FROM THE BOTTOM OF A BOREHOLE WHILE DRILLING EXPLORATORY, DIRECTIONAL, AND HORIZONTAL HOLES FOR OIL AND GEOTHERMAL WELLS AND CORING ALLOWS DRILLERS TO DRILL FASTER. ADDITIONALLY, THE ABILITY TO GET REAL-TIME DATA ALLOWS DRILLERS TO WORK MORE COST-EFFECTIVELY AND MORE SAFELY, BECAUSE THEY ARE ABLE TO REACT TO CHANGING DOWN-HOLE CONDITIONS FAST ENOUGH TO PREVENT BOTH BIT AND SENSOR DAMAGE, AS WELL AS BLOWOUTS. IN THIS WAY, EQUIPMENT CAN BE SAVED AND ENVIRONMENTAL DISASTERS AND THEIR ATTENDANT CLEANUP COSTS AVOIDED. CURRENTLY, MEASUREMENT-WHILE-DRILLING TELEMETRY IS LIMITED TO LESS THAN3 BITS PER SECOND (BPS); IT CAN TAKE AS LONG AS 5 SECONDS TOTRANSMIT JUST A SINGLE THREE-DIGIT NUMBER, A RATE MUCH TOO SLOW FOR CLOSED-LOOP CONTROL. FLUIDIC MUD-PULSE TELEMETRY HAS BEEN DEMONSTRATED AT OVER 30 BPS UNDER LABORATORY CONDITIONS, BUT NO ATTEMPT HAS BEEN MADE TO IMPLEMENT THE TECHNOLOGY. VORTEX CENTRIFUGAL-PRESSURE FORCES CAUSE THROTTLING OF THE DRILLING MUD THUS PRODUCING WATER-HAMMER PRESSURE PULSES THAT ARE PICKED UP AT THE WELLHEAD. BECAUSETHE THROTTLING OCCURS WITHOUT MOVING ANY MECHANICAL PARTS, RESPONSE IS VERY FAST. RECENT ADVANCES IN VORTEX THROTTLE TECHNOLOGY (INCLUDING ADVANCES IN STRATEGIC DEFENSE INITIATIVE TECHNOLOGY AND NUCLEAR FUEL REPROCESSING CONTROL)SUGGEST THAT IMPROVEMENTS BEYOND 30 BPS ARE POSSIBLE, AS ARECONFIGURATION IMPROVEMENTS THAT MAKE A SINGLE, MODULAR, MUD-PULSER VALVE IMPLEMENTATION PRACTICAL. IN PHASE I OF THE PROJECT, A HIGH PERFORMANCE FLUIDIC VORTEX MUD PULSER WITH A DATA RATE OF UP TO 50 BPS IS BEING DESIGNED. EMPHASIS IS PLACED ON A PRACTICAL, LOW COST DEVICE THAT CAN WITHSTAND DRILLING VIBRATIONS AND EROSION AND HAS REDUCED ACTUATION POWER REQUIREMENTS. IMPROVED METHODS OF ACTUATIONAND INTERFACING WITH SENSORS ARE BEING EXAMINED. IN PHASE II OF THE PROJECT, A PRACTICAL PROTOTYPE MUD PULSER CAPABLE OF OPERATING UNDER FULL FLOW OPERATING CONDITIONS IN A DRILLPIPE IS TO BE BUILT AND TESTED.