Patent ID: 6216533
Filing Date: 2001-04-17
Classification: E21B

Abstract:
A downhole drilling parameter sensor device for use with drilling operations of a borehole used in oil and gas exploration, the sensor device comprising:a plurality of independent load cells orthogonally positioned within a drill collar wall of a drill string, where said drill collar has an inside diameter and an outside diameter, with said load cells comprising:a first Wheatstone bridge comprising four strain gauges orthogonally positioned within a ring configuration within said load cell; anda second Wheatstone bridge comprising a set of four strain gauges orthogonally positioned within a ring configuration within said load cell;a plurality of temperature sensors positioned within said drill collar wall and arrayed to measure temperatures at locations comprising said drill collar's outside diameter, said drill collar's inside diameter, and said load cells;a triaxial vibration sensor positioned within said drill string proximate to said load cells;a magnetometer array positioned within said drill string in physical association with said triaxial vibration sensor;a first pressure transducer positioned within said drill string in fluid communication with an annular volume surrounding said drill string within said borehole; anda second pressure transducer positioned within said drill string in fluid communication with an internal bore of said drill string;wherein said plurality of independent load cells provide for redundant measurements of weight-on-bit, torque-on-bit, and bending-on-bit forces parameters, said plurality of temperature sensors provide for measurements of temperature gradients across the load cells so as to correct said load cell measurements for any temperature dependent errors, said triaxial vibration sensor and said magnetometer array provide for measurements of drill string motion to provide for finding and tracking drill string rotational orientation within the borehole, and said pressure transducers provide for measurement of pressure variations so as to correct said load cell measurements for any pressure dependent errors.