Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool including the performance characteristics of a drill motor. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool including the performance characteristics of a drill motor. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

Abstract: An integrated, single collar measurement while-while-drilling tool is presented that comprises formation sensors, directional sensors, pressure sensors, a mud pulse telemetry device, and a turbine-generator power device configured in a single collar housing that is no longer than a standard drill collar. No electrical connections are made across drill collar tool joints. The tool provides high reliability and ease of transportation.

Abstract: A downhole tool for use in a wellbore, comprises a tubular member, such as a drill collar housing, in a drill string. The tubular member has at least one cavity formed on an external surface. At least one housing is adapted to be insertable and extractable in the cavity without further tool disassembly. The housing has at least one electrical device such as a battery stack disposed within. In another aspect, sensors are disposed in the housing for measuring downhole parameters of interest including, but not limited to, annulus pressure and annulus temperature. A method of replacing an electrical device in a downhole tool, comprises removing a first housing containing the electrical device from a cavity on an external surface of the downhole tool, and installing a second housing containing a second electrical device in the cavity without disassembling the tool further.

Abstract: A downhole tool for use in a wellbore, comprises a tubular member, such as a drill collar housing, in a drill string. The tubular member has at least one cavity formed on an external surface. At least one housing is adapted to be insertable and extractable in the cavity without further tool disassembly. The housing has at least one electrical device such as a battery stack disposed within. In another aspect, sensors are disposed in the housing for measuring downhole parameters of interest including, but not limited to, annulus pressure and annulus temperature. A method of replacing an electrical device in a downhole tool, comprises removing a first housing containing the electrical device from a cavity on an external surface of the downhole tool, and installing a second housing containing a second electrical device in the cavity without disassembling the tool further.

Abstract: An integrated, single collar measurement while-while-drilling tool is presented that comprises formation sensors, directional sensors, pressure sensors, a mud pulse telemetry device, and a turbine-generator power device configured in a single collar housing that is no longer than a standard drill collar. No electrical connections are made across drill collar tool joints. The tool provides high reliability and ease of transportation.

Abstract: A load cell for sensing weight and torque on a drill bit during a drilling operation includes a cylindrical load cell made from a material with minimum residual stress. A plurality of strain gages are arranged symmetrically on each load cell and electrically coupled to form two Wheatstone bridges. The load cells are mounted 180 degrees apart in radial pockets drilled in a drill collar wall. A half Wheatstone bridge from one load cell is electrically coupled with a half Wheatstone bridge from the other load cell to form a Wheatstone bridge for measuring WOB and a similar coupling is made to form another Wheatstone bridge for measuring TOB. In another embodiment, additional strain gages in another Wheatstone bridge measure differential pressure. The output of the pressure and weight bridges are electrically combined to provide a weight signal unaffected by differential pressure fluctuations.

Abstract: An apparatus and method for measuring differential pressure of mud internal a drill string and mud in a borehole annulus is disclosed.

Abstract: In the representative embodiments of the present invention described herein, new and improved methods and apparatus are disclosed for measuring various forces acting on an intermediate body between the lower end of a drill string and the earth-boring apparatus coupled thereto whereby the magnitudes and angular directions of bending moments and side forces acting on the earth-boring apparatus can be readily determined so that predictions can be made of the future course of excavation of the apparatus.