Abstract: A method of using a survey system comprising at least one sensor. The method comprises operating the survey system to provide information regarding the orientation of the sensor relative to the Earth at a first resolution level while the sensor is a first distance relative to the Earth's surface and operating the survey system to provide information regarding the orientation of the sensor relative to the Earth at a second resolution level while the sensor is a second distance relative to the Earth's surface. The second distance is larger than the first distance. The second resolution level is higher than the first resolution level.

Abstract: A method and apparatus are provided for determining an orientation of a drilling tool of a drilling system configured to drill a borehole into the Earth's surface. The method includes providing a survey system including at least one sensor within the drilling system. The sensor is configured to provide orientation information. The survey system is operable at a plurality of resolution levels. The method further includes operating the survey system at a first resolution level while the drilling tool is a first distance relative to the surface. The method further includes operating the survey system at a second resolution level while the drilling tool is a second distance relative to the surface. The second distance is larger than the first distance. The second resolution level is higher than the first resolution level.

Abstract: Wellbore survey methods and apparatus for wireline and measurement-while-drilling operations are disclosed which include a gyroscope, wherein the gyroscope has a spin axis, aligned with the instrument axis, and further having two sensitive axis orthogonally related to the spin axis and to each other. In addition, the wellbore survey apparatus contains a drive means, functionally connected with the gyroscope, to rotate the gyro about the instrument axis. The wellbore survey apparatus also contains a set of accelerometers, wherein the sensitive axis are aligned orthogonally to each other, and said drive means is functionally connected to the accelerometers to rotate the accelerometers about the instrument axis. Sensors determine the azimuthal direction of inclination of the wellbore at a first location therein and while traversing from said first location.

Abstract: Wellbore survey methods and apparatus for wireline and measurement-while-drilling operations are disclosed which include a gyroscope, wherein the gyroscope has a spin axis, aligned with the instrument axis, and further having two sensitive axis orthogonally related to the spin axis and to each other. In addition, the wellbore survey apparatus contains a drive means, functionally connected with the gyroscope, to rotate the gyro about the instrument axis. The wellbore survey apparatus also contains a set of accelerometers, wherein the sensitive axis are aligned orthogonally to each other, and said drive means is functionally connected to the accelerometers to rotate the accelerometers about the instrument axis. Sensors determine the azimuthal direction of inclination of the wellbore at a first location therein and while traversing from said first location.

Abstract: A wellbore survey method and apparatus which includes a gyroscope, wherein the gyroscope has a spin axis, aligned with the instrument axis, and further having two sensitive axis orthogonally related to the spin axis and to each other. In addition, the wellbore survey apparatus contains a drive means, functionally connected with the gyroscope, to rotate the gyro about the instrument axis. The wellbore survey apparatus also contains a set of accelerometers, wherein the sensitive axis are aligned orthogonally to each other, and said drive means is functionally connected to the accelerometers to rotate the accelerometers about the instrument axis. Sensors determine the azimuthal direction of inclination of the wellbore at a first location therein and while traversing from said first location. Attitude references of the wellbore with regard to said first location are determined while the tool is continuously traversing through the wellbore.

Abstract: A method for well borehole survey is set out. A sonde supports X and Y accelerometers and X and & sensors on a rate gyro having a Z axis aligned with the sonde. On a slickline, or within a drill string, the sonde is used to measure four variables, these being G.sub.x and G.sub.y, A.sub.x and A.sub.z. This enables well azimuth and inclination to determined. Measuring depth enables a survey to be made.

Abstract: A method for well borehole survey is set out. A sonde supports X and Y accelerometers and X and & sensors on a rate gyro having a Z axis aligned with the sonde. On a slickline, or within a drill string, the sonde is used to measure four variables, these being G.sub.x and G.sub.y, A.sub.x and A.sub.z. This enables well azimuth and inclination to determined. Measuring depth enables a survey to be made.