Wellbore inertial directional surveying system
Abstract
A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single offshore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on an electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block about the gimbal axis. Angular rates of the sensor block about axes which are perpendicular to te gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as themore »
- Inventors:
- Issue Date:
- OSTI Identifier:
- 5629994
- Application Number:
- ON: DE83018102
- Assignee:
- SNL; ERA-08-053436; EDB-83-174440
- DOE Contract Number:
- AC04-76DP00789
- Resource Type:
- Patent
- Resource Relation:
- Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 02 PETROLEUM; 03 NATURAL GAS; 47 OTHER INSTRUMENTATION; DIRECTIONAL DRILLING; MEASURING INSTRUMENTS; NATURAL GAS WELLS; WELL LOGGING; OIL WELLS; WELL LOGGING EQUIPMENT; DESIGN; ALGORITHMS; BOREHOLES; COMPUTERS; ERRORS; GYROSCOPES; ORIENTATION; WELL DRILLING; WELL SPACING; CAVITIES; DRILLING; EQUIPMENT; MATHEMATICAL LOGIC; WELLS; 020300* - Petroleum- Drilling & Production; 030300 - Natural Gas- Drilling, Production, & Processing; 440400 - Well Logging Instrumentation
Citation Formats
Andreas, R D, Heck, G M, Kohler, S M, and Watts, A C. Wellbore inertial directional surveying system. United States: N. p., 1982.
Web.
Andreas, R D, Heck, G M, Kohler, S M, & Watts, A C. Wellbore inertial directional surveying system. United States.
Andreas, R D, Heck, G M, Kohler, S M, and Watts, A C. Wed .
"Wellbore inertial directional surveying system". United States.
@article{osti_5629994,
title = {Wellbore inertial directional surveying system},
author = {Andreas, R D and Heck, G M and Kohler, S M and Watts, A C},
abstractNote = {A wellbore inertial directional surveying system for providing a complete directional survey of an oil or gas well borehole to determine the displacement in all three directions of the borehole path relative to the well head at the surface. The information generated by the present invention is especially useful when numerous wells are drilled to different geographical targets from a single offshore platform. Accurate knowledge of the path of the borehole allows proper well spacing and provides assurance that target formations are reached. The tool is lowered down into a borehole on an electrical cable. A computer positioned on the surface communicates with the tool via the cable. The tool contains a sensor block which is supported on a single gimbal, the rotation axis of which is aligned with the cylinder axis of the tool and, correspondingly, the borehole. The gyroscope measurement of the sensor block rotation is used in a null-seeking servo loop which essentially prevents rotation of the sensor block about the gimbal axis. Angular rates of the sensor block about axes which are perpendicular to te gimbal axis are measured by gyroscopes in a manner similar to a strapped-down arrangement. Three accelerometers provide acceleration information as the tool is lowered within the borehole. The uphole computer derives position information based upon acceleration information and angular rate information. Kalman estimation techniques are used to compensate for system errors. 25 figures.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Sep 08 00:00:00 EDT 1982},
month = {Wed Sep 08 00:00:00 EDT 1982}
}