Borehole surveying
AssigneeSmart Stabilizer Systems Limited
InventorsAnthony W. Russell, Michael K. Russell
Life of this patent
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Abstract
The invention relates to a method and an apparatus for use in surveying boreholes. The method of the invention comprises the following steps: providing an instrument package in a leading end of a drillstring, the instrument package comprising first and second single-axis sensors mounted for rotation with the drillstring about the rotational axis of the drillstring, the first sensor being an accelerometer and the second sensor being a magnetic fluxgate or a rate gyro; rotating the drillstring; deriving from the first sensor the inclination angle of the drillstring at the instrument package; and deriving from the second sensor the azimuth angle of the drillstring at the instrument package.
Claims12
A method of surveying boreholes, comprising:
- providing an instrument package in a leading end of a drillstring, said instrument package comprising first and second single-axis sensors mounted for rotation with the drillstring about the rotational axis of the drillstring, the first sensor being an accelerometer and the second sensor being a magnetic fluxgate or a rate gyro;
- rotating the drillstring;
- deriving solely from the first sensor the inclination angle of the drillstring at the instrument package;
- and
- deriving solely from the first sensor and the second sensor the azimuth angle of the drillstring at the instrument package.
An apparatus for use in surveying boreholes, the apparatus comprising:
- an instrument package adapted to be included in the leading end of drillstring, the instrument package comprising first and second single-axis sensors mounted for rotation with the drillstring about the rotational axis of the drillstring, the first sensor being an accelerometer and the second sensor being a magnetic fluxgate or rate-gyro;
- and
- computing means for deriving solely from the first sensor while the drillstring is rotating the inclination angle of the drillstring at the instrument package, and or deriving solely from the first sensor and the second sensor while the drillstring is rotating the azimuth angle of the drillstring at the instrument package.
Dependencies are inferred from the claim text.