Claims
- 1. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving a drill bit connected sensor having an axis coincident along a well borehole between first and second selected positions to form survey data at said first and second positions, wherein said positions are located within a non vertical section of said well borehole; (b) positioning a rate gyro in said sensor wherein said rate gyro forms rate gyro output signals indicative of measured angular rate at said first and second positions; (c) positioning in said sensor first and second accelerometers at a right angle therebetween wherein said accelerometers define a transverse plane to the axis of said sensor; and forming accelerometer output signals from said first and second accelerometers indicative of values sensed thereby at said first and second positions in said well borehole; (d) storing gyro data representative of said rate gyro output signals, relative to a reference azimuth measured by said rate gyro with said sensor stationary at said first position and second position along the well borehole; (e) forming stored accelerometer data representative of said accelerometer output signals, relative to a reference inclination measured by said accelerometers at said first position and second position along the well borehole; and (f) converting said stored rate gyro and accelerometer data into a plot of well borehole azimuth between said first and second positions.
- 2. The method of claim 1 wherein said sensor is an elongate collar and including the step of moving said collar along the well borehole in a drill string and moving said collar between said first and second positions.
- 3. The method of claim 1 wherein said rate gyro is initially oriented to define an axis thereof coincident with the axis of said sensor, and forming resolved X and Y components of movement of said rate gyro after moving from said first to said second position.
- 4. The method of claim 1 wherein said sensor is connected in a drill string in said well borehole and said drill string moves said sensor in said well borehole and movement of said sensor is measured as a function of time.
- 5. The method of claim 1 wherein said rate gyro is provided with first and second rate sensors at right angles for forming said rate gyro signals in X and Y axes with respect to the Z axis of the rate gyro, and further including the step of positioning the rate gyro so that the Z axis thereof coincides with said sensor, and subsequently calculating azimuth from said rate gyro.
- 6. The method of claim 1 wherein said first and second positions are in a well borehole inclined by a specified angle from the vertical.
- 7. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving an elongate drill collar having an axis coincident along a well borehole between first and second selected positions to form a survey connected between first and second positions wherein said first position is located within a non vertical section of said well borehole; (b) positioning a rate gyro in said drill collar wherein said rate gyro forms output signals indicative of measured angular rate at said first and second positions; (c) positioning in said drill collar first and second accelerometers at a right angle therebetween wherein said accelerometers define a transverse plane to the axis of said collar, and forming outputs from said first and second accelerometers indicative of values sensed thereby at said first and second positions in said well borehole and relative to a reference inclination; (d) converting data representative of the outputs of said rate gyro and said accelerometers including said first and second positions along the well borehole to determine well borehole inclination; and (e) recording a plot of well borehole inclination to form a plot through said first and second positions.
- 8. The method of claim 7 wherein said drill collar is an elongate cylindrical pipe and including the step of moving said collar along the well borehole between said first and second positions to obtain azimuth and depth at said fist and second positions.
- 9. The method of claim 8 wherein said rate gyro is initially oriented to define an axis thereof coincident with the axis of said drill collar, and forming resolved X and Y components of movement of said rate gyro in said collar while at said first and second positions.
- 10. The method of claim 7 wherein said drill collar is suspended on a drill string in said well borehole and said wireline is moved downwardly in said well borehole and movement of said collar is measured as a function of time to form a record thereof.
- 11. The method of claim 7 wherein said rate gyro is provided with first and second rate sensors at right angles for forming gyro rate output signals in X and Y axes with respect to the Z axis of the rate gyro, and further including the step of restoring the rate gyro so that the Z axis thereof coincides with said drill collar, and subsequently calculating well borehole azimuth with respect to a reference azimuth measured with said rate gyro and with said sensor stationary at said first position.
- 12. The method of claim 11 wherein said first and second positions are in a well borehole inclined by a specified angle from the vertical.
- 13. The method of claim 7 wherein said first and second positions are in a well borehole inclined by a specified angle from the vertical.
- 14. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving an elongate drill collar having an axis coincident therewith along a well borehole to first and second selected positions to form a survey at said first and second positions, wherein inclination of said well borehole at said first position is greater than about 15 degrees; (b) positioning a rate gyro in said drill collar wherein said rate gyro forms output signals indicative of measured angular rate at said first and second positions; (c) positioning in said drill collar first and second accelerometers at a right angle therebetween wherein said accelerometers define a transverse plane to the axis of said drill collar; and forming outputs from said first and second accelerometers indicative of values sensed thereby at first and second positions in said well borehole with respect to a reference inclination at said first position; (d) forming stored data representative of the outputs of said rate gyro with respect to a reference azimuth at said first position and said accelerometers at said first and second positions along the well borehole to determine well borehole azimuth and inclination; and (e) recording a plot of well borehole azimuth and inclination at said first and second positions.
- 15. The method of claim 14 wherein said housing is an elongate drill collar and including the step of moving said collar along the well borehole and moving said collar to said first and second positions.
- 16. The method of claim 14 wherein said rate gyro is initially oriented to define an axis thereof coincident with the axis of said drill collar, and forming resolved X and Y components of movement of said rate gyro at said first and second positions.
- 17. The method of claim 16 wherein said drill collar is suspended on an elongate drill string in said well borehole and said drill string is moved downwardly in said well borehole and movement of said drill string is measured as a function of time to form a record thereof.
- 18. The method of claim 16 wherein said rate gyro is provided with first and second rate sensors at right angles for forming gyro rate output signals in X and Y axes with respect to the Z axis of the rate gyro, and further including the step of positioning the rate gyro so that the Z axis thereof coincides with said drill collar to direct said axis along said borehole, and determining azimuth from said rate gyro.
- 19. The method of claim 14 wherein said first and second positions are in a well borehole inclined by a specified angle from the vertical.
- 20. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving an elongate sensor along a well borehole at first and second selected positions to form a survey at said first and second positions, wherein inclination of said well borehole at said first position is greater than about 15 degrees; (b) positioning a rate gyro in said sensor wherein said rate gyro forms orthogonal output signals indicative of measured angular rate between said first and second positions; (c) positioning in said sensor first and second accelerometers at a right angle therebetween wherein said accelerometers define a transverse plane to the axis of said sensor; (d) measuring a reference azimuth and a reference inclination at said first position and computing and storing data representative of the outputs of said rate gyro relative to said reference azimuth and said accelerometers relative to said reference inclination at said first and second positions along the well borehole; and (e) converting the stored data into a plot of well borehole azimuth at said first and second positions.
- 21. The method of claim 20 wherein said sensor is an elongate cylindrical drill collar and including the step of moving said collar along the well borehole at said first and second positions.
- 22. The method of claim 21 including the step of detecting collar vibration, and measuring the collar position to fix in relative space one of said accelerometer resolved outputs.
- 23. The method of claim 22 including the step of creating a Z axis output.
- 24. The method of claim 22 including the step of detecting the absence of vibration.
- 25. The method of claim 20 including the step of resolving the gyro output data into a horizontal plane for measuring inclination from the gyro data.
- 26. An apparatus comprising:(a) an elongate drill collar having an axis along the length thereof; (b) a motor in a housing for rotating a shaft extending along said collar; (c) a rate gyro supported by said collar and axially aligned within said collar and connected to said shaft for rotation thereby; (d) a pair of accelerometers defining an X and Y plane wherein said pair are at right angles, and are rotated by said motor shaft; (e) a signal processor connected to said rate gyro and said pair of accelerometers to process signals therefrom to form a survey of a well borehole, wherein said signal processor (i) forms a ratio of X and Y components of outputs of said accelerometers projected onto said X and Y planes, and (ii) combines X and Y outputs from said rate gyro with a function of said ratio thereby correcting said ratio for any non gravity acceleration effects and yielding a relative borehole inclination; and (f) a control for said signal processor to start operation thereof so that said processor forms a survey at first and second locations in said well borehole, wherein inclination of said well borehole at said first location is greater than about 15 degrees.
- 27. The apparatus of claim 26 wherein said control and said signal processor forms a survey of the well borehole beginning from a specified angle with respect to the vertical and relating said relative borehole inclination thereto.
- 28. The apparatus of claim 26 wherein said control responds to an angular change with respect to vertical in excess of a selected angle.
- 29. The apparatus of claim 26 wherein said gyro is rotated about said collar axis and said pair of accelerometers defines a plane at a non normal angle with respect to said axis.
- 30. The apparatus of claim 29 wherein said motor shaft is parallel to said drill collar axis at said rate gyro to mount said gyro for axial rotation, and said shaft is angled to said pair to define a non normal plane for said pair with respect to said housing axis.
- 31. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving an elongate sensor along a well borehole at first and second selected positions to form a survey at said first and second positions, wherein said first position is located within a non vertical section of said well borehole; (b) positioning a rate gyro in said sensor wherein said rate gyro forms orthogonal output signals indicative of measured angular rate at said first and second positions; (c) positioning in said sensor first and second accelerometers at a right angle therebetween wherein said accelerometers define a transverse plane to the axis of said sensor; (d) measuring gravity induced signals from said first and second accelerometers at the first position and determining therefrom a vector component describing the first position wherein the component includes well borehole inclination; (e) measuring at the first position a vector component describing sensor azimuth; (f) moving the sensor along the well borehole to the first and a second position in the well borehole; (g) storing data representing the inclination and azimuth at first and second positions; (h) measuring a reference azimuth and a reference inclination at said first position and computing and storing data representative of the output of said rate gyro relative to azimuth; (i) storing data representative of said accelerometers relative to inclination; and (j) converting the stored data into a plot of well borehole azimuth at said first and second positions.
- 32. The method of claim 31 including the step of measuring travel of said sensor along the well borehole at the first and second positions.
- 33. The method of claim 31 including the step of measuring sensor rotation as indicated by signals from said accelerometers.
- 34. The method of claim 31 including the step of measuring data from said rate gyro indicative of relative rotation of said sensor in space from said first position.
- 35. A method of conducting an oil well survey along a well borehole comprising the steps of:(a) moving an elongate sensor along a well borehole at first and second selected positions along the well borehole to form a borehole survey at said first and second positions, wherein said first position is located within a non vertical section of said well borehole; (b) measuring angular rate of the sensor on movement between said first and second positions; (c) placing first and second accelerometers at a right angle in said sensor wherein said accelerometers define a transverse plane to axis of said sensor; (d) measuring gravity induced signals from said first and second accelerometers at the first and second positions; (e) determining the well borehole inclination; (f) determining a vector component describing sensor azimuth; (g) moving the sensor along the well borehole to the first and a second position in the well borehole; (h) storing data representing the inclination and azimuth at said first and second positions; and (i) converting the stored data into a plot of well borehole azimuth at said first and second positions.
- 36. The method of claim 35 including the step of measuring linear travel of said sensor along the well borehole at the first and second positions.
- 37. The method of claim 36 including the step of measuring rotation as indicated by signals from said accelerometers.
- 38. The method of claims 35 including the step of measuring data from said rate gyro indicative of relative rotation in space from said first position.
- 39. A method of conducting an oil well survey comprising the steps of:(a) positioning a sensor in a well borehole to conduct a survey; (b) positioning a gyro in said sensor wherein said gyro forms orthogonal output signals responsive to gyro operation with sensor movement along said well borehole movement; (c) positioning two orthogonal accelerometers in a plane traverse to said sensor to form accelerometer output signals; (d) defining from said orthogonal accelerometer signals tool high side at a first time, wherein said sensor is located within a non vertical section of said well borehole at said first time; (e) determining at the first time the position of the gyro as indicated by the output signals of the gyro; and (f) moving the sensor along the well borehole from the first time to a second time and determining between said first and second times rotation of the sensor around an axis along the well borehole in response to said output signals.
Parent Case Info
This is a continuation Ser. No. 09/170,534 filed Oct. 13, 1998 now abandoned, which is a continuation-in-part of application Ser. No. 08/797,785 filed on Feb. 7, 1997 now U.S. Pat. No. 5,821,414.
US Referenced Citations (11)
Continuations (1)
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09/170534 |
Oct 1998 |
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10/140431 |
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Continuation in Parts (1)
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08/797785 |
Feb 1997 |
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09/170534 |
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