BORE HOLE LOGGING DEVICE

• US 3,845,569 A
• Filed: 02/09/1972
• Issued: 11/05/1974
• Est. Priority Date: 02/09/1972
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Gosta Roosman, Hubert Josef Otte
• Inventors: Otte, Hubert Josef, Roosman, Gosta
• Primary Examiner(s): Prince, Louis R.
• Assistant Examiner(s): Phillips, Charles E.
• Application Number:
  US05/224,861
• Time in Patent Office: 1,000 Days
• Field of Search: 33/312,313
• US Class Current: 33/312
• CPC Class Codes: E21B 47/0236 using a pendulum
• CPC Class Codes: G01C 19/02 Rotary gyroscopes

Abstract

A bore hole logging device employing an inclination pendulum device, and means for electrically sensing the position of the pendulum device, such pendulum device and sensing means being mounted on a freely rotatable housing or platform within the instrument which is weighted to adopt a constant uniform orientation within the bore hole. A further form of the invention may incorporate an additional reference pendulum to determine any deviations of the movable platform. A further form of the invention will incorporate a gyroscopic device also mounted on the rotatable housing or platform, and means for electrically sensing deviations between the azimuth bearing of the gyroscopic device and the azimuth bearing of the instrument.

Claims

1. A bore hole logging device of the type which is intended to be introduced into a bore hole, and passed therealong to determine the attitude of the bore hole at spaced intervals, without repeatedly withdrawing the device from the bore hole to obtain readings at each station therealong, said device comprising:

casing means adapted to be attached to means such as a cable, drill rods or the like, said casing defining a longitudinal axis;

mounting means movably located within said casing, and being rotatable about said longitudinal axis of said casing freely and independently of movement of said casing, said mounting means being constructed and weighted to define a centre of gravity thereof offset with respect to said longitudinal axis, whereby to bias said mounting means into a predetermined orientation with respect thereof when said longitudinal axis is appreciably inclined relative to the vertical;

inclination pendulum means mounted on said mounting means, said pendulum means being swingable about a swing axis transverse to said longitudinal axis of said device, and so located that said swing axis of said pendulum is normally located horizontal when said mounting means is located in said predetermined orientation;

sensing means associated with said inclination pendulumfor sensing the inclination thereof relative to said mounting means, thereby to determine the inclination of said logging device within a bore hole;

secondary reference pendulum means mounted on said mounting means, and swingable about a swing axis coincident with the longitudinal axis of said device, and sensing means for sensing the position thereof with reference to said mounting means, thereby to provide a check on the rotational position of said mounting means.

2. A bore hole logging device as claimed in claim 1 wherein said mounting means consists of an elongate body of generally semi-cylindrical shape along a major portion of its length, and recess means formed therein for reception of a portion of said pendulum therein in freely swingable relationship thereto, and including bearing means located spaced apart along said body, and fitting within said casing means whereby to mount said body within said casing means in freely rotatable relation thereto.

3. A bore hole logging device as claimed in claim 1 wherein said mounting means comprises an elongate body of predetermined density and specific gravity, and weight means incorporated in said body of greater specific gravity than said body, said weight means being offset with respect to said longitudinal axis of rotation of said mounting means.

4. A bore hole logging device as claimed in claim 1 wherein said pendulum comprises a generally cylindrically shaped body, said swing axis of said pendulum being located along the central axis of said cylindrical shaped body, said cylindrical shaped body being weighted and constructed so as to define a centre of gravity thereof which is offset with respect to said swing axis.

5. A bore hole logging device as claimed in claim 1 wherein said sensing means includes an electrical conductor member of arcuate shape, mounted on one side of said pendulum, concentric with the swing axis thereof, and electrical connection means connected to each end of said conductive member, forming the same into a potentiometer, and means for contacting and releasing said conductor member whereby to sense the inclination of said pendulum as aForesaid.

6. A bore hole logging device as claimed in claim 1 including electrically operable contact arm means forming part of said sensing means, and operable to swing into and out of contact with said pendulum.

7. A bore hole logging device of the type which is intended to be introduced into a bore hole, and passed therealong to determine the attitude of the bore hole at spaced intervals, without repeatedly withdrawing the device from the bore hole to obtain readings at each station therealong, said device having a longitudinal X axis and transverse Y and Z axes perpendicular to one another and comprising;

casing means adapted to be attached to means such as a cable, drill rods or the like, said casing defining said longitudinal X axis;

mounting means movably located within said casing, and being rotatable about said longitudinal axis of said casing freely and independantly of movement of said casing, said mounting means being constructed and weighted to define a centre of gravity thereof offset with respect to said longitudinal X axis, whereby to bias said mounting means into a predetermined orientation with respect thereof when said longitudinal X axis is appreciably inclined relative to the vertical;

inclination pendulum means mounted on said mounting means, said pendulum means being swingable about a swing axis transverse to said longitudinal X axis and parallel to said Y axis of said device, and so located that said swing axis of said pendulum is normally located horizontal when said mounting means is located in said predetermined orientation;

inclination sensing means associated with said pendulum for sensing the inclination thereof relative to said mounting means, thereby to determine the inclination of said logging device within a bore hole;

gyro means mounted on said mounting means, and adapted to maintain a constant orientation regardless of movement thereof;

gimbal bearing means supporting said gyro means on said mounting means, whereby said gyro may maintain said constant orientation in all positions of said device;

azimuth sensing means associated with said gyro means for sensing deviation of the aximuth of said mounting means relative to said gyro means;

secondary reference pendulum means mounted on said mounting means, and swinging about a swing axis coincident with the longitudinal axis of said device, and, sensing means for sensing the position thereof with reference to said mounting means, thereby to provide a check on the rotational position of said mounting means.

8. A bore hole logging device as claimed in claim 7 wherein said mounting means consists of an elongate body of generally semi-cylindrical shape along a major portion of its length, and recess formed therein for reception of a portion of said pendulum therein in freely swingable relationship thereto, and including bearing means located spaced apart along said body, and fitting within said casing means whereby to mount said body within said casing means in freely rotatable relation thereto.

9. A bore hole logging device as claimed in claim 7 wherein said mounting means comprises an elongate body of predetermined density and specific gravity, and weight means incorporated in said body of greater specific gravity than said body, said weight means being offset with respect to said longitudinal axis of rotation of said mounting means.

10. A bore hole logging device as claimed in claim 7 wherein said pendulum comprises a generally cylindrically shaped body having a central axis concentric therewith and wherein said swing axis of said pendulum is located along the central axis of said cylindrically shaped body being weighted and constructed so as to define a centre of gravity thereof which is offset with respect to said swing axis.

11. A bore hole logging device as claimed in claim 7 wherein said inclination sensing means includes an electrical conductor member of arcuate shape, mounted on one side of said pendulum, concentric with the swing axis thereof, and electrical connection means connected to each end of said conductive member, forming the same into a potentiometer, and means for contacting and releasing said conductor member whereby to sense the inclination of said pendulum as aforesaid.

12. A bore hole logging device as claimed in claim 7 including electrically operable contact arm means forming part of said inclination sensing means, and operable to swing into and out of contact with said pendulum.

13. A bore logging device as claimed in claim 7 wherein said reference pendulum means is swingable about a swing axis coincident with the longitudinal X axis of said device sensing means associated with said reference pendulum means for sensing the inclination thereof relative to said mounting means, thereby to provide a check on the rotational position of said mounting means.

14. A bore hole logging device as claimed in claim 7 including an outer gimbal shell means rotatably mounted on said mounting means for swinging about the Y axis transverse to the longitudinal X axis of said device, and being weighted whereby to define a centre of gravity thereof which is offset with respect to said rotational axis of said outer shell, whereby to bias said outer shell into a predetermined orientation about its said rotational axis;

intermediate shell means within said outer shell means rotatably mounted therein for swinging about the Z axis perpendicular to the longitudinal X axis and the transverse Y axis of said device;

sensing means within said outer shell means for sensing swinging movement of said intermediate shell means about said Z axis relative to said outer shell means, and, inner shell means rotatably mounted within said intermediate shell means for swinging about an axis coincident with the longitudinal X axis of said device, when said intermediate shell means is rotated to bring said inner shell axis into coincidence therewith, said gyro means being supported within said inner shell means.

15. A bore hole logging device as claimed in claim 14 including electrical conductor members located around the exterior of said outer shell, and contact means mounted on said mounting means and extending into contact therewith.

16. A bore hole logging device as claimed in claim 14 including electrical conductor means located around said intermediate shell means concentrically with said Z axis of rotation thereof, said sensing means on said outer shell means contacting said conductor means for sensing the position thereof.