Inertial borehole survey system

• US 4,537,067 A
• Filed: 11/09/1983
• Issued: 08/27/1985
• Est. Priority Date: 11/18/1982
• Status: Expired due to Fees

• Current Assignee: Wilson Industries LP (Schlumberger NV)
• Original Assignee: Wilson Industries LP (Schlumberger NV)
• Inventors: Howatt, John R., Spiegel, Leo, Masters, Richard M., Sharp, Harper E., Walker, Gary E., Frey, Elmer J.
• Primary Examiner(s): MYRACLE, JERRY
• Application Number:
  US06/535,281
• Time in Patent Office: 657 Days
• Field of Search: 73/151, 73/152, 73/154, 73/431, 374/136, 33/304, 33/312, 367/35
• US Class Current: 73/152.13
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism

Abstract

An inertial borehole survey system is disclosed. The survey system of the present invention includes a probe suitable for insertion into a borehole. The probe includes a plurality of temperature sensitive inertial measuring instruments which are utilized to survey the borehole during the descent or ascent of the probe. Accuracy of these instruments is maintained by enclosing the instruments in a thermal insulating package and by providing a mass of isothermal heat absorbing material which exhibits a phase change at a temperature well above most ambient temperatures. In a preferred embodiment of the present invention, a heat absorbing material is utilized which exhibits a phase change at a temperature of 116° F. The probe also includes a longitudinal air passage which permits ambient temperature air to be utilized to cool the isothermal heat absorbing material by passing air through the length of the probe. Currently the instrument cluster is mounted on a member formed of a single billet of metal to form a thermally conductive, small diameter, stiff structure which permits the inertial measurement instruments to be spaced longitudinally in a cluster in order to minimize the diameter to approximately the largest diameter of any single instrument and yet which permits heat generated by the instruments to be absorbed by the heat absorbing material.

Claims

1. A probe for insertion in a borehole for making measurements therein comprising:

an elongated outer housing forming a pressure vessel;

a temperature sensitive instrument means disposed in said housing;

a thermal insulating member disposed in said housing and defining a chamber in which said instrument means is disposed, said member forming a thermal barrier between said housing and said instrument means; and

isothermal heat absorbing means disposed in said housing and in heat flow receiving communication with said instrument means, said heat absorbing means including a quantity of material for absorbing heat in said chamber, said material being adapted to undergo a phase change at a phase change temperature which will maintain said instrument means in a predetermined temperature range for a predetermined time period, said phase change temperature being substantially above most ambient temperatures wherein an ambient temperature fluid may be utilized to cool said material to a temperature below said phase change temperature.

2. The probe set forth in claim 1 including:

means for cooling said phase change material to reject heat absorbed by said material during said period, said cooling means including passage means in said housing opening into said chamber and means for providing a flow of cooling fluid in heat exchange with said heat absorbing means to change the phase of said material to condition said heat absorbing means for absorbing heat in said chamber to maintain said instrument means in said temperature range during a borehole measurement period.

3. The probe set forth in claim 2 wherein:

said housing includes means forming closure members at opposite ends thereof, first passage means at one end of said housing adapted to be in communication with said chamber through one of said closure members and second passage means in the opposite closure member, said first passage means being adapted to be connected to a source of cooling fluid comprising conditioned air for conducting said conditioned air through said housing to cool said material to condition said heat absorbing means for absorbing heat during a measurement period of said probe.

4. The probe set forth in claim 2 wherein:

said insulating member comprises an elongated vacuum sleeve including inner and outer tubular walls defining a substantially annular vacuum chamber, said sleeve having openings at each end thereof, and thermal insulating plug means for closing said openings in said sleeve, respectively, said plug means including passage means for conducting cooling fluid to and from said chamber.

5. A probe for insertion in a borehole for making measurements therein comprising:

an elongated tubular outer housing forming a closed pressure vessel;

means forming a thermal barrier between the exterior of said housing and a chamber within the interior of said housing;

instrument means disposed in said chamber, said instrument means including electrical circuit means including a member for supporting circuit elements of said circuit means;

isothermal heat absorbing means disposed in said chamber and in heat flow communication with said circuit means, said heat absorbing means comprising at least one container including a quantity of material operable to change from a first phase to a second phase at a predetermined temperature to maintain a predetermined operating temperature condition of said probe;

said predetermined temperature being substantially above most ambient temperatures wherein an ambient temperature fluid may be utilized to cool said material.

6. The probe set forth in claim 5 wherein:

said means forming a thermal barrier includes an elongated vacuum sleeve disposed in said housing and defining said chamber.

7. The probe set forth in claim 5 wherein:

said circuit means includes a plurality of said members comprising respective circuit boards extending within said chamber, each of said circuit boards being in conductive heat flow communication with a respective one of said containers for transferring heat generated by said circuit means to said material to maintain a predetermined operating temperature condition of said instrument means.

8. The probe set forth in claim 7 wherein:

said circuit boards are arranged in said chamber to provide for conducting a flow of cooling fluid through said chamber, over a heat transfer surface of said containers and out of said chamber for cooling said material.

9. The probe set forth in claim 8 wherein:

said circuit boards are arranged in said chamber whereby said containers are disposed between said circuit boards and said means forming said thermal barrier.

10. The probe set forth in claim 5 wherein:

said cooling fluid is a gas and said probe includes means for introducing said cooling fluid to said chamber and venting cooling fluid from said chamber to purge said chamber of heated gases in said chamber.

11. The probe set forth in claim 10 wherein:

said probe includes battery means disposed in a compartment in communication with said chamber and between said means for introducing said cooling fluid to and venting said cooling fluid from said chamber, respectively, whereby said cooling fluid is operable to vent said battery compartment during cooling of said material.

12. The probe set forth in claim 5 wherein:

said probe includes a source of conditioned cooling air including means operable to provide said conditioned air to said chamber at a temperature below the phase change temperature of said material and at a temperature for effecting the onset of phase change of said material from said first phase to said second phase.

13. A probe for insertion into a borehole for making measurements in said borehole, said probe including:

an elongated cylindrical housing comprising a pressure vessel having opposed head members, at least one of said head members being detachable from said housing to provide access to the interior of said housing;

an elongated thermal insulating member insertable in said housing and providing a thermally insulated chamber,

electrical instrument means disposed in said insulated chamber;

means for maintaining said instrument means in a preselected operating temperature range, said means comprising a plurality of spaced apart containers disposed in said chamber, each of said containers including a quantity of material operable to absorb latent heat in changing from a first phase to a second phase to maintain said operating temperature range of said instrument means;

a cooling fluid inlet passage in said housing, and means forming a cooling fluid outlet passage in said housing to provide for circulating cooling fluid through said chamber to cause said material to change from said second phase to said first phase to condition said probe for operation of said instrument means.

14. The probe set forth in claim 13 including:

electrical circuit board means in said chamber, one of said containers being in conductive heat flow communication with said circuit board means, and an elongated instrument housing in said chamber, at least one of said containers being in conductive heat flow communication with said instrument housing for maintaining said instrument housing at a predetermined temperature.

15. The probe set forth in claim 14 wherein:

said instrument housing includes respective ones of said containers in conductive heat flow communication with said instrument housing and at opposite longitudinal ends of said instrument housing, respectively, whereby heat is conducted along the outer surface of said instrument housing toward said opposite ends and to said containers.

16. The probe set forth in claim 15 wherein:

said instrument housing is disposed in said chamber between a first electrical circuit including circuit board means and a second electrical circuit including circuit board means, said heat absorbing means including respective containers in conductive heat flow relationship with said first and second electrical circuits, said containers in heat flow communication with said instrument housing and said containers in heat flow communication with said electrical circuits being disposed in said chamber for heat exchange with said cooling fluid being circulated through said chamber.

17. The probe set forth in claim 16 including:

respective heat absorbing containers at opposite ends of said chamber and disposed for heat exchange communication with said cooling fluid being circulated through said chamber.

18. The probe set forth in claim 17 wherein:

said inlet and outlet passages are disposed at opposite ends of said housing, respectively.

19. The probe set forth in claim 13 wherein:

said housing is formed in at least two sections, each of said sections including a thermal insulating member providing a thermally insulated chamber, respectively, at least one of said containers being disposed in each of said chambers, means on each of said housing sections for coupling said housing sections in end to end relationship, and fluid conducting passage means in said coupling means for conducting cooling fluid from one housing section to the other, one of said housing sections including said inlet passage at one end thereof and the other of said housing sections including said means forming said outlet passage at the end of said other housing section opposite said coupling means.

20. A method for preparing a probe for insertion in a borehole to make measurements in said borehole, said probe comprising a housing forming a closed pressure vessel, instrument means disposed in said housing, said instrument means being adapted to operate in a predetermined temperature range, isothermal heat absorbing means disposed in said housing including container means containing a quantity of material operable to undergo a phase change from a first phase to a second phase at a temperature which will maintain said instrument means in said operating temperature range, said probe further including means for cooling said heat absorbing means to change said material from said second phase to said first phase, said method comprising:

circulating cooling fluid in heat exchange relationship with said material at a temperature of said cooling fluid which will change said material from said second phase to said first phase;

measuring the temperature in said probe to determine if said material has changed to said first phase; and

increasing the temperature of said cooling fluid to cause the temperature of said heat absorbing means to increase to the phase change temperature to stabilize the temperature of said instrument means in said operating temperature range preparatory to making measurements with said instrument means.

21. The method set forth in claim 20 wherein:

said cooling fluid is a gas, said housing includes means for circulating said cooling fluid through said housing and in heat exchange with said heat absorbing means, and said method includes the step of circulating said cooling fluid through said housing to purge gases from the interior of said housing and to cool said heat absorbing means and said instrument means.

22. The method set forth in claim 20 wherein:

said method includes the step of selecting a material for said isothermal heat absorbing means which will undergo said phase change at a temperature greater than the anticipated ambient temperature at which said probe is prepared for making said measurements.

23. A probe for insertion in a borehole for making measurements in said borehole, said probe including:

an elongated housing forming a closed pressure vessel;

a thermal insulating member insertable in said housing and including means forming a tubular wall defining an insulated interior chamber;

an instrument assembly removably insertable in said insulating member, said instrument assembly including support means adapted for supporting said instrument assembly in forcible engagement with said wall for securing said assembly in said member, said support means including at least one support unit including radially extendable support members forcibly engageable with said wall, and means for moving said support members between a radially extended and retracted condition, said means for moving said support members being operable from one end of said instrument assembly.

24. The probe set forth in claim 23 wherein:

said support unit comprises a pair of spaced apart support plates, and said support member includes means forming resilient band means interposed between and engageable by said plates, said band means including a distal end radially extendable in response to deformation of said band means by moving said plates toward each other to axially compress said band means.

25. The probe set forth in claim 27 wherein:

said band means comprises a plurality of circumferentially spaced and radially extending band members disposed between said support plates.

26. The probe set forth in claim 24 wherein:

said means for moving said support means include a plurality of circumferentially spaced elongated tie rods connected to a member of said instrument assembly and to means engageable with one of said support plates.

27. The probe set forth in claim 26 wherein:

said instrument assembly includes a plurality of said support units spaced apart on said instrument assembly and engageable with said wall.

28. The probe set forth in claim 23 wherein:

said instrument assembly comprises a rotatable assembly including an instrument housing supported by bearing means disposed at opposed ends of said instrument housing, respectively, said bearing means being secured in said member by respective ones of said support units, and coupling means interposed between said bearing means and said instrument housing and adapted to accommodate misalignment of said bearing means with respect to said instrument housing.

29. The probe set forth in claim 28 wherein:

one of said coupling means is adapted to accommodate axial elongation and contractions of said rotatable assembly and the other of said coupling means is adapted to accommodate skew misalignment of said instrument housing with respect to said bearing means.

30. A probe for insertion in a borehole for making measurements therein, said probe comprising:

an elongated cylindrical housing forming a closed pressure vessel and a removable head member of said housing for gaining access to the interior thereof;

means forming a thermal insulating sleeve in said housing, said sleeve including an inner wall defining an interior chamber;

an elongated instrument assembly adapted to be removably insertable in said sleeve, said instrument assembly including a first electrical circuit module including support means releasably engageable with said inner wall of said sleeve, a second electrical circuit module spaced from said first module and including support means releasably engageable with said inner wall of said sleeve, and a rotatable instrument housing interposed between said modules and supported by spaced apart bearing means, said bearing means being at least partially supported on said sleeve by respective ones of support means of said first and second modules.

31. The probe set forth in claim 30 including:

means accessible from opposed ends of said instrument assembly in said sleeve for securing said modules and said bearing means in said sleeve by actuating said support means to engage said inner wall.

32. The probe set forth in claim 30 wherein:

said bearing means comprise respective electrical slip ring assemblies including stator members supported in said sleeve by respective ones of said support means, and slip ring assemblies include respective rotor members connected in supportive relationship to said instrument housing, and said instrument assembly includes electrical conductor means extending between said slip ring assemblies and said modules, respectively.

33. The probe set forth in claim 32 wherein:

at least one of said modules includes a plurality of circuit boards extending between respective ones of said support means, said circuit boards being at least partly supported by spaced apart and coextensive tie rods for actuating said support means to releasably engage said wall.

34. The probe set forth in claim 33 including:

a plurality of circuit boards in at least one of said modules arranged in an array providing a central longitudinal passage through said chamber, said conductor means extending through said central passage between said circuit boards and said slip ring assembly adjacent to said one module.

35. The probe set forth in claim 33 wherein:

said support means comprise a plurality of spaced apart support members including radially extendable means engageable with said wall, said tie rods extending between said support members and cooperable with means movable axially relative to said tie rods to cause said radially extendable means to move into gripping engagement with said wall.

36. A probe for insertion in a borehole for making measurements therein, said probe comprising:

an elongated cylindrical housing forming a closed pressure vessel and a removable head member of said housing for gaining access to the interior thereof;

means in said housing forming an inner cylindrical wall defining an interior chamber;

an elongated instrument assembly adapted to be removably insertable in said chamber, said instrument assembly including a first electrical circuit module adapted to be supported in said chamber, a second electrical circuit module spaced from said first module and adapted to be supported in said chamber, and a rotatable instrument housing interposed between said modules and supported by spaced apart bearing means; and

said bearing means comprising respective electrical slip ring assemblies including stator members supported in said chamber by respective support means releasably engageable with said wall, said slip ring assemblies including respective rotor members connected in supportive relationship to opposite ends of said instrument housing, said instrument assembly including electrical conductor means extending between said slip ring assemblies and said modules, respectively, and electrical conductor means extending between said instrument housing and said slip ring assemblies, respectively.

37. The probe set forth in claim 36 including:

coupling means interposed between said bearing means and said instrument housing and adapted to accommodate misalignment of said bearing means with respect to said instrument housing.

38. The probe set forth in claim 36 wherein:

one of said coupling means is adapted to accommodate axial elongation and contraction of said instrument housing and the other of said coupling means is adapted to accommodate skew misalignment of said instrument housing with respect to said bearing means.