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Claims  |
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What is claimed is:
1. Well bore apparatus comprising:
body means adapted for passage through a well bore;
driving means including a shaft member cooperatively arranged on said body
means and adapted to be alternatively rotated in opposite rotational
directions;
tool-positioning means including a tool-positioning member cooperatively
arranged on said body means and adapted for free movement back and forth
between a retracted position and an extended wall-engaging position; and
means cooperatively arranged on said body means for controlling the
movement of said tool-positioning member and including coupling means
operable in response to rotation of said shaft member in one of said
rotational directions for uncoupling said members so as to then release
said tool-positioning member for its said free movement and operable in
response to rotation of said shaft member in the other of said rotational
directions for releasably intercoupling said members so as to then return
said tool-positioning member to its said retracted position, said coupling
means having means operable upon return of said tool-positioning member to
its said retracted position for selectively restraining retrograde
movement of said tool-positioning member toward its said extended position
and releasable only upon rotation of said shaft member in said one
rotational direction to leave said tool-positioning member free for
movement between its said extended and retracted positions.
2. The well bore apparatus of claim 1 wherein said tool-positioning means
further include:
spring means cooperatively arranged and adapted to be at least further
energized upon movement of said tool-positioning member toward its said
retracted position for urging said tool-positioning member outwardly
toward its said extended position with a predetermined biasing force
commensurate with the degree of energization of said spring means.
3. The well bore apparatus of claim 1 wherein said tool-positioning means
further include:
spring means cooperatively mounted between said body means and said
tool-positioning member and adapted to be energized upon its movement
toward its said retracted position by the driving of said shaft member in
said other rotational direction, said spring means being operable whenever
said members are uncoupled for urging said tool-positioning member toward
its said extended position with a biasing force commensurate with the
degree of energization of said spring means.
4. The well bore apparatus of claim 1 wherein said means for selectively
restraining retrograde movement comprises ratchet means selectively
engageable with said shaft member as it is being driven in said other
rotational direction for releasably preventing retrograde rotation of said
shaft member in said one rotational direction and selectively releasable
in response to the driving of said shaft member in said one rotational
direction.
5. The well bore apparatus of claim 4 wherein said tool-positioning means
further include:
spring means cooperatively mounted between said body means and said
tool-positioning member and adapted to be energized upon return thereof
toward its said retracted position and then effective upon uncoupling of
said members for urging said tool-positioning member toward its said
extended position with a predetermined biasing force selected to move said
tool-positioning member outwardly at a controlled speed of travel.
6. The well bore apparatus of claim 5 wherein said biasing force provided
by said spring means is selected so that return of said tool-positioning
member toward its said extended position is at a lower travel speed than
said controlled speed of travel as said tool-positioning member is being
moved toward its said extended position by said biasing force.
7. Well bore apparatus comprising:
body means adapted for passage through a well bore;
driving means including a shaft member cooperatively arranged on said body
means and adapted to be alternatively rotated in opposite rotational
directions;
tool-positioning means including a tool-positioning member cooperatively
arranged on said body means and adapted for free movement back and forth
between a retracted position and an extended wall-engaging position;
means cooperatively arranged on said body means for controlling the
movement of said tool-positioning member and including coupling means
operable in response to rotation of said shaft member in one of said
rotational directions for uncoupling said members so as to then release
said tool-positioning member for its said free movement and operable in
response to rotation of said shaft member in the other of said rotational
directions for releasably intercoupling said members so as to then return
said tool-positioning member to its said retracted position, said coupling
means having means operable upon rotation of said shaft member in said
other rotational direction for selectively preventing counter-rotation of
said shaft member in said one rotational direction and selectively
releasable only upon rotation of said shaft member in said one rotational
direction for freeing said tool-positioning member for movement toward its
said extended position.
8. The well bore apparatus of claim 7 wherein said tool-positioning means
further include:
spring means cooperatively mounted between said body means and said
tool-positioning member and adapted to be energized upon return of said
tool-positioning member to its said retracted position to provide a
predetermined biasing force effective upon release of said
tool-positioning member for moving it toward its said extended position at
a predetermined speed of travel which is faster than the speed at which
said tool-positioning member is returned to its said retracted position.
9. The well bore apparatus according to any one of claims 1, 2, 7, 8, 3, 4,
5, or 6 wherein said driving means further include:
a selectively-reversible electrical motor on said body means and
cooperatively coupled to said shaft member for alternatively driving said
shaft member in either of its said opposite rotational directions.
10. Well bore apparatus comprising:
a tool body adapted for passage through a well bore;
tool-positioning means including at least one wall-engaging member, means
pivotally cnnecting said wall-engaging member to said tool body for
pivotal movement between a retracted position adjacent to said tool body
and an extended position spatially disposed away from said tool body, and
spring means cooperatively associated with said wall-engaging member and
adaptd to impose thereon a biasing force of predetermined magnitude
selected for pivoting said wall-engaging member toward its said extended
position at a predetermined speed of travel;
driving means including a shaft member cooperatively arranged on said tool
body and adapted to be alternatively driven in opposite rotational
directions; and
coupling means cooperatively arranged between said members operable upon
rotation of said shaft member in one of said rotational directions for
uncoupling said members so that only said spring means are then operative
for moving said wall-engaging member toward its said extended position at
said predetermined speed of travel and operable upon rotation of said
shaft member in the other of said rotational directions for releasably
intercoupling said members so as to return said wall-engaging member to
its said retracted position at a speed of travel that is less than said
predetermined speed of travel.
11. The well bore apparatus of claim 10 wherein said coupling means further
include:
means operable upon driving said shaft member in said other rotational
direction for selectively preventing retrograde movement of said
wall-engaging member toward its said extended position and operable upon
driving of said shaft member in said one rotational direction to release
said wall-engaging member for free movement between its said extended and
retracted positions.
12. The well bore apparatus of claim 10 wherein said spring means include:
at least one arcuately-configured leaf spring mounted between said tool
body and said wall-engaging member and adapted to be at least further
energized upon movement of said wall-engaging member toward its said
retracted position for developing said biasing force commensurate with the
degree of energization of said leaf spring to then urge said wall-engaging
member toward its said extended position.
13. The well bore apparatus of claim 12 wherein said coupling means further
include:
means operable only upon driving of said shaft member in said other
rotational direction for selectively halting retrograde movement of said
wall-engaging member away from its retracted position and operable only
upon driving of said shaft member in said one rotational direction for
releasing said wall-engaging member for movement toward its said extended
position in response to said biasing force.
14. The well bore apparatus of claim 10 wherein said coupling means further
include:
means operable upon rotation of said shaft member in said other rotational
direction for selectively preventing counter rotation of said shaft member
in said one rotational direction and selectively releasable only upon
rotation of said shaft member in said one rotational direction for freeing
said wall-engaging member for movement toward its said extended positions.
15. The well bore apparatus according to any one of claims 10, 11, 12, 13
or 14 wherein said driving means further include:
a selectively-reversible electrical motor on said tool body and
cooperatively arranged for alternatively driving said shaft member in
either of its said rotational directions.
16. Well bore apparatus comprising:
a tool body adapted for passage through a well bore;
tool-positioning means including at least one wall-engaging member, means
operatively connecting said wall-engaging member to said tool body for
movement back and forth between retracted and extended positions, and
spring means cooperatively arranged for acting on said wall-engaging
member with a biasing force of predetermined magnitude selected for moving
said wall-engaging member toward its said extended position at a
predetermined speed of travel;
driving means including a shaft member cooperatively arranged on said tool
body and adapted to be alternatively driven in opposite rotational
directions; and
coupling means cooperatively arranged on said tool body for selectively
intercoupling said members including a rotatable threaded shaft, a
threaded body operatively mounted on said threaded shaft and co-rotatively
secured in relation to said tool body for axial movement along said
threaded shaft as it is rotated, force-transmitting means coupling said
threaded body to said wall-engaging member and adapted for transferring
forces therebetween, and clutch means operable in response to rotation of
said shaft member in one of its said rotational directions for selectively
uncoupling said shaft member from said threaded shaft so that said
wall-engaging member will be released for movement toward its extended
position at said predetermined speed of travel and remain free for
movement back and forth between its said extended and retracted positions
upon passage of said tool body along a well bore, said clutch means also
being operable in response to rotation of said shaft member in the other
of its said rotational directions for selectively intercoupling said shaft
member to said threaded shaft so that the corresponding axial movement of
said threaded body therealong will be effective for returning said
wall-engaging member to its retracted position at a speed of travel less
than said predetermined speed of travel.
17. The well bore apparatus of claim 16 wherein said coupling means further
include:
ratchet means selectively engageable with said shaft member as it is being
driven in said other rotational direction for releasably preventing
retrograde rotation of said shaft member in said one rotational direction
and selectively releasable in response to the driving of said shaft member
in said one rotational direction.
18. The well bore apparatus of claim 16 wherein said clutch means include:
a first clutch member coupled to said threaded shaft, a second clutch
member cooperatively arranged for movement between two axially-spaced
operating positions, and cam means operatively coupling said second clutch
member to said shaft member and responsive to rotation thereof in said one
rotational direction for axially shifting said second clutch member to one
of its said operating positions where said clutch members are disengaged
and responsive to rotation of said shaft member in said other rotational
direction for axially shifting said second clutch member to the other of
its said operating positions where said clutch members are drivingly
engaged.
19. The well bore apparatus of claim 18 wherein said coupling means further
include:
ratchet means selectively engageable with said shaft member as it is being
driven in said other rotational direction for releasably preventing
retrograde rotation of said shaft member in said one rotational direction
when said clutch members are drivingly engaged and selectively releasable
in response to the driving of said shaft member in said one rotational
direction when said clutch members are disengaged.
20. The well bore apparatus according to any one of claims 16, 17, 18 or 19
wherein said driving means further include:
a selectively-reversible electrical motor on said tool body and
cooperatively coupled to said shaft member for alternatively driving said
shaft member in its said opposite rotational directions.
21. Well bore apparatus comprising:
body means adapted for passage through a well bore;
driving means on said body means and adapted for alternative rotation in
opposite rotational directions;
tool-positioning means including a plurality of wall-engaging members
cooperatively arranged at uniformly-spaced intervals around said body
means and respectively adapted for movement between retracted positions
adjacent to said body means and extended positions spaced outwardly from
said body means;
means cooperatively arranged on said body means for selectively controlling
the movements of said wall-engaging members between their said retracted
and extended positions and including coupling means between said
wall-engaging members and said driving means operable in response to
rotation of said driving means in one of said rotational for selectively
uncoupling said driving means from said wall-engaging members so that they
will be freed for movement between their said extended and retracted
positions in response to passage of said body means along a well bore and
operable in response to rotation thereof in the other of said rotational
directions for selectively intercoupling said driving means to said
wall-engaging members so as to bring them toward their said retracted
positions;
electrical transducer means on said body means and having a
selectively-variable electrical characteristic; and
transducer-actuating means coupled to at least one of said wall-engaging
members and operable upon movement thereof for proportionally varying said
electrical characteristic as a function of well bore diameter.
22. Well bore apparatus comprising:
body means adapted for passage through a well bore;
driving means on said body means and adapted for alternative rotation in
opposite rotational directions;
tool-positioning means including a plurality of wall-engaging members
cooperatively arranged at uniformly-spaced intervals around said body
means and respectively adapted for movement between retracted positions
adjacent to said body means and extended positions spaced outwardly from
said body means;
means cooperatively arranged on said body means for selectively controlling
the movements of said wall-engaging members between their said retracted
and extended positions and including coupling means between said
wall-engaging members and said driving means operable in response to
rotation of said driving means in one of said rotational directions for
seletively uncoupling said driving means from said wall-engaging members
so that they will be freed for movement between their said extended and
retracted positions in response to passage of said body means along a well
bore and operable in response to rotation thereof in the other of said
rotational directions for selectively intercoupling said driving means to
said wall-engaging members so as to bring them towards their said
retracted positions;
first and second electrical trnsducer means on said body means and
respectively having first and second selectively-variable electrical
characteristics; and
first and second transducer-actuating means respectively coupled to a first
one and to a second one of said wall-engaging members and selectively
operable upon their respective movements for proportionally varying said
first electrical characteristic as a function of well bore diameter in the
plane of movement of said first wall-engaging member and for
proportionally varying said second electrical characteristic as a function
of well bore diameter in the plane of movement of said second
wall-engaging member.
23. The well bore apparatus of claim 22 wherein said plane of movement of
said first wall-engaging members lies substantially at right angles to
said plane of movement of said second wall-engaging member.
24. The well bore apparatus according to any one of claims 21, 22 or 23
wherein said tool-positioning means further include:
spring means cooperatively arranged and adapted to be at least further
energized upon inward movement of said wall-engaging members toward their
said retracted positions for urging said wall-engaging members outwardly
toward their said extended positions with a biasing force commensurate
with the degree of energization of said spring means.
25. The well bore apparatus of claim 24 wherein said driving means further
include:
a selectively-reversible electrical motor operatively arranged to be
alternatively rotated in said opposite rotational directions.
26. The well bore apparatus according to any one of claims 21, 22 or 23
wherein said wall-engaging members are rigid arms and said
tool-positioning means further include:
means pivotally connecting each of said rigid arms to said body means, and
spring means cooperatively arranged and adapted to be at least further
energized upon pivotal movement of said rigid arms toward their said
retracted positions.
27. The well bore apparatus of claim 26 wherein said driving means further
include:
a selectively-reversible electrical motor operatively arranged to be
alternatively rotated in said opposite rotational directions.
28. The well bore apparatus according to any one of claims 21, 22 or 23
wherein said driving means further include:
a selectively-reversible electrical motor operatively arranged to be
alternatively rotated in said opposite rotational directions.
29. Well bore apparatus comprising:
a tool body adapted for passage through a well bore;
driving means including a shaft member cooperatively arranged on said tool
body and adapted to be alternatively driven in opposite rotational
directions;
tool-positioning means including a first pair of wall-engaging means on
diametrically-opposite first sides of said tool body and pivotally coupled
thereto for pivotal movement between retracted positions and extended
positions lying in a first plane of movement, a second pair of
wall-engaging means on diametrically-opposite second sides of said tool
body and pivotally coupled thereto for pivotal movement between retracted
and extended positions lying in a second plane of movement substantially
perpendicularly intersecting said first plane of movement along the
longitudinal axis of said tool body, and first and second spring means
cooperatively arranged and adapted for respectively urging said first and
second pairs of wall-engaging means toward their said extended positions
at predetermined speeds of travel; and
means cooperatively arranged on said tool body for selectively controlling
the independent movements of said first and second pairs of wall-engaging
means between their said retracted and extended positions and including
coupling means cooperatively arranged on said tool body for selectively
intercoupling said shaft member to said first and second pairs of
wall-engaging means including a rotatable threaded shaft, a threaded body
operatively mounted on said threaded shaft and co-rotatively secured in
relation to said tool body for producing axial movement of said threaded
body along said threaded shaft as it is rotated, force-transmitting means
coupling said threaded body to said first and second pairs of
wall-engaging means, and clutch means selectively operable upon rotation
of said shaft member in one of its said rotational directions for
uncoupling said shaft member from said threaded shaft so that said first
and second pairs of wall-engaging means will be released for movement
toward their extended positions at their respective predetermined speeds
of travel and be freed for movement back and forth between their said
extended and retracted positions upon passage of said tool body along a
well bore, said clutch means also being selectively operable upon rotation
of said shaft member in the other of its said rotational directions for
releasably coupling said shaft member to said threaded shaft so that upon
its rotation the corresponding axial movement of said threaded body
therealong will be effective for returning said first and second pairs of
wall-engaging means to their said retracted positions.
30. The well bore apparatus of claim 29 wherein said coupling means further
include:
ratchet means selectively engageable with said shaft member as it is being
driven in said other rotational direction for releasably preventing
retrograde rotation of said shaft member in said one rotational direction
and selectively releasable in response to the driving of said shaft member
in said one rotational direction.
31. The well bore apparatus of claim 29 wherein said clutch means include:
a first clutch member coupled to said threaded shaft, a second clutch
member cooperatively arranged for movement between axially-spaced
positions, and means operatively coupling said second clutch member to
said shaft member and responsive to rotation thereof in said one
rotational direction for shifting said second clutch member to one of its
said axial positions where said clutch members are disengaged and
responsive to rotation of said shaft member in said other rotational
direction for shifting said second clutch member to the other of its said
axial positions where said clutch members are drivingly engaged.
32. The well bore apparatus of claim 31 wherein said coupling means further
include:
ratchet means selectively engageable with said shaft member as it is being
driven in said other rotational direction for releasably preventing
retrograde rotation of said shaft member in said one rotational direction
when said clutch members are drivingly engaged and selectively releasable
in response to the driving of said shaft member in said one rotational
direction when said clutch members are disengaged.
33. The well bore apparatus of claim 29 further including:
first and second electrical transducer means on said tool body and
respectively having first and second selectively-variable electrical
characteristics; and
first and second transducer-actuating means respectively coupled to said
first and second pairs of wall-engaging means and selectively operable
upon their respective movements for proportionally varying said first and
second electrical characteristics respectively as a function of well bore
diameter in said first plane of movement and as a function of well bore
diameter in said second plane of movement.
34. The well bore apparatus of claim 29 wherein said first and second pairs
of wall-engaging means include first and second pairs of rigid arms; and
said first and second spring means are respectively cooperatively arranged
between said rigid members and said tool body to be at least further
energized upon movement of said rigid members toward their said retracted
positions.
35. The well bore apparatus according to any one of claims 29, 30, 31, 32,
33 or 34 wherein said driving means further include:
a selectively-reversible electrical motor operatively coupled to said shaft
member for alternatively driving it in its said opposite rotational
directions.
36. Well bore apparatus comprising:
body means adapted for passage through a well bore;
driving means including a shaft member cooperatively arranged on said body
means and adapted to be selectively rotated in opposite rotational
directions or to remain stationary;
tool-positioning means including a tool-positioning member cooperatively
arranged on said body means and adapted for free movement between a
retracted position and an extended wall-engaging position;
coupling means cooperatively arranged on said body means between said
driving means and said tool-positioning means for
releasing said tool-positioning means for its free movement in response to
rotation of said shaft member in a first direction;
retracting said tool-positioning means to said retracted position in
response to rotation of said shaft member in the second other direction;
and
preventing said tool-positioning means from moving from its retracted
position until said shaft member is rotated in said first direction. |
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Claims |
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Description |
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It will be appreciated that many so-called "wireline service" or
well-completion tools employ one or more mechanical devices which, during
the operation of the tool, require various kinds of controlled movements.
For instance, many wireline tools have one or more wall-engaging members
which must be selectively moved into and out of contact with the adjacent
wall of a borehole or pipe string as the tool is being operated. U.S. Pat.
No. 3,338,317 shows a perforating gun with a wall-engaging member that is
selectively extended and then retracted. Various arrangements have also
been utilized heretofore for selectively effecting the repetitive
movements of such wall-engaging members, with most tools of this nature
using a motor-powered hydraulic or mechanical tool-actuating system. By
way of example, U.S. Pat. No. 3,685,158 illustrates a typical
motor-powered hydraulic actuating system for selectively moving opposed
pad-supported electrical-measuring devices into and out of sliding
engagement with a borehole wall; and U.S. Pat. No. 3,686,943 shows tools
with a motor-driven mechanical actuating system for operating one or more
wall-engaging anchors. Likewise, U.S. Pat. No. 2,399,766 is involved with
an electrically-powered wireline setting tool to be used in setting
retrievable bridge plugs. U.S. Pat. No. 3,167,707 similarly discloses a
multi-arm dipmeter and calipering tool that is provided with a
motor-driven mechanism used for moving the arms back and forth between
their respective operating positions.
In addition to the usual service applications for tools with wall-engaging
members such as described in the aforementioned patents, the increasing
number of offshore wells throughout the world has called for a
reassessment of the applicability of many typical wireline tools for
service in such wells. Since many offshore wells are drilled in clusters
from a central location, such wells often include nearly-horizontal
intervals of considerable length respectively extended outwardly in
different directions from the drilling platform. Particular emphasis must
be given, therefore, toward facilitating the descent of all types of
wireline well tools into such deviated wells. For instance, for logging
operations in moderately-inclined wells, those tools requiring accurate
centralization are usually effectively supported by bow-spring
centralizers and calipers such as shown in U.S. Pat. No. 3,555,689.
As may be expected, however, it is quite difficult to move a
spring-centralized logging tool downwardly in well bores having
nearly-horizontal intervals since the substantial spring forces needed to
maintain the tool properly centered in such flat intervals correspondingly
increases the frictional drag of the bow-spring centralizers along the
borehole wall. The substantial spring forces needed to achieve suitable
centralization of a tool in such well bore intervals will, of course,
proportionally increase the amount of weight required to pull a given tool
downhole. Although it has been suggested that these bow-spring
centralizers might be temporarily held in a retracted position against the
tool body, experience has shown this is ordinarily impractical since these
tools must frequently be returned to lower depth locations in the
borehole. Thus, even if a stout centralizer was temporarily retracted,
once the bow springs were released it might well be impossible to later
move that tool back down a nearly-horizontal borehole interval.
It will be recognized, therefore, that many types of wireline tools require
tool-actuating systems which can be controlled from the surface for
selectively extending and retracting arms, bow springs, pads, rollers or
other types of wall-engaging members for well tools. Hydraulic actuating
systems such as shown in the aforementioned U.S. Pat. No. 3,685,158 are,
of course, suitable: but the physical size and quite-significant power
requirements of such systems will be excessive in many cases. Moreover,
the efficiency of such hydraulic tool-actuating systems is ordinarily
significantly less than what would ordinarily be expected with equivalent
electrically-driven systems such as the one shown in U.S. Pat. No.
3,686,943. On the other hand, despite their superior operating efficiency,
electrical tool-actuating systems such as shown in the last-mentioned
patent are generally considered to be too slow for safely operating in
those situations where a tool is subject to being easily stuck in the
borehole. Those skilled in the art will understand, of course, that the
slowness of such systems is not corrected by simply speeding the motor
since the attendant increase in power requirements usually makes it
impratical or impossible to employ such systems with small-diameter tools.
Accordingly, it is an object of the present invention to provide new and
improved well-bore apparatus that is to be repetitively operated and has
at least one wall-engaging member that is selectively moved to one of its
operating positions at a lower speed than when the wall-engaging member is
then moved from that position to another operating position.
This and other objects of the present invention are attained by placing a
movable tool-positioning member on a tool body and coupling the
tool-positioning member to selectively-rotatable driving means
cooperatively arranged so that, upon rotation in one rotational direction
the tool-positioning member is uncoupled from the driving means and is
then free for movement back and forth between an extended position and a
retracted position. Upon rotation in the other rotational direction, the
tool-positioning member is recoupled to the driving means and returned to
its retracted position.
The novel features of the present invention are set forth with
particularity in the appended claims. The invention, together with further
objects and advantages thereof, may be best understood by way of the
following description of exemplary apparatus employing the principles of
the invention as illustrated in the accompanying drawings in which:
FIG. 1 schematically depicts a new and improved well tool including a
motor-driven tool-actuating system arranged in accordance with the present
invention;
FIGS. 2 and 4 are enlarged cross-sectional views of a preferred embodiment
of a control mechanism to be used in the practice of the present
invention, with these drawings respectively illustrating alternative
positions of the control mechanism during its operation;
FIGS. 3-6 are transverse cross-sectional views of different portions of the
new and improved control mechanism as shown in FIGS. 2 and 4;
FIGS. 7A-7C are successive longitudinal cross-sectional views showing a
preferred embodiment of an arm-coupling assembly which can be incorporated
with a well tool utilizing the principles of the present invention;
FIGS. 8A-8C are successive longitudinal views which are similar to FIGS.
7A-7C but with each turned at right angles thereto so as to depict further
details of the arm-coupling assembly;
FIGS. 9-14 are transverse cross-sectional views respectively taken along
the corresponding section lines as indicated in FIGS. 7A, 7B and 8C; and
FIG. 15 is an isometric view of one portion of the arm-coupling assembly.
Turning to FIG. 1, a well tool 10 arranged as may be required for obtaining
one or more measurements or performing different services in a well bore
such as a cased interval or an open borehole, as at 11, is shown somewhat
schematically for purposes of simplifying the forthcoming description of a
new and improved tool-actuating system 12 incorporating the principles of
the present invention. In its preferred embodiment, the new and improved
actuating system 12 includes driving means 13 such as a
selectively-reversible, reduced-speed electric motor that is combined with
a typical gear-reduction unit and mounted in an enclosed chamber 14 in the
upper portion of the body 15 of the tool. The driving means 13 further
includes a rotatable output or driving shaft 16 operatively coupled to
coupling means as provided by a unique inline control mechanism 17 that is
preferably mounted in an oil-filled chamber 18 in the intermediate portion
of the tool body 15. As is customary, a typical pressure-balancing bellows
or piston (not shown) is arranged at some convenient location on the tool
body 15 and adapted as required for maintaining the oil-filled chamber 18
at an elevated pressure commensurate with the hydrostatic pressure of the
fluids in the borehole 11 as well as for accommodating thermal expansion
of the oil.
In the illustrated embodiment of the coupling means for the new and
improved tool-actuating system 12, the output shaft 19 of the control
mechanism 17 is coupled, as at 20, to force-and-motion converting means
such as a typical ball-bearing screw assembly 21 that is cooperatively
arranged for efficiently converting the rotational motions of the output
shaft into corresponding rectilinear or reciprocating movements of the
body 22 of the screw assembly as well as for converting the longitudinal
movements of the screw-assembly body into corresponding rotational motions
of the output shaft. The rectilinearly-movable nut or body 22 of the
motion-converting assembly 21 is slidably mounted within the intermediate
chamber 18 and co-rotatively secured against rotation in relation to the
tool body 15 by longitudinally-movable stop means such as a typical
longitudinal spline or key (not shown). In the preferred embodiment of the
tool-actuating system 12, the screw-assembly body 22 is coupled to a
tension-transmitting member such as a tubular shaft 23 having opposed
elongated slots, as at 24, on its opposite sides.
It will be appreciated, therefore, that upon selective rotation of the
output shaft 19 in, for example, a clockwise direction (as shown in FIG. 1
by the arrow 25), the body 22 and the depending tension-transmitting shaft
member 23 will be raised. Alternatively, selective rotation of the output
shaft 19 in the opposite rotational direction (i.e., a counterclockwise
rotation in this particular example) will be effective for moving the body
22 of the screw assembly 21 as well as the depending tension-transmitting
member 23 downwardly. It should also be understood that
downwardly-directed forces acting on the screw-assembly body 22 will be
effective for imposing a counterclockwise torque on the output shaft 19.
As depicted in FIG. 1, the new and improved tool-actuating system 12 is
shown as it is preferably arranged for selectively extending and
retracting tool-positioning means including one or more wall-engaging
members such as a first pair of elongated rigid arms, as at 26, which are
each pivotally connected, as at 27, to opposite sides of the body 15 and
cooperatively positioned in relation thereto so as to facilitate their
simultaneous operation in a vertical plane of movement that preferably
includes the central axis of the tool body. It will, of course, be
understood that with the tool 10 being a centralized tool, an
independently-movable second pair of arms (not illustrated) is similarly
arranged on the tool body 15 and preferably positioned for simultaneous
movement in a second vertical plane which substantially perpendicularly
intersects the plane of movement for the first pair of arms 26 so as to
maintain the tool in a centralized position in well bores such as the
borehole 11. Inasmuch as the particular mechanical arrangement used to
achieve independent operation of each pair of arms is, for the large part,
only incidental to understanding the new and improved tool-actuating
system 12 of the present invention, FIG. 1 is presented to show only the
first pair of arms 26.
As is typical, well tools such as the tool 10 may also include other types
of tool-positioning means with wall-engaging members such as electrode
pads or rollers 28 respectively connected to the tool body 15 by pivots as
at 29 on the outer end of each of the arms 26. Arm-biasing means, such as
an asse | | |
