Note: Descriptions are shown in the official language in which they were submitted.
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BORE MEASURING TOOL
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to measuring down-hole bores and in
particular to an apparatus and method for measuring well bores in line with a
tool string.
2. Description of Related Art
In oilfield applications, tubular wells (boreholes or wellbores) are
directionally
drilled through the earth using a drilling string suspended from a drilling
rig. A
drilling string is a collection of assembled parts including drill pipe, drill
collars,
tools and the drill bit. The parts are threadably coupled together to form the
drill string, with the drill bit on the distal end of the string. The drilling
rig may
include equipment to rotate the drilling string, or the drilling string may
include
a mud motor, which uses hydraulic energy from drilling fluid to turn the drill
bit,
independent of the drill string. The drilling fluid, also known as drilling
mud,
passes through the interior of the drilling string, exiting the string at the
drill bit
and is subsequently pumped back to the surface around the exterior of the
drilling string, carrying the drill cuttings with it for treatment and
disposal.
It is desirable and common practice to measure the physical properties of the
wellbore during or following drilling operations. Information may be obtained
about the well path and position, depth, bottom-hole location, geophysical
properties of the rock, etc. This information can be used to optimize the
efficiency of the wellbore placement and provide information for future well
use as well as any remedial steps which must be performed on the well bore.
Measurement while drilling (MWD) components may include a variety of
sensors which allow for continued drilling operation while collecting data
with
the sensors. It should be noted that in the art it is known to distinguish
between the terms "measurement while drilling" (MWD) and "logging while
drilling" (LWD) in that the MWD term generally refers to measurements
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relating to the progress of the drilling operation (such as the trajectory,
rate of
penetration, etc.), whereas LWD relates to information about the wellbore
physical properties (such as the porosity of the rock, vertical seismic
profile,
etc.). For the purpose of the description of the present invention, ¶wellbore
measurement" is intended to cover both classifications of sensors, without
limiting the type of sensors that may be described below.
Conventional methods of wellbore measurement have included tools with
multiple sensors. However, many of these tools are separate from the drill
string, not permitting a fluid bypass, and thus drilling operation must be
ceased and the drill string may need to be removed before such tools can be
inserted for measurements to be taken. Examples of such devices with
multiple sensors include CN102337884 CN202194563 and CN20241128, US
Patent Nos. 7,698,937 to Neidhardt, 4,673.890 to Copeland et al., 7,281,578 to
Nakajima et al. And US Patent Application Publication No. 2014/0138084 to Al-
Mu!hem.
Applicant is aware of wall contact caliper instruments for use in a drilling
string
which includes a bypass passage through the tool such that the drilling
operation does not need to be ceased while measurements are taken. Such
devices do not detect the profile of the well bore directly, but rather detect
the
difference in the height between the top and bottom of the tool to measure the
average diameter of the bore. Examples of such devices may be found in US
Patent No. 8,024,868 to Brannigan et al.
SUMMARY OF THE INVENTION
According to a first embodiment of the present invention there is disclosed an
apparatus for measuring a well bore wall comprising a casing connectable in
line with a tool string having a central passage therethrough and extending
between first and second ends and a plurality of longitudinally extending
biasing elements extending longitudinally along the body between first and
second ends wherein each of the second end of the biasing elements is
connected to the casing body. The apparatus further comprises a sensor
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located along a midpoint of each of the biasing elements and an engagement
body located within the central passage of the casing longitudinally
displaceable therein between first and second positions, wherein the
engagement body is connected to the first end of each of the biasing
elements such that displacement of the engagement body within the central
passage from the first to the second positions compresses and radially
extends the biasing elements so as to engage the sensors against the well
bore wall.
The central passage may have a first portion proximate to a first end of the
casing and a second portion at a middle thereof. The second portion of the
central passage may be larger than the first portion. The first and second
portions of the central passage may include an annular shelf extending
therebetween.
The engagement body may comprise a disk. The disk may have a diameter
larger than the first portion so as to be retained within the second portion.
The disk may include a plurality bores therethrough. The plurality of bores
may be positioned to be sealed by the disk when the disk is engaged thereon.
The casing may include a plurality of longitudinal slots extending therealong.
The apparatus may further include a carriage located in each slot. Each of
the carriages may be connected to the engagement body. The biasing
elements may extend along the slot. The biasing elements may extend
between the carriage and a distal end of the slot. The biasing elements may
comprise springs.
The apparatus may further comprise a transfer body positioned within the first
portion of the central passage being displaceable therein. The transfer body
may have leading edge adapted to receive a dropped ball thereon. The
transfer body may have a length selected to be located within the second
portion of the central passage at the second position of the engagement body.
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According to a further embodiment of the present invention there is disclosed
a
method for measuring a well bore wall comprising providing a casing in line
within a tool string and displacing an engagement body within a central
passage of the casing from a first position to a second position to compress
and radially extend a plurality of longitudinally extending biasing elements
connected thereto. The method further comprises recording at least one
measurement of the well bore wall with a sensor located on each of the
radially extended biasing elements.
Displacing the engagement body may comprises engaging a blocking body
upon a transfer sleeve above the engagement body, applying a pressure to a
top side of the blocking body and the transfer body and displacing and the
engagement body under the pressure. The method may further comprise
uncovering at least one bypass port through the engagement body at the
second position.
Other aspects and features of the present invention will become apparent to
those ordinarily skilled in the art upon review of the following description
of
specific embodiments of the invention in conjunction with the accompanying
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings which illustrate embodiments of the invention wherein similar
characters of reference denote corresponding parts in each view,
Figure 1 is a cross sectional view of a wellbore having a drilling string
therein which includes an apparatus for measuring the well bore
wall.
Figure 2 is a perspective view of a well bore measuring apparatus for
use
in the drilling string of Figure 1.
Figure 3 is a cross-sectional view of the apparatus of Figure 2 taken along
line 3-3 in a first or disengaged position.
Figure 4 is a cross-sectional view of the apparatus of Figure 2 taken
along
the line 3-3 in a second or extended position.
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Figure 5 is a cross sectional view of the apparatus of Figure 2 as
taken
along the line 5-5 of Figure 4.
Figure 6 is a detailed cross sectional view of one of the slots of
the
apparatus of Figure 2 as taken along the line 5-5 of Figure 4.
DETAILED DESCRIPTION
Referring to Figure 1, a wellbore 10 is drilled into the ground 8 by known
methods. The production zone may contain a horizontally extending
hydrocarbon bearing rock formation or may span a plurality of hydrocarbon
bearing rock formations such that the wellbore 10 has a path designed to
cross or intersect each formation. As illustrated in Figure 1, the wellbore
includes a drilling rig 12 at a top end thereof and a drilling or bottom hole
assembly 14 at a distal end of a drill string 16 extending therebetween. As
illustrated in Figure 1, a wellbore measuring apparatus 20 is located within
the
drill string 16 for measuring the properties and characteristics of the well
bore
wall 18 as will be further described below.
Turning to Figures 2 through 4, an apparatus 20 for measuring a well bore as
set out above comprises a casing 22 extending between first and second
ends, 24 and 26, respectively and including a middle or cage portion 28 at a
middle thereof. As illustrated in Figures 3 and 4, the apparatus 20 includes a
plurality of spring biased sensors 30 extendable by the displacement of an
actuating plate 40 therein into contact with, or proximity to the well bore
wall
18 as will be described further below.
The casing 22 is sized to be coupled within the drill string 16, and having
internal end threading 32 at the first end 24 and external end threading 34 at
the second end 26. The internal and external threading, 32, 34, are selected
to correspond to and be nnatable with other drill string threading, as are
commonly known. The casing 22 defines an interior passage 36 therethrough
having a lead portion 42 proximate to the first end 24 and a cage portion 28
located at the midpoint thereof. The diameter of the lead portion 42 of the
interior passage 36 is less than the diameter of the cage portion 28. An
inward
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annular shoulder 44 defines the separation between the lead portion 42 and
cage portion 28. A bottom portion 46 of the interior passage 36 I located
proximate to the second end 26 end and matches the diameter of the lead
portion 42, with an annular shoulder 48 between the cage and bottom portions
28, 46.
As shown best on Figure 5, the cage portion 28 of the casing 22 includes a
plurality of longitudinal slots 50 extending through the casing 22 which may
be
distributed axially around the casing 22 at the cage portion 28. The quantity
of
slots 50 may range from 10 to 18, although it may be appreciated that other
quantities May be useful, as well. As illustrated, the slots 50 may be
arranged
radially at regular angles around the casing although it will be appreciated
that
other configurations may be useful as well. The slots 50 extend between a
first end 52 located towards the first end 24 of the casing 22 and slot second
end 54 located towards the second end 26 of the casing 22. A carriage 56 is
located within each slot. A leaf spring 58, or other biasing member, may be
fixed to the carriage 56 and to the casing 22 at the second end 54 of the slot
50. Each slot 50 is sealed with an anticorrosive rubber seal 60 located
therein
which incorporates a slit 62 through which each carriage 56 may be
connected to the actuating plate 40 as illustrated in Figure 6. The carriages
56 may include a narrowed portion 57 extending through the slit 62 to the
actuating plate 40. Sensors 30 may be attached to each leaf spring 58 and
may be extended therefrom. As illustrated, the sensors 30 may be located at
a midpoint of the leaf spring 58 span, although other locations may be useful
as well. As illustrated in Figure 3, the leaf spring 58 may be sized to
substantially span the length of the slot 50 when in the resting or inert
position
so as to position the carriage proximate to the first end 52 of the slot 50 at
such position.
Referring to Figures 3, 4 and 5, the cage portion 28 contains a disk shaped
actuating plate 40 sized to fit therein. The diameter of the actuating plate
40 is
sized to slide within the cage portion 28, having a larger diameter than the
lead portion 42 of the interior passage, such that the actuating plate 40 will
not
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slide past annular shoulder 44. The actuating plate 40 may have a thickness
ranging such as from 1 to 2 inches (25.4 to 50.8 mm), although it may be
appreciated that other thicknesses may be useful, as well. A plurality of
bypass bores 60 are positioned in a circular array proximate to the exterior
edge of the actuating plate 40, such that they are positioned to be covered by
the annular shoulder 44 when the actuating plate 40 is located at the first
position as illustrated in Figure 3. A central bore 41 is located in the
centre of
the actuating plate 40 to permit fluid to pass therethrough prior to a ball
being
dropped into contact with the ball seat as set out below. The plurality of
carriages 56 may be attached to the actuating plate 40 such that they are
seated within the plurality of slots 50.
A cylindrical engagement sleeve 70 is sized to fit within the lead portion 42
such that it can slide therein. The engagement sleeve 70 extends between
lead and second ends 72 and 74, respectively, with a central bore 76 defining
a passage 78 therethrough. The passage 78 continues through central bore
41 in the actuating plate 40. The central bore 76 has a profiled ball seat 79
at
the lead end 72 such that an engagement ball 80 can be seated therein, thus
sealing passage 78, as shown in Figure 4. The length of engagement sleeve
70 may range such as from 6 to 24 inches (152 to 610 mm), although it may
be appreciated that other lengths may be useful, as well. The engagement
sleeve 70 is maintained in position by spring loaded wedges 84 located below
the ball seat 70. After the ball seat 70 is shifted downwardly within the
interior
passage 36, the wedges 84 will return to their extended position as
illustrated
thereby preventing an upward return of the ball seat 70 to the run in
position.
It will also be appreciated that other devices for retaining the ball seat 70
at
the run in position illustrated in Figure 3 may also be utilized such as, by
way
of non-limiting example, shear pins or the like.
In operation the apparatus 20 may be located within a drill string 16 and the
drilling operation performed as is commonly known. When an operator desires
to activate the apparatus 20, an engagement ball 80 is released within the
drill
string 16. The ball 80 is sized to pass through the interior passage of all
drill
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string 16 components, and to be seated snugly within the ball seat 79 of the
engagement sleeve 70. As the ball 80 is seated within engagement sleeve 70,
the hydraulic fluid builds pressure on the now sealed engagement sleeve 70,
which shifts down past the pressure gradient mechanisms to engage upon the
actuating plate 40. Further pressure thereon displaces the actuating plate 40
and engagement sleeve 70 within cage portion 28, longitudinally sliding the
carriages 56 within the slots 50 and subsequently extending leaf springs 58
with attached sensors 30 through the slits in the rubber seals. As the
actuating plate 40 is displaced within the cage portion 28, bypass bores 60
are exposed, allowing hydraulic fluid to pass therethrough once the
engagement sleeve 70 has been displaced past annular shoulder 44, as
indicated at 100 on Figure 4, while maintaining sufficient pressure to
continuously maintain the sensors at the extended position. Hydraulic fluid
continues to pass through passages 36 and 82, allowing continued operation
of the drill string during wellbore measurement with the sensors 30.
Sensors 30 may be radius proximity sensors, or other sensor types commonly
used in the art, depending on the desired data outcome. As there are a
plurality of sensors on the cage portion 28, a variety of sensor types could
be
mounted on leaf springs 58. The sensors 30 may be connected, as is
commonly known, by wire to a memory card 90 enclosed within the casing 22.
It will be appreciated that the sensors 30 may be selected to measure a
desired characteristic of the well bore as are commonly known in the art. The
memory card 90 could store data received from the sensors 30 until the
apparatus 20 is removed from the wellbore 10 for review following the drilling
operation. Alternately, signals from the sensors 30 may be communicated to
the surface over a signal line, within wired drill pipe, or through any other
method as is commonly known in the art.
The casing 22 may be fabricated using metal composites, using any common
forming methods, such as casting, molding, or machining, by way of non-
limiting example. It will be appreciated that all components of the present
device will be required to be formed of materials and in sufficient
thicknesses
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and dimensions to withstand the torque stress, pressure, temperature and
anticorrosive standards of bottom hole assemblies as are commonly known.
While specific embodiments of the invention have been described and
illustrated, such embodiments should be considered illustrative of the
invention only and not as limiting the invention as construed in accordance
with the accompanying claims.
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