U.S. patent application number 12/253778 was filed with the patent office on 2010-04-22 for reamer roller cone bit with stepped reamer cutter profile.
This patent application is currently assigned to BAKER HUGHES INCORPORATED. Invention is credited to Robert J. Buske.
Application Number | 20100096188 12/253778 |
Document ID | / |
Family ID | 42107740 |
Filed Date | 2010-04-22 |
United States Patent
Application |
20100096188 |
Kind Code |
A1 |
Buske; Robert J. |
April 22, 2010 |
REAMER ROLLER CONE BIT WITH STEPPED REAMER CUTTER PROFILE
Abstract
A bottom hole assembly including a pilot bit for initially
forming an unconfined inner sidewall of a wellbore and a reamer
tool above the pilot bit and comprising a first cutter ring to
expand the unconfined inner sidewall, and a second cutter ring
located above and outwardly of the first cutter ring to expand the
unconfined inner sidewall as expanded by the first cutter ring. The
reamer tool may further comprise a third cutter ring located above
and outwardly of the second cutter ring to expand the unconfined
inner sidewall as expanded by the second cutter ring. The first
cutter ring may be located on a first roller cone, the second
cutter ring may be located on a second roller cone, and the third
cutter ring may be located on a third roller cone.
Inventors: |
Buske; Robert J.; (The
Woodlands, TX) |
Correspondence
Address: |
LOCKE LORD BISSELL & LIDDELL LLP;ATTN: IP DOCKETING
600 TRAVIS, SUITE 3400
HOUSTON
TX
77002-3095
US
|
Assignee: |
BAKER HUGHES INCORPORATED
Houston
TX
|
Family ID: |
42107740 |
Appl. No.: |
12/253778 |
Filed: |
October 17, 2008 |
Current U.S.
Class: |
175/57 ;
175/391 |
Current CPC
Class: |
E21B 10/28 20130101 |
Class at
Publication: |
175/57 ;
175/391 |
International
Class: |
E21B 10/40 20060101
E21B010/40 |
Claims
1. A reamer tool for expanding a wellbore in an earth formation,
the reamer tool comprising: a first roller cone having a first
cutter ring configured to expand an unconfined inner sidewall of
the wellbore; and a second roller cone having a second cutter ring
located above and outwardly of the first cutter ring and configured
to expand the unconfined inner sidewall of the wellbore as expanded
by the first cutter ring.
2. The reamer tool as set forth in claim 1, further comprising a
third roller cone having a third cutter ring located above and
outwardly of the second cutter ring and configured to expand the
unconfined inner sidewall as expanded by the second cutter
ring.
3. The reamer tool as set forth in claim 2, further comprising a
fourth cutter ring located on the first roller cone above and
outwardly of the third cutter ring and configured to expand the
unconfined inner sidewall as expanded by the third cutter ring.
4. The reamer tool as set forth in claim 3, further comprising a
fifth cutter ring located on the second roller cone above and
outwardly of the fourth cutter ring and configured to expand the
unconfined inner sidewall as expanded by the fourth cutter
ring.
5. The reamer tool as set forth in claim 4, further comprising a
sixth cutter ring located on the third roller cone above and
outwardly of the fifth cutter ring and configured to expand the
unconfined inner sidewall as expanded by the fifth cutter ring.
6. A bottom hole assembly comprising: a pilot bit for initially
forming an unconfined inner sidewall of a wellbore; and a reamer
tool above the pilot bit, the reamer tool including a first cutter
ring configured to expand the unconfined inner sidewall of the
wellbore, a second cutter ring located above and outwardly of the
first cutter ring and configured to expand the unconfined inner
sidewall as expanded by the first cutter ring, and a third cutter
ring located above and outwardly of the second cutter ring and
configured to expand the unconfined inner sidewall as expanded by
the second cutter ring.
7. The bottom hole assembly as set forth in claim 6, the reamer
tool further comprising first, second and third roller cones.
8. The bottom hole assembly as set forth in claim 7, wherein the
first cutter ring is located on the first roller cone, the second
cutter ring located on the second roller cone, and the third cutter
ring is located on the third roller cone.
9. The bottom hole assembly as set forth in claim 8, further
comprising a fourth cutter ring located on the first roller cone
above and outwardly of the third cutter ring and configured to
expand the unconfined inner sidewall as expanded by the third
cutter ring; a fifth cutter ring located on the second roller cone
above and outwardly of the fourth cutter ring and configured to
expand the unconfined inner sidewall as expanded by the fourth
cutter ring; and a sixth cutter ring located on the third roller
cone above and outwardly of the fourth cutter ring and configured
to expand the unconfined inner sidewall as expanded by the fifth
cutter ring.
10. The bottom hole assembly as set forth in claim 9, wherein each
roller cone includes at least three cutter rows, wherein successive
cutter rows are located above and outwardly of previous cutter rows
such that each cutter row engages the wellbore in such a manner as
to incrementally expand the wellbore outwardly.
11. The bottom hole assembly as set forth in claim 9, wherein the
wellbore is defined by an unconfined inner sidewall and successive
cutter rows are located above and outwardly of previous cutter rows
such that each cutter row engages the wellbore in such a manner as
to incrementally expand the unconfined inner sidewall
outwardly.
12. A method of expanding a wellbore using a reamer tool comprising
a plurality of cutter rows mounted on a plurality of roller cones,
the method comprising the steps of: engaging, with a first cutter
row on a first roller cone, an unconfined inner sidewall of the
wellbore, thereby expanding the wellbore outwardly; and engaging,
with a second cutter row located on a second roller cone above and
outwardly of the first cutter row, the unconfined inner sidewall of
the wellbore as expanded by the first cutter row, thereby further
expanding the wellbore outwardly.
13. The method as set forth in claim 12, further including the step
of engaging, with a third cutter row located on a third roller cone
above and outwardly of the second cutter row, the unconfined inner
sidewall of the wellbore as expanded by the second cutter row,
thereby further expanding the wellbore outwardly.
14. The method as set forth in claim 13, further including the
steps of engaging, with a fourth cutter row located on the first
roller cone above and outwardly of the third cutter row, the
unconfined inner sidewall of the wellbore as expanded by the third
cutter row; engaging, with a fifth cutter row located on the second
roller cone above and outwardly of the fourth cutter row, the
unconfined inner sidewall of the wellbore as expanded by the fourth
cutter row; and engaging, with a sixth cutter row located on the
third roller cone above and outwardly of the fifth cutter row, the
unconfined inner sidewall of the wellbore as expanded by the fifth
cutter row.
15. The method as set forth in claim 12, wherein the reamer expands
the wellbore outwardly from the unconfined inner sidewall of the
wellbore and the reamer tool is lowered in the wellbore.
16. The method as set forth in claim 12, wherein the wellbore is
defined by an initial inner sidewall formed by a pilot bit below
the reamer tool, a first step formed by the first cutter row
adjacent the initial inner sidewall, a second step formed by the
second cutter row above and outward of the first step, and a final
inner sidewall formed by the reamer tool.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The inventions disclosed and taught herein relate generally
to drilling assemblies for drilling wellbores into earth
formations; and more specifically related to reamer tools for such
drilling assemblies.
[0006] 2. Description of the Related Art
[0007] U.S. Pat. No. 4,106,577 discloses a "hydromechanical
drilling tool which combines a high pressure water jet drill with a
conventional roller cone type of drilling bit. The high pressure
jet serves as a tap drill for cutting a relatively small diameter
hole in advance of the conventional bit. Auxiliary laterally
projecting jets also serve to partially cut rock and to remove
debris from in front of the bit teeth thereby reducing
significantly the thrust loading for driving the bit."
[0008] U.S. Pat. No. 4,141,421 discloses "an under reamer tool for
enlarging, scraping or smoothing a well bore. The tool is attached
to a conventional drill string above a conventional bit and
involves cutting elements that have retractable cutters arranged
for extension from the tool to engage the well bore wall, each
cutter, when the drill string is turned, being urged outwardly by
centrifugal force until it engages the well bore wall, continued
turning thereafter, pulling that cutter into its extended cutting
attitude, reaming the wall to the desired diameter, cutter
retraction involving ceasing turning the drill string and the
pulling of the drill string and connected tool from the well bore.
During that pulling should the cutter contact a shoe or first
reduction of the well bore casing or the wall thereof, it will be
urged into a stowed attitude recessed within the tool body, the
under reamer tool of the present invention also incorporating
scouring openings provided in the tool body opposite to the cutter
storage areas to pass liquid or air therethrough from the drill
string to purge and clean that area within the tool body, allowing
the cutter to travel freely therein."
[0009] U.S. Pat. No. 5,497,842 discloses a "reaming apparatus for
enlarging a borehole, including a tubular body having one or more
longitudinally and generally radially extending blades
circumferentially spaced thereabout. Each of the blades carries
highly exposed cutting elements, on the order of fifty percent
exposure, on its profile substantially all the way to the gage. At
least one of the blades is a primary blade for cutting the full or
drill diameter of the borehole, while one or more others of the
blades may be secondary blades which extend a lesser radial
distance from the body than the primary blade. A secondary blade
initially shares a large portion of the cutting load with the
primary blade while the borehole size is in transition between a
smaller, pass through diameter and drill diameter. It functions to
enhance the rapidity of the transition while balancing side
reaction forces, and reduces vibration and borehole eccentricity.
After drill diameter is reached, cutting elements on the secondary
blade continue to share the cutting load over the radial distance
they extend from the body."
[0010] U.S. Pat. No. 6,439,326 discloses a "drill bit including a
roller cone and fixed cutters positioned external to the roller
cone and radially from the bit axis of rotation. The roller cone is
located so that a drill diameter of the cone is substantially
concentric with an axis of rotation of the bit. The fixed cutters
can be made of tungsten carbide, polycrystalline diamond, boron
nitride, or any other superhard material. The fixed cutters are
positioned to either maintain the hole diameter drilled by the
roller cone or to drill a larger diameter hole than the hole
drilled by the roller cone. The single roller cone may be located
in the center of a multi-cone bit arrangement or in the center of a
PDC bit to assist in drilling the center of a wellbore. The single
roller cone may be used to form a bi-center bit in combination with
a reaming section. The single roller cone may also be located on an
independent sub that is removably attached to the bit body."
[0011] U.S. Pat. No. 6,729,418 discloses a "back reaming tool is
disclosed which includes a tool body adapted to be coupled to a
drill string, and at least one roller cone rotatably mounted to a
leg and having cutting elements disposed thereon. The leg is
removably coupled to the tool body. The at least one roller cone is
open at only one axial end thereof."
[0012] U.S. Pat. No. 7,090,034 discloses "a reamer (100) having at
least one journal body (110) and at least one toroidal cutter body
(116). The toroidal cutter body (116) has a maximum diameter (MD),
an outer perimeter (OP) and a plurality of cutting elements (112,
145, 149) on the cutting surface (118). The toroidal cutter body is
rotatably attached to the journal (110). When in the installed
position, the axis of rotation (RA) of the at least one toroidal
cutter body (116) intersects the longitudinal axis of the drill
string at an acute angle."
[0013] The inventions disclosed and taught herein are directed to
an improved system for drilling and expanding wellbores into earth
formations.
BRIEF SUMMARY OF THE INVENTION
[0014] In one embodiment, the present invention comprises a bottom
hole assembly including a pilot bit for initially forming an
unconfined inner sidewall of a wellbore and a reamer tool above the
pilot bit, the reamer tool comprising a first cutter ring
configured to expand the unconfined inner sidewall of the wellbore,
and a second cutter ring located above and outwardly of the first
cutter ring and configured to expand the unconfined inner sidewall
as expanded by the first cutter ring. The reamer tool may further
comprise a third cutter ring located above and outwardly of the
second cutter ring and configured to expand the unconfined inner
sidewall as expanded by the second cutter ring. The first cutter
ring may be located on a first roller cone, the second cutter ring
may be located on a second roller cone, and the third cutter ring
may be located on a third roller cone. The reamer tool may further
comprise a fourth cutter ring located on the first roller cone
above and outwardly of the third cutter ring and configured to
expand the unconfined inner sidewall as expanded by the third
cutter ring, a fifth cutter ring located on the second roller cone
above and outwardly of the fourth cutter ring and configured to
expand the unconfined inner sidewall as expanded by the fourth
cutter ring, and a sixth cutter ring located on the third roller
cone above and outwardly of the fourth cutter ring and configured
to expand the unconfined inner sidewall as expanded by the fifth
cutter ring. Each roller cone may include three cutter rows,
wherein successive cutter rows are located above and outwardly of
previous cutter rows such that each cutter row engages the wellbore
in such a manner as to incrementally expand the wellbore outwardly.
In one embodiment, the wellbore is defined by an unconfined inner
sidewall and successive cutter rows are located above and outwardly
of previous cutter rows such that each cutter row engages the
wellbore in such a manner as to incrementally expand the unconfined
inner sidewall outwardly.
[0015] In another embodiment, the present invention includes a
reamer tool for expanding a wellbore in an earth formation, the
reamer comprising a first roller cone having a first cutter ring
configured to expand an unconfined inner sidewall of the wellbore
and a second roller cone having a second cutter ring located above
and outwardly of the first cutter ring and configured to expand the
unconfined inner sidewall of the wellbore as expanded by the first
cutter ring. The reamer tool may further comprise a third roller
cone having a third cutter ring located above and outwardly of the
second cutter ring and configured to expand the unconfined inner
sidewall as expanded by the second cutter ring. The reamer tool may
further comprise a fourth cutter ring located on the first roller
cone above and outwardly of the third cutter ring and configured to
expand the unconfined inner sidewall as expanded by the third
cutter ring. The reamer tool may further comprise a fifth cutter
ring located on the second roller cone above and outwardly of the
fourth cutter ring and configured to expand the unconfined inner
sidewall as expanded by the fourth cutter ring. The reamer tool may
further comprise a sixth cutter ring located on the third roller
cone above and outwardly of the fifth cutter ring and configured to
expand the unconfined inner sidewall as expanded by the fifth
cutter ring.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] FIG. 1 illustrates a simplified embodiment of a bottomhole
assembly utilizing certain aspects of the present inventions;
[0017] FIG. 2 illustrates a close-up view of a simplified
embodiment of a roller cone reamer tool in operation expanding a
wellbore, shown with multiple roller cones and cutters
overlain;
[0018] FIG. 3 illustrates a particular embodiment of a roller cone
utilizing certain aspects of the present inventions;
[0019] FIG. 4 illustrates another particular embodiment of a roller
cone utilizing certain aspects of the present inventions;
[0020] FIG. 5 illustrates another particular embodiment of a roller
cone utilizing certain aspects of the present inventions;
[0021] FIG. 6 illustrates another particular embodiment of a roller
cone utilizing certain aspects of the present inventions;
[0022] FIG. 7 illustrates a composite view of the roller cones of
FIGS. 3-6 overlain; and
[0023] FIG. 8 illustrates another close-up view of a simplified
embodiment of a roller cone reamer tool in operation expanding a
wellbore, shown with multiple roller cones and cutters
overlain.
DETAILED DESCRIPTION
[0024] The Figures described above and the written description of
specific structures and functions below are not presented to limit
the scope of what Applicants have invented or the scope of the
appended claims. Rather, the Figures and written description are
provided to teach any person skilled in the art to make and use the
inventions for which patent protection is sought. Those skilled in
the art will appreciate that not all features of a commercial
embodiment of the inventions are described or shown for the sake of
clarity and understanding. Persons of skill in this art will also
appreciate that the development of an actual commercial embodiment
incorporating aspects of the present inventions will require
numerous implementation-specific decisions to achieve the
developer's ultimate goal for the commercial embodiment. Such
implementation-specific decisions may include, and likely are not
limited to, compliance with system-related, business-related,
government-related and other constraints, which may vary by
specific implementation, location and from time to time. While a
developer's efforts might be complex and time-consuming in an
absolute sense, such efforts would be, nevertheless, a routine
undertaking for those of skill this art having benefit of this
disclosure. It must be understood that the inventions disclosed and
taught herein are susceptible to numerous and various modifications
and alternative forms. Lastly, the use of a singular term, such as,
but not limited to, "a," is not intended as limiting of the number
of items. Also, the use of relational terms, such as, but not
limited to, "top," "bottom," "left," "right," "upper," "lower,"
"down," "up," "side," and the like are used in the written
description for clarity in specific reference to the Figures and
are not intended to limit the scope of the invention or the
appended claims.
[0025] Applicants have created a bottom hole assembly including a
pilot bit for initially forming an unconfined inner sidewall of a
wellbore and a reamer tool above the pilot bit and comprising a
first cutter ring to expand the unconfined inner sidewall and a
second cutter ring located above and outwardly of the first cutter
ring to expand the unconfined inner sidewall as expanded by the
first cutter ring. The reamer tool may further comprise a third
cutter ring located above and outwardly of the second cutter ring
to expand the unconfined inner sidewall as expanded by the second
cutter ring. The first cutter ring may be located on a first roller
cone, the second cutter ring may be located on a second roller
cone, and the third cutter ring may be located on a third roller
cone.
[0026] FIG. 1 is an illustration of a bottomhole assembly 10 in
which the reamer tool 100 of the present invention may be employed.
The bottomhole assembly may be similar to that shown and described
in U.S. Pat. No. 5,497,842, incorporated herein by specific
reference. The bottomhole assembly 10 may include one or more drill
collars 12 suspended from a distal end of a drill string extending
to the rig floor at the surface. An optional pass through
stabilizer 14 may be secured to the drill collar 12. The stabilizer
14 may be sized equal to or slightly smaller than the pass through
diameter of the bottomhole assembly 10, which may be defined as the
smallest diameter borehole through which the assembly may move
longitudinally. Another drill collar 16 (or other drill string
element such as an measurement while drilling (MWD) tool housing or
pony collar) may be secured to the bottom of the stabilizer 14,
below which the reamer tool 100 according to the present invention
is secured via a tool joint 18, which may be an American Petroleum
Institute (API) joint. More specifically, in one embodiment, a 75/8
inch API pin connector is located at the top of the reamer tool
100. Another API joint 22 is located at the bottom of the reamer
tool 100. More specifically, in one embodiment, a 65/8 inch API box
connector is located at the bottom of the reamer tool 100. An upper
pilot stabilizer 24, preferably secured to the reamer tool 100, is
of an O.D. equal to or slightly smaller than that of a pilot bit 30
at the bottom of the assembly 10. Yet another, smaller diameter
drill collar 26 may be secured to the lower end of the upper pilot
stabilizer 24, followed by a lower pilot stabilizer 28 to which is
secured the pilot bit 30. The pilot bit 30 may be either a rotary
drag bit or a tri-cone, so-called "rock bit". The bottomhole
assembly 10 as described is exemplary only, it being appreciated by
those of ordinary skill in the art that many other assemblies and
variations may be employed.
[0027] The bottomhole assembly 10 creates and expands a borehole,
or wellbore, in an earth formation. The borehole preferably
includes an initial inner sidewall 40 created by the pilot bit 30.
The borehole also preferably includes a final inner sidewall 42
created by the reamer tool 100, as will be discussed in greater
detail below. Between the initial inner sidewall 40 and the final
inner sidewall 42, there is a working surface 44 of the reamer tool
100. In one embodiment of the reamer tool 100, this working surface
44 is a generally conical surface sloped upwardly and outwardly
from the initial inner sidewall 40 to the final inner sidewall 42.
As can be seen in FIG. 2 and as will be discussed in greater detail
below, while the working surface 44 is generally linear, the
working surface 44 is actually discontinuous and comprised of a
series of steps, stepping up and outward from the initial inner
sidewall 40 to the final inner sidewall 42. Where the working
surface 44 meets the initial inner sidewall 40, the wellbore forms
an inner corner 46. It can be seen that the initial inner sidewall
40, the final inner sidewall 42, the working surface 44, and the
inner corner 46 are all unconstrained, or unconfined, toward the
interior of the wellbore. As will be discussed in greater detail
below, the reamer tool 100 of the present invention takes advantage
of this unconfined characteristic.
[0028] In one preferred embodiment, as shown in FIG. 3, FIG. 4,
FIG. 5, and FIG. 6, the reamer tool 100 includes four roller cones
102,104,106,108, each with a plurality of rings, or rows, of
cutters 110. In another preferred embodiment, the reamer tool 100
includes three roller cones 102,104,106, each with a plurality of
rings, rows, of cutters 110. In any case, the reamer tool 100 is
expected to have between two and eight roller cones. FIG. 7 shows
how, in actual use, the roller cones 102,104,106,108 effectively
overlap, such that the cutters 110 of the roller cones
102,140,106,108 form a cutting profile 112, which engages and
therefore effectively defines, or creates, the working surface 44
of the wellbore.
[0029] The roller cones 102,104,106,108 are angled such that the
cutters 110 successively engage the earth formation upwardly and
outwardly. It can be appreciated that the pilot bit 30 has
initiated the borehole, or wellbore, thereby creating the initial
unconfined inner sidewall 40 of the wellbore. An uppermost edge of
the initial unconfined inner sidewall forms the unconfined inner
corner 46a of the wellbore. Being unconfined, open to the initial
inner sidewall 40 formed by the pilot bit 30 below the reamer tool
100, this inner corner 46a is less resistant to excavation. This is
due to the fact that the inner corner 46a is only confined, or
constrained, outwardly. In other words, the inner corner 46a is
unconfined, or constrained inwardly, as the earth formation
inwardly has already been removed by the pilot bit 30.
[0030] Therefore, successive rows, or rings, of the cutters 110
preferably engage the unconfined portions of the wellbore,
successively expanding the wellbore outwardly. More specifically,
referring also to FIG. 8, a first row 114a of cutters 110 engages
the unconfined inner corner 46a of the wellbore, thereby expanding
the initial inner sidewall 40 of the wellbore outwardly. As the
bottomhole assembly 10 is lowered into the wellbore and the first
row 114a of cutters 110 engages and excavates this unconfined inner
corner 46a, the cutters 110 move the unconfined inner corner 46a
downwardly. The first row 114a of cutters 110 also creates a first
step 48a in the wellbore. This first step 48a begins at the
unconfined inner corner 46a of the wellbore and extends outwardly
therefrom. The first step 48a also extends upwardly slightly,
forming a second unconfined corner 46b of the wellbore.
[0031] Next, a second row 114b of cutters 110 engages the second
unconfined corner 46b of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
second row 114b of cutters 110 engages and excavates this second
unconfined corner 46b, the cutters 110 move the second unconfined
corner 46b downwardly. The second row 114b of cutters 110 also
creates a second step 48b in the wellbore. This second step 48b
begins at the second unconfined corner 46b of the wellbore and
extends outwardly therefrom. The second step 48b also extends
upwardly slightly, forming a third unconfined corner 46c of the
wellbore.
[0032] Next, a third row 114c of cutters 110 engages the third
unconfined corner 46c of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
third row 114c of cutters 110 engages and excavates this third
unconfined corner 46c, the cutters 110 move the third unconfined
corner 46c downwardly. The third row 114c of cutters 110 also
creates a third step 48c in the wellbore. This third step 48c
begins at the third unconfined corner 46c of the wellbore and
extends outwardly therefrom. The third step 48c also extends
upwardly slightly, forming a fourth unconfined corner 46d of the
wellbore.
[0033] Next, a fourth row 114d of cutters 110 engages the fourth
unconfined corner 46d of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
fourth row 114d of cutters 110 engages and excavates this fourth
unconfined corner 46d, the cutters 110 move the fourth unconfined
corner 46d downwardly. The fourth row 114d of cutters 110 also
creates a fourth step 48d in the wellbore. This fourth step 48d
begins at the fourth unconfined corner 46d of the wellbore and
extends outwardly therefrom. The fourth step 48d also extends
upwardly slightly, forming a fifth unconfined corner 46e of the
wellbore.
[0034] Next, a fifth row 114e of cutters 110 engages the fifth
unconfined corner 46e of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
fifth row 114e of cutters 110 engages and excavates this fifth
unconfined corner 46e, the cutters 110 move the fifth unconfined
corner 46e downwardly. The fifth row 114e of cutters 110 also
creates a fifth step 48e in the wellbore. This fifth step 48e
begins at the fifth unconfined corner 46e of the wellbore and
extends outwardly therefrom. The fifth step 48e also extends
upwardly slightly, forming a sixth unconfined corner 46f of the
wellbore.
[0035] Next, a sixth row 114f of cutters 110 engages the sixth
unconfined corner 46f of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
sixth row 114f of cutters 110 engages and excavates this sixth
unconfined corner 46f, the cutters 110 move the sixth unconfined
corner 46f downwardly. The sixth row 114f of cutters 110 also
creates a sixth step 48f in the wellbore. This sixth step 48f
begins at the sixth unconfined corner 46f of the wellbore and
extends outwardly therefrom. The sixth step 48f also extends
upwardly slightly, forming a seventh unconfined corner 46g of the
wellbore.
[0036] Next, a seventh row 114g of cutters 110 engages the seventh
unconfined corner 46g of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
seventh row 114g of cutters 110 engages and excavates this seventh
unconfined corner 46g, the cutters 110 move the seventh unconfined
corner 46g downwardly. The seventh row 114g of cutters 110 also
creates a seventh step 48g in the wellbore. This seventh step 48g
begins at the seventh unconfined corner 46g of the wellbore and
extends outwardly therefrom. The seventh step 48g also extends
upwardly slightly, forming an eighth unconfined corner 46h of the
wellbore.
[0037] Next, an eighth row 114h of cutters 110 engages the eighth
unconfined corner 46h of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
eighth row 114h of cutters 110 engages and excavates this eighth
unconfined corner 46h, the cutters 110 move the eighth unconfined
corner 46h downwardly. The eighth row 114h of cutters 110 also
creates an eighth step 48h in the wellbore. This eighth step 48h
begins at the eighth unconfined corner 46h of the wellbore and
extends outwardly therefrom. The eighth step 48h also extends
upwardly slightly, forming a ninth unconfined corner 46i of the
wellbore.
[0038] Next, a ninth row 114i of cutters 110 engages the ninth
unconfined corner 46i of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
ninth row 114i of cutters 110 engages and excavates this ninth
unconfined corner 46i, the cutters 110 move the ninth unconfined
corner 46i downwardly. The ninth row 114i of cutters 110 also
creates a ninth step 48i in the wellbore. This ninth step 48i
begins at the ninth unconfined corner 46i of the wellbore and
extends outwardly therefrom. The ninth step 48i also extends
upwardly slightly, forming a tenth unconfined corner 46j of the
wellbore.
[0039] Next, a tenth row 114j of cutters 110 engages the tenth
unconfined corner 46j of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
tenth row 114j of cutters 110 engages and excavates this tenth
unconfined corner 46j, the cutters 110 move the tenth unconfined
corner 46j downwardly. The tenth row 114j of cutters 110 also
creates a tenth step 48j in the wellbore. This tenth step 48j
begins at the tenth unconfined corner 46j of the wellbore and
extends outwardly therefrom. The tenth step 48j also extends
upwardly slightly, forming an eleventh unconfined corner 46k of the
wellbore.
[0040] Next, an eleventh row 114k of cutters 110 engages the
eleventh unconfined corner 46k of the wellbore, thereby
successively expanding the initial inner sidewall 40 of the
wellbore outwardly. As the bottomhole assembly 10 is lowered into
the wellbore and the eleventh row 114k of cutters 110 engages and
excavates this eleventh unconfined corner 46k, the cutters 110 move
the eleventh unconfined corner 46k downwardly. The eleventh row
114k of cutters 110 also creates an eleventh step 48k in the
wellbore. This eleventh step 48k begins at the eleventh unconfined
corner 46k of the wellbore and extends outwardly therefrom. The
eleventh step 48k also extends upwardly slightly, forming a twelfth
unconfined corner 46l of the wellbore.
[0041] Next, a twelfth row 114l of cutters 110 engages the twelfth
unconfined corner 46l of the wellbore, thereby successively
expanding the initial inner sidewall 40 of the wellbore outwardly.
As the bottomhole assembly 10 is lowered into the wellbore and the
twelfth row 114l of cutters 110 engages and excavates this twelfth
unconfined corner 46l, the cutters 110 move the twelfth unconfined
corner 46l downwardly. The twelfth row 114l of cutters 110 also
creates a twelfth step 48l in the wellbore. This twelfth step 48l
begins at the twelfth unconfined corner 46l of the wellbore and
extends outwardly therefrom. In one embodiment of the reamer tool
100, the twelfth step 48l terminates in the final inner sidewall 42
of the wellbore.
[0042] The rows 114a-114l of cutters 110 are preferably dispersed
across the roller cones 102-108. In the embodiment of the reamer
tool having four roller cones 102-108, each roller cones preferably
has three of the rows 114a-114l of cutters 110. More specifically,
in this particular embodiment, the first roller cone 102 preferably
includes the first row 114a, the fifth row 114e, and the ninth row
114i of cutters 110. In this particular embodiment, the second
roller cone 104 preferably includes the second row 114b, the sixth
row 114f, and the tenth row 114j of cutters 110. In this particular
embodiment, the third roller cone 106 preferably includes the third
row 114c, the seventh row 114g, and the eleventh row 114k of
cutters 110. In this particular embodiment, the fourth roller cone
108 preferably includes the fourth row 114d, the eighth row 114h,
and the twelfth row 114l of cutters 110.
[0043] In the embodiment of the reamer tool having three roller
cones 102-106, each roller cones preferably has four of the rows
114a-114l of cutters 110. More specifically, in this particular
embodiment, the first roller cone 102 preferably includes the first
row 114a, the fourth row 114d, the seventh row 114g, and the tenth
row 114j of cutters 110. In this particular embodiment, the second
roller cone 104 preferably includes the second row 114b, the fifth
row 114e, the eighth row 114h, and the eleventh row 114k of cutters
110. In this particular embodiment, the third roller cone 106
preferably includes the third row 114c, the sixth row 114f, the
ninth row 114i, and the twelfth row 114l of cutters 110.
[0044] In both embodiments, dispersing the rows 114a-114l of
cutters 110 across multiple cones, provides adequate spacing
between the rows 114a-114l, while still providing an overlapping
cutter profile 112, thereby allowing shavings, or cuttings, to be
removed by drilling fluid or other processes known in the art. In
other words, the cutter profile 112 engages the working surface 44
with overlapping cutters 110, the rows 114a-114l of cutters 110
overlapping from one roller cone to the next. At the same time,
however, the rows 114a-114l on any one roller cone 102-108 are
adequately spaced to allow the cuttings to be removed. The
dispersion, distribution, and/or spacing of the cutters 110
themselves, as well as the rows 114a-114l of cutters 110, allows
the roller cones 102-108 to freely rotate without the cutters 110
coming into contact with one another.
[0045] In one embodiment of the reamer tool 100, dispersing the
rows 114a-114l of cutters 110 across multiple roller cones allows
the cutter profile 112 to engage the working surface 44 with
overlapping cutters 110, without the cutters 110 from one roller
cone meshing with the cutters 110 from another roller cone. This
allows the roller cones 102,104,106,108 to rotate independently of
each other. Spacing of the roller cones 102,104,106,108,
themselves, around the reamer tool 100, may aid in separating the
cutters 110 from different roller cones.
[0046] In any case, it can be seen that successive rows 114a-114l
of cutters 110 are located above and outwardly of previous cutter
rows such that each cutter row engages the wellbore in such a
manner as to incrementally expand the wellbore outwardly, as the
bottomhole assembly 10 is lowered into the wellbore. More
specifically, successive rows 114a-114l of cutters 110 are located
above and outwardly of previous cutter rows such that each cutter
row engages the wellbore in such a manner as to incrementally
expand the unconfined inner sidewall 40 outwardly. Still more
specifically, in one embodiment, a first cutter ring, or row, 114a
is configured to expand the unconfined inner sidewall 40 of the
wellbore, a second cutter ring 114b is located above and outwardly
of the first cutter ring 114a and configured to expand the
unconfined inner sidewall 40 as expanded by the first cutter ring
114a, and a third cutter ring 114c is located above and outwardly
of the second cutter ring and configured to expand the unconfined
inner sidewall as expanded by the second cutter ring.
[0047] Other and further embodiments utilizing one or more aspects
of the inventions described above can be devised without departing
from the spirit of Applicant's invention. For example, just as more
or fewer roller cones may be used, more or fewer rows of cutters
can be used on each roller cone. While the roller cones are
described as having equal numbers of rows of cutters, roller cones
having different numbers of rows of cutters could be used in some
embodiments. Further, in some embodiments, one or more of the
cutter rings, may be embodied as a cutter disk, a serrated disk, a
row or ring of milled and hardfaced teeth, and/or a row of tungsten
carbide inserts.
[0048] Additionally, or alternatively, in one embodiment, each
outer-most row of cutters, or cutter ring, on each roller cone
102,104,106,108 combine to contribute to the final inner sidewall
42 of the wellbore. For example, in an embodiment with four roller
cones 102,104,106,108, the ninth row 114i of cutters 110 on the
first roller cone 102, the tenth row 114j of cutters 110 on the
second roller cone 104, the eleventh row 114k of cutters 110 on the
third roller cone 106, and the twelfth row 114l of cutters 110 on
the fourth roller cone 108 all contribute to the final inner
sidewall 42 of the wellbore. In this case, the ninth row 114i of
cutters 110 may be longer and/or otherwise configured differently
from the twelfth row 114l of cutters 110. In other embodiments,
one, two, three, or more outer-most cutter rings contribute to the
final inner sidewall 42 of the wellbore. In any case, by having
multiple cutter rings contribute, this provides a smoother, more
uniform, and more consistently sized and shaped final inner
sidewall 42.
[0049] The order of steps can occur in a variety of sequences
unless otherwise specifically limited. The various steps described
herein can be combined with other steps, interlineated with the
stated steps, and/or split into multiple steps. Similarly, elements
have been described functionally and can be embodied as separate
components or can be combined into components having multiple
functions. Finally, the various methods and embodiments of the
reamer tool 100 can be included in combination with each other to
produce variations of the disclosed methods and embodiments.
Discussion of singular elements can include plural elements and
vice-versa. For example, in some embodiments, rather than one of
each individual cone 102,104,106,108 described above, there may be
two, spaced at approximately 180 degrees, three spaced at
approximately 120 degrees, four spaced at approximately 90 degrees,
or more, for each cone described above. More specifically, there
may be two or more first roller cones, configured and performing as
described above, but spaced 180 degrees across the reamer tool
100.
[0050] As discussed above, it is anticipated that the roller cones
will be substantially uniformly spaced around the reamer tool 100.
However, in one embodiment, four roller cones are spaced at 90
degrees, 90 degrees, 100 degrees, and 80 degrees, on center.
Therefore, the roller cones may be offset five, ten, fifteen, or
twenty degrees, or some included range, off otherwise uniform
spacing. This spacing applies to embodiments having singular and/or
multiple individual first, second, third, and/or fourth roller
cones 102,104,106,108.
[0051] The inventions have been described in the context of
preferred and other embodiments and not every embodiment of the
invention has been described. Obvious modifications and alterations
to the described embodiments are available to those of ordinary
skill in the art. The disclosed and undisclosed embodiments are not
intended to limit or restrict the scope or applicability of the
invention conceived of by the Applicants, but rather, in conformity
with the patent laws, Applicants intend to fully protect all such
modifications and improvements that come within the scope or range
of equivalent of the following claims.
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