U.S. patent application number 17/498591 was filed with the patent office on 2022-01-27 for method and apparatus for reaming well bore surfaces nearer the center of drift.
This patent application is currently assigned to Extreme Technologies, LLC. The applicant listed for this patent is Extreme Technologies, LLC. Invention is credited to Richard Earl Beggs, Robert Bradley Beggs, Lot William Short, JR..
Application Number | 20220025711 17/498591 |
Document ID | / |
Family ID | |
Filed Date | 2022-01-27 |
United States Patent
Application |
20220025711 |
Kind Code |
A1 |
Short, JR.; Lot William ; et
al. |
January 27, 2022 |
METHOD AND APPARATUS FOR REAMING WELL BORE SURFACES NEARER THE
CENTER OF DRIFT
Abstract
An apparatus to increase a diameter of a well bore includes a
drill pipe that includes a first end, a second end spaced apart
from the first end, and a longitudinal axis. A first reamer is
coupled to the drill pipe, the first reamer including a first
plurality of teeth and a first reamer axis spaced radially apart
from the longitudinal axis of the drill pipe. At least a second
reamer is coupled to the drill pipe and spaced longitudinally apart
from the first reamer. The at least a second reamer includes a
second plurality of teeth and a second reamer axis spaced radially
apart from the longitudinal axis of the drill pipe, the second
reamer axis being angularly offset from the first reamer axis such
that a drift diameter of the apparatus is smaller than a drill
diameter of the apparatus.
Inventors: |
Short, JR.; Lot William;
(Garland, TX) ; Beggs; Robert Bradley; (Rowlett,
TX) ; Beggs; Richard Earl; (Rowlett, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Extreme Technologies, LLC |
Vernal |
UT |
US |
|
|
Assignee: |
Extreme Technologies, LLC
Vernal
UT
|
Appl. No.: |
17/498591 |
Filed: |
October 11, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16286468 |
Feb 26, 2019 |
11156035 |
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17498591 |
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15601326 |
May 22, 2017 |
10508497 |
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16286468 |
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14454320 |
Aug 7, 2014 |
9657526 |
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15601326 |
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13517870 |
Jun 14, 2012 |
8813877 |
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14454320 |
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13441230 |
Apr 6, 2012 |
8851205 |
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13517870 |
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61473587 |
Apr 8, 2011 |
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International
Class: |
E21B 7/28 20060101
E21B007/28; E21B 10/26 20060101 E21B010/26 |
Claims
1. An apparatus configured to be positioned in at least one of a
drill string and a bottom hole assembly and adapted to increase a
diameter of a well bore as the apparatus is rotated, comprising: a
drill pipe that includes a first end, a second end spaced apart
from the first end, and a longitudinal axis that is aligned with a
longitudinal axis of at least one of the drill string and the
bottom hole assembly; a first reamer coupled to the drill pipe, the
first reamer including: a first plurality of teeth; a first reamer
axis spaced radially apart from the longitudinal axis of the drill
pipe; and at least a second reamer coupled to the drill pipe and
spaced longitudinally apart from the first reamer, the at least a
second reamer including: a second plurality of teeth; a second
reamer axis spaced radially apart from the longitudinal axis of the
drill pipe, the second reamer axis being angularly offset from the
first reamer axis such that a drift diameter of the apparatus is
smaller than a drill diameter of the apparatus.
2. The apparatus of claim 1, wherein the first reamer axis and the
second reamer axis are each a fixed distance from the longitudinal
axis of the drill pipe.
3. The apparatus of claim 1, wherein the second reamer axis is 180
degrees apart from the first reamer axis relative to the
longitudinal axis of the drill pipe.
4. The apparatus of claim 1, wherein at least one of the first
reamer and the at least a second reamer further comprises at least
one groove formed in a surface of the first reamer and the at least
a second reamer.
5. The apparatus of claim 4, wherein a long axis of the groove,
when viewed in profile, intersects at an acute angle the
longitudinal axis of the drill pipe as the longitudinal axis
extends downhole.
6. The apparatus of claim 1, wherein the first plurality of teeth
form a first plurality of sets of teeth, wherein each set of the
first plurality of sets of teeth is separated from an adjacent set
of teeth by a groove formed in a surface of the first reamer.
7. The apparatus of claim 1, wherein the second plurality of teeth
form a second plurality of sets of teeth, wherein each set of the
second plurality of sets of teeth is separated from an adjacent set
of teeth by a groove formed in a surface of the second reamer.
8. The apparatus of claim 7, wherein each set of the first
plurality of sets of teeth defines a blade.
9. The apparatus of claim 8, wherein each set of the second
plurality of sets of teeth defines a blade.
10. The apparatus of claim 8, wherein a width of the groove is
greater than a width of the blade.
11. The apparatus of claim 1, wherein a center of at least a first
tooth of the at least a second plurality of teeth is spaced at a
different circumferential location than a center of at least a
first tooth of the first plurality of teeth.
12. The apparatus of claim 1, wherein a first plane extending
through a center of each tooth of the first plurality of teeth,
when viewed in profile, intersects at an acute angle the
longitudinal axis of the drill pipe as the longitudinal axis
extends downhole.
13. The apparatus of claim 1, wherein at least the first plurality
of teeth covers approximately fifty percent of the circumference of
at least one of the first reamer and the at least a second
reamer.
14. The apparatus of claim 1, wherein the first plurality of teeth
are arranged along a spiral path along a surface of the first
reamer.
15. The apparatus of claim 1, wherein the second plurality of teeth
are arranged along a spiral path along a surface of the first
reamer.
16. The apparatus of claim 1, wherein at least one tooth of at
least one of the first plurality of teeth and the second plurality
of teeth is formed of one of carbide and diamond.
17. A method of increasing a drill diameter of a wellbore,
comprising: coupling the apparatus of claim 1 to a drill string and
to a bottom hole assembly; positioning the apparatus in the
wellbore; rotating the apparatus.
Description
PRIORITY CLAIM
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/286,468 entitled METHOD AND APPARATUS FOR
REAMING WELL BORE SURFACES NEARER THE CENTER OF DRIFT, filed Feb.
26, 2019, now U.S. Pat. No. 11,156,035, which in turn is a
continuation of U.S. patent application Ser. No. 15/601,326
entitled METHOD AND APPARATUS FOR REAMING WELL BORE SURFACES NEARER
THE CENTER OF DRIFT, filed May 22, 2017, now U.S. Pat. No.
10,508,497, which in turn is a continuation of U.S. patent
application Ser. No. 14/454,320 entitled METHOD AND APPARATUS FOR
REAMING WELL BORE SURFACES NEARER THE CENTER OF DRIFT, filed Aug.
7, 2014 and which issued as U.S. Pat. No. 9,657,526 on May 23,
2017, which in turn is a continuation of U.S. patent application
Ser. No. 13/517,870 entitled METHOD AND APPARATUS FOR REAMING WELL
BORE SURFACES NEARER THE CENTER OF DRIFT, filed Jun. 14, 2012 and
which issued as U.S. Pat. No. 8,813,877 on Aug. 26, 2014, which in
turn is a continuation of U.S. patent application Ser. No.
13/441,230 entitled METHOD AND APPARATUS FOR REAMING WELL BORE
SURFACES NEARER THE CENTER OF DRIFT, filed Apr. 6, 2012 and which
issued as U.S. Pat. No. 8,851,205 on Oct. 7, 2014, which in turn
claims priority to and the benefit of the filing date of U.S.
Provisional Patent Application Ser. No. 61/473,587 entitled METHOD
AND APPARATUS FOR REAMING WELL BORE SURFACES NEARER THE CENTER OF
DRIFT, filed Apr. 8, 2011, all of which are specifically and
entirely incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to methods and apparatus for
drilling wells and, more particularly, to a reamer and
corresponding method for enlarging the drift diameter and improving
the well path of a well bore.
BACKGROUND
[0003] Extended reach wells are drilled with a bit driven by a down
hole motor that can be steered up, down, left, and right. Steering
is facilitated by a bend placed in the motor housing above the
drill bit. Holding the drill string in the same rotational
position, such as by locking the drill string against rotation,
causes the bend to consistently face the same direction. This is
called "sliding". Sliding causes the drill bit to bore along a
curved path, in the direction of the bend, with the drill string
following that path as well.
[0004] Repeated correcting of the direction of the drill bit during
sliding causes friction between the well bore and the drill string
greater than when the drill string is rotated. Such corrections
form curves in the well path known as "doglegs". Referring to FIG.
1a, the drill string 10 presses against the inside of each dogleg
turn 12, causing added friction. These conditions can limit the
distance the well bore 14 can be extended within the production
zone, and can also cause problems getting the production string
through the well bore.
[0005] Similar difficulties can also occur during conventional
drilling, with a conventional drill bit that is rotated by rotating
the drill string from the surface. Instability of the drill bit can
cause a spiral or other tortuous path to be cut by the drill bit.
This causes the drill string to press against the inner surface of
resulting curves in the well bore and can interfere with extending
the well bore within the production zone and getting the production
string through the well bore.
[0006] When a dogleg, spiral path or tortuous path is cut by a
drill bit, the relatively unobstructed passageway following the
center of the well bore has a substantially smaller diameter than
the well bore itself. This relatively unobstructed passageway is
sometimes referred to as the "drift" and the nominal diameter of
the passageway is sometimes referred to as the "drift diameter".
The "drift" of a passageway is generally formed by well bore
surfaces forming the inside radii of curves along the path of the
well bore. Passage of pipe or tools through the relatively
unobstructed drift of the well bore is sometimes referred to as
"drift" or "drifting".
[0007] In general, to address these difficulties the drift diameter
has been enlarged with conventional reaming techniques by enlarging
the diameter 16 of the entire well bore. See FIG. 1a. Such reaming
has been completed as an additional step, after drilling is
completed. Doing so has been necessary to avoid unacceptable
increases in torque and drag during drilling. Such additional
reaming runs add considerable expense and time to completion of the
well. Moreover, conventional reaming techniques frequently do not
straighten the well path, but instead simply enlarge the diameter
of the well bore.
[0008] Accordingly, a need exists for a reamer that reduces the
torque required and drag associated with reaming the well bore.
[0009] A need also exists for a reamer capable of enlarging the
diameter of the well bore drift passageway and improving the well
path, without needing to enlarge the diameter of the entire well
bore.
SUMMARY
[0010] To address these needs, the invention provides a method and
apparatus for increasing the drift diameter and improving the well
path of the well bore. This is accomplished, in one embodiment, by
cutting away material primarily forming surfaces nearer the center
of the drift. Doing so reduces applied power, applied torque and
resulting drag compared to conventional reamers that cut into all
surfaces of the well bore.
[0011] An apparatus is configured to be positioned in at least one
of a drill string and a bottom hole assembly and adapted to
increasing a diameter of a well bore. The apparatus includes a
drill pipe that includes a first end, a second end spaced apart
from the first end, and a longitudinal axis that is aligned with a
longitudinal axis of at least one of the drill string and the
bottom hole assembly. A first reamer and at least a second reamer
are coupled to the drill pipe, wherein the second reamer is spaced
longitudinally apart from the first reamer, and wherein the second
reamer is positioned diametrically opposed to the first reamer on
the drill pipe. A first plurality of cutting teeth are positioned
about each of the first reamer and the at least a second reamer,
wherein a top of each successive tooth in a direction counter to a
rotation of the apparatus in the well bore extends a radial
distance from the longitudinal axis that is one of a) equal to a
radial distance from the longitudinal axis of a preceding tooth and
b) greater than the radial distance from the longitudinal axis of
the preceding tooth. Each tooth of the first plurality of cutting
teeth is positioned at a different circumferential location about
each reamer from any adjacent teeth of the first plurality of
teeth. At least a second plurality of cutting teeth are positioned
about each of the first reamer and the at least a second reamer,
the at least a second plurality of cutting teeth being spaced
longitudinally apart from the first plurality of cutting teeth.
[0012] The at least a second plurality of cutting teeth optionally
includes a top of each successive tooth in a direction counter to a
rotation of the apparatus in the well bore that extends a radial
distance from the longitudinal axis that is one of a) equal to a
radial distance from the longitudinal axis of a preceding tooth and
b) greater than the radial distance from the longitudinal axis of
the preceding tooth. Optionally, each tooth of the second plurality
of cutting teeth is positioned at a different circumferential
location about each reamer from any adjacent teeth of the at least
a second plurality of teeth.
[0013] At least one of the first reamer and the at least a second
reamer optionally may include at least one groove formed in a
surface of the first reamer and the at least a second reamer. A
long axis of the groove, when viewed in profile, may intersect at
an acute angle the longitudinal axis of the drill pipe as the
longitudinal axis extends downhole. An uphole portion of the at
least one groove may be spaced longitudinally apart and may be at
substantially a same circumferential position as a downhole portion
of at least a second groove formed in the surface of at least one
of the first reamer and the at least a second reamer.
[0014] Optionally, the first plurality of cutting teeth and the at
least a second plurality of cutting teeth, in combination, define a
plurality of sets of teeth, and wherein each set defines a blade. A
center of each tooth of a first set of teeth of the plurality of
sets of teeth may be longitudinally spaced apart and positioned at
a different circumferential location from a center of each tooth of
an adjacent set of teeth of the plurality of sets of teeth. The at
least one groove optionally separates a first set of teeth of the
plurality of sets of teeth from at least a second set of teeth of
the plurality of sets of teeth. A width of the at least one groove
may be greater than a width of at least one blade defined by a set
of the plurality of sets of teeth.
[0015] Optionally, each successive tooth of the first plurality of
teeth is positioned at one a) the same longitudinal position as the
preceding tooth and b) longitudinally spaced apart from the
preceding tooth by a distance measured from a center of the
preceding tooth that is less than a radius of the preceding
tooth.
[0016] Optionally, at least a first tooth of the at least a second
plurality of teeth is spaced longitudinally apart from at least a
first tooth of the first plurality of teeth by a distance measured
from a center of the at least a first tooth of the first plurality
of teeth that is one of a) equal to and b) greater than a radius of
the at least a first tooth of the first plurality of teeth. The at
least the first tooth of the at least a second plurality of teeth
may be spaced longitudinally apart from at least a second tooth of
the first plurality of teeth by a distance measured from a center
of the at least a second tooth of the first plurality of teeth that
is one of a) equal to and b) greater than a radius of the at least
a second tooth of the first plurality of teeth.
[0017] A center of at least a first tooth of the at least a second
plurality of teeth may be spaced at a different circumferential
location than a center of at least a first tooth of the first
plurality of teeth.
[0018] A first plane may extend through a center of each tooth of
the first plurality of teeth, when viewed in profile, and intersect
at an acute angle the longitudinal axis of the drill pipe as the
longitudinal axis extends downhole.
[0019] Optionally, at least the first plurality of cutting elements
covers approximately fifty percent of the circumference of at least
one of the first reamer and the at least a second reamer. The at
least the first plurality of cutting elements also may be arranged
along a spiral path along a surface of at least one of the first
reamer and the at least a second reamer.
[0020] The foregoing has outlined rather broadly the features of
the present disclosure in order that the detailed description that
follows may be better understood. Additional features and
advantages of the disclosure will be described hereinafter, which
form the subject of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order that the manner in which the above-recited and
other enhancements and objects of the disclosure are obtained, a
more particular description of the disclosure briefly described
above will be rendered by reference to specific embodiments thereof
which are illustrated in the appended drawings. Understanding that
these drawings depict only typical embodiments of the disclosure
and are therefore not to be considered limiting of its scope, the
disclosure will be described with additional specificity and detail
through the use of the accompanying drawings in which:
[0022] FIGS. 1a and 1b are a cross-section elevations of a
horizontal well bore;
[0023] FIG. 2 is a representation of a well bore illustrating drift
diameter relative to drill diameter;
[0024] FIG. 3 is a representation an eccentric reamer in relation
to the well bore shown in FIG. 2;
[0025] FIG. 4 is a magnification of the downhole portion of the top
reamer;
[0026] FIG. 5 is illustrates the layout of teeth along a downhole
portion of the bottom reamer illustrated in FIG. 1;
[0027] FIG. 6 is an end view of an eccentric reamer illustrating
the eccentricity of the reamer in relation to a well bore
diameter;
[0028] FIG. 7 is an end view of two eccentric reamers in series,
illustrating the eccentricity of the two reamers in relation to a
well bore diameter;
[0029] FIG. 8 illustrates the location and arrangement of Sets 1,
2, 3 and 4 of teeth on another reamer embodiment;
[0030] FIG. 9 illustrates the location and arrangement of Sets 1,
2, 3 and 4 of teeth on another reamer embodiment;
[0031] FIG. 10 is a perspective view illustrating an embodiment of
a reamer having four sets of teeth;
[0032] FIG. 11 is a geometric diagram illustrating the arrangement
of cutting teeth on an embodiment of a reamer;
[0033] FIG. 12A-12D illustrate the location and arrangement of
Blades 1, 2, 3, and 4 of cutting teeth;
[0034] FIG. 13 is a side view of a reamer tool showing the cutting
teeth and illustrating a side cut area; and
[0035] FIGS. 14A-14D are side views of a reamer tool showing the
cutting teeth and illustrating a sequence of Blades 1, 2, 3, and 4
coming into the side cut area and the reamer tool rotates.
[0036] The drawings are not necessarily to scale.
DETAILED DESCRIPTION
[0037] In the following discussion, numerous specific details are
set forth to provide a thorough understanding of the present
invention. However, those skilled in the art will appreciate that
the present invention may be practiced without such specific
details. In other instances, well-known elements have been
illustrated in schematic or block diagram form in order not to
obscure the present invention in unnecessary detail. Additionally,
for the most part, specific details, and the like have been omitted
inasmuch as such details are not considered necessary to obtain a
complete understanding of the present invention, and are considered
to be within the understanding of persons of ordinary skill in the
relevant art.
[0038] The following definitions and explanations are meant and
intended to be controlling in any future construction unless
clearly and unambiguously modified in the following examples or
when application of the meaning renders any construction
meaningless or essentially meaningless. In cases where the
construction of the term would render it meaningless or essentially
meaningless, the definition should be taken from Webster's
Dictionary 3.sup.rd Edition.
[0039] The terms "up" and "down"; "upper" and "lower"; "upward" and
downward"; "above" and "below"; and other like terms as used herein
refer to relative positions to one another and are not intended to
denote a particular direction or spatial orientation or perspective
view
[0040] FIG. 1b is a cross-section elevation of a horizontal well
bore 100, illustrating an embodiment of the invention employing a
top eccentric reamer 102 and a bottom eccentric reamer 104. The top
reamer 102 and bottom reamer 104 are preferably of a similar
construction and may be angularly displaced by approximately
180.degree. on a drill string 106. This causes cutting teeth 108 of
the top reamer 102 and cutting teeth 110 of the bottom reamer 104
to face approximately opposite directions. The reamers 102 and 104
may be spaced apart and positioned to run behind a bottom hole
assembly (BHA). In one embodiment, for example, the eccentric
reamers 102 and 104 may be positioned within a range of
approximately 100 to 150 feet from the BHA. Although two reamers
are shown, a single reamer or a larger number of reamers could be
used in the alternative.
[0041] As shown in FIG. 1b, the drill string 106 advances to the
left as the well is drilled. As shown in FIG. 2, the well bore 100
may have a drill diameter D1 of 6 inches and a drill center 116.
The well bore 100 may have a drift diameter D2 of 55/8 inches and a
drift center 114. The drift center 114 may be offset from the drill
center 116 by a fraction of an inch. Any point P on the inner
surface 112 of the well bore 100 may be located at a certain radius
R1 from the drill center 116 and may also be located at a certain
radius R2 from the drift center 114. As shown in FIG. 3, in which
reamer 102 is shown having a threaded center C superimposed over
drift center 114, each of the reamers 102 (shown) and 104 (not
shown) preferably has an outermost radius R3, generally in the area
of its teeth 108, less than the outermost radius RD1 of the well
bore. However, the outermost radius R3 of each reamer is preferably
greater than the distance RD2 of the nearer surfaces from the
center of drift 114. The cutting surfaces of each of the top and
bottom reamers preferably comprise a number of carbide or diamond
teeth 108, with each tooth preferably having a circular cutting
surface generally facing the path of movement PM of the tooth
relative to the well bore as the reamer rotates and the drill
string advances down hole.
[0042] In FIG. 1b, the bottom reamer 104 begins to engage and cut a
surface nearer the center of drift off the well bore 100 shown. As
will be appreciated, the bottom reamer 104, when rotated, cuts away
portions of the nearer surface 112A of the well bore 100, while
cutting substantially less or none of the surface 112B farther from
the center of drift, generally on the opposite side of the well.
The top reamer 102 performs a similar function, cutting surfaces
nearer the center of drift as the drill string advances. Each
reamer 102 and 104 is preferably spaced from the BHA and any other
reamer to allow the centerline of the pipe string adjacent the
reamer to be offset from the center of the well bore toward the
center of drift or aligned with the center of drift.
[0043] FIG. 4 is a magnification of the downhole portion of the top
reamer 102 as the reamer advances to begin contact with a surface
112 of the well bore 100 nearer the center of drift 114. As the
reamer 102 advances and rotates, the existing hole is widened along
the surface 112 nearer the center of drift 114, thereby widening
the drift diameter of the hole. In an embodiment, a body portion
107 of the drill string 106 may have a diameter DB of 51/4 inches,
and may be coupled to a cylindrical portion 103 of reamer 102, the
cylindrical portion 103 having a diameter DC of approx. 43/4
inches. In an embodiment, the reamer 102 may have a "DRIFT"
diameter DD of 53/8 inches, and produce a reamed hole having a
diameter DR of 61/8 inches between reamed surfaces 101. It will be
appreciated that the drill string 106 and reamer 102 advance
through the well bore 100 along a path generally following the
center of drift 114 and displaced from the center 116 of the
existing hole.
[0044] FIG. 5 illustrates the layout of teeth 110 along a downhole
portion of the bottom reamer 104 illustrated in FIG. 1. Four sets
of teeth 110, Sets 110A, 110B, 110C and 110D, are angularly
separated about the exterior of the bottom reamer 104. FIG. 5 shows
the position of the teeth 110 of each Set as they pass the
bottom-most position shown in FIG. 1b when the bottom reamer 104
rotates. As the reamer 104 rotates, Sets 110A, 110B, 110C and 110D
110A, 110B, 110C and 110D pass the bottom-most position in
succession. The Sets 110A, 110B, 110C and 110D of teeth 110 are
arranged on a substantially circular surface 118 having a center
120 eccentrically displaced from the center of rotation of the
drill string 106.
[0045] Each of the Sets 110A, 110B, 110C and 110D of teeth 110 is
preferably arranged along a spiral path along the surface of the
bottom reamer 104, with the downhole tooth leading as the reamer
104 rotates (e.g., see FIG. 6). Sets 110A and 110B of the reamer
teeth 110 are positioned to have outermost cutting surfaces forming
a 61/8 inch diameter path when the pipe string 106 is rotated. The
teeth 110 of Set 110B are preferably positioned to be rotated
through the bottom-most point of the bottom reamer 104 between the
rotational path of the teeth 110 of Set 110A. The teeth 110 of Set
110C are positioned to have outermost cutting surfaces forming a
six inch diameter when rotated, and are preferably positioned to be
rotated through the bottom-most point of the bottom reamer between
the rotational path of the teeth 110 of Set 110B. The teeth 110 of
Set 110D are positioned to have outermost cutting surfaces forming
a 57/8 inch diameter when rotated, and are preferably positioned to
be rotated through the bottom-most point of the bottom reamer 104
between the rotational path of the teeth 110 of Set 110C.
[0046] FIG. 6 illustrates one eccentric reamer 104 having a drift
diameter D3 of 55/8 inches and a drill diameter D4 of 6 1/16
inches. When rotated about the threaded axis C, but without a
concentric guide or pilot, the eccentric reamer 104 may be free to
rotate about its drift axis C2 and may act to side-ream the
near-center portion of the dogleg in the borehole. The side-reaming
action may improve the path of the wellbore instead of just opening
it up to a larger diameter.
[0047] FIG. 7 illustrates a reaming tool 150 having two eccentric
reamers 104 and 102, each eccentric reamer having a drift diameter
D3 of 55/8 inches and a drill diameter D4 of 6 1/16 inches. The two
eccentric reamers may be spaced apart by ten hole diameters or
more, on a single body, and synchronized to be 180 degrees apart
relative to the threaded axis of the body. The reaming tool 150
having two eccentric reamers configured in this way, may be able to
drift through a 55/8 inch hole when sliding and, when rotating, one
eccentric reamer may force the other eccentric reamer into the hole
wall. An eccentric reaming tool 150 in this configuration has three
centers: the threaded center C coincident with the threaded axis of
the reaming toll 150, and two eccentric centers C2, coincident with
the drift axis of the bottom eccentric reamer 104, and C3,
coincident with a drift axis of the top eccentric reamer 102.
[0048] FIGS. 8 and 9 illustrate the location and arrangement of
Sets 1, 2, 3 and 4 of teeth on another reamer embodiment 200. FIG.
8 illustrates the relative angles and cutting diameters of Sets 1,
2, 3, and 4 of teeth. As shown in FIG. 8, Sets 1, 2, 3 and 4 of
teeth are each arranged to form a path of rotation having
respective diameters of 55/8 inches, 6 inches, 61/8 inches and 61/8
inches. FIG. 9 illustrates the relative position of the individual
teeth of each of Sets 1, 2, 3 and 4 of teeth. As shown in FIG. 9,
the teeth of Set 2 are preferably positioned to be rotated through
the bottom-most point of the reamer between the rotational path of
the teeth of Set 1. The teeth of Set 3 are preferably positioned to
be rotated through the bottom-most point of the reamer between the
rotational path of the teeth of Set 2. The teeth of Set 4 are
preferably positioned to be rotated through the bottom-most point
of the reamer between the rotational path of the teeth of Set
3.
[0049] FIG. 10 illustrates an embodiment of a reamer 300 having
four sets of teeth 310, with each set 310A, 310B, 310C, and 310D
arranged in a spiral orientation along a curved surface 302 having
a center C2 eccentric with respect to the center C of the drill
pipe on which the reamer is mounted. Adjacent and in front of each
set of teeth 310 is a groove 306 formed in the surface 302 of the
reamer. The grooves 306 allow fluids, such as drilling mud for
example, and cuttings to flow past the reamer and away from the
reamer teeth during operation. The teeth 310 of each set 310A,
310B, 310C, and 310D may form one of four "blades" for cutting away
material from a near surface of a well bore. The set 310A may form
a first blade, or Blade 1. The set 310B may form a second blade,
Blade 2. The set 310C may form a third blade, Blade 3. The set 310D
may form a fourth blade, Blade 4. The configuration of the blades
and the cutting teeth thereof may be rearranged as desired to suit
particular applications, but may be arranged as follows in an
exemplary embodiment.
[0050] Turning now to FIG. 11, the tops of the teeth 310 in each of
the two eccentric reamers 300, or the reamers 102 and 104, rotate
about the threaded center of the reamer tool and may be placed at
increasing radii starting with the #1 tooth at 2.750'' R. The radii
of the teeth may increase by 0.018'' every five degrees through
tooth #17 where the radii become constant at the maximum of
3.062'', which corresponds to the 61/8'' maximum diameter of the
reamer tool.
[0051] Turning now to FIGS. 12A-12D, the reamer tool may be
designed to side-ream the near side of a directionally near
horizontal well bore that is crooked in order to straighten out the
crooks. As shown in FIG. 12A-12D, 30 cutting teeth numbered 1
through 30 may be distributed among Sets 310A, 310B, 310C, and 310D
of cutting teeth forming four blades. As plotted in FIG. 11, the
cutting teeth numbered 1 through 8 may form Blade 1, the cutting
teeth numbered 9 through 15 may form Blade 2, the cutting teeth
numbered 16 through 23 may form Blade 3, and the cutting teeth
numbered 24 through 30 may form Blade 4. As the 51/4'' body 302 of
the reamer is pulled into the near side of the crook, the cut of
the rotating reamer 300 may be forced to rotate about the threaded
center of the body and cut an increasingly larger radius into just
the near side of the crook without cutting the opposite side. This
cutting action may act to straighten the crooked hole without
following the original bore path.
[0052] Turning now to FIG. 13, the reamer 300 is shown with the
teeth 310A of Blade 1 on the left-hand side of the reamer 300 as
shown, with the teeth 310B of Blade 2 following behind to the right
of Blade 1, the teeth 310C of Blade 3 following behind and to the
right of Blade 2, and the teeth 310D of Blade 4 following behind
and to the right of Blade 3. The teeth 310A of Blade 1 are also
shown in phantom, representing the position of teeth 310A of Blade
1 compared to the position of teeth 310D of Blade 4 on the
right-hand side of the reamer 300, and at a position representing
the "Side Cut" made by the eccentric reamer 300.
[0053] Turning now to FIGS. 14A-14D, the extent of each of Blade 1,
Blade 2, Blade 3, and Blade 4 is shown in a separate figure. In
each of the FIG. 14A-14D, the reamer 300 is shown rotated to a
different position, bringing a different blade into the "Side Cut"
position SC, such that the sequence of views 14A-14D illustrate the
sequence of blades coming into cutting contact with a near surface
of a well bore. In FIG. 14A, Blade 1 is shown to cut from a 51/4''
diameter to a 51/2'' diameter, but less than a full-gage cut. In
FIG. 14B, Blade 2 is shown to cut from a 53/8'' diameter to a 6''
diameter, which is still less than a full-gage cut. In FIG. 14C,
Blade 3 is shown to cut a "Full Gage" diameter, which may be equal
to 61/8'' in an embodiment. In FIG. 14D, Blade 4 is shown to cut a
"Full gage" diameter, which may be equal to 61/8'' in an
embodiment.
[0054] The location and arrangement of Sets of teeth on an
embodiment of an eccentric reamer as described above, and teeth
within each set, may be rearranged to suit particular applications.
For example, the alignment of the Sets of teeth relative to the
centerline of the drill pipe, the distance between teeth and Sets
of teeth, the diameter of rotational path of the teeth, number of
teeth and Sets of teeth, shape and eccentricity of the reamer
surface holding the teeth and the like may be varied.
[0055] Having thus described the present invention by reference to
certain of its preferred embodiments, it is noted that the
embodiments disclosed are illustrative rather than limiting in
nature and that a wide range of variations, modifications, changes,
and substitutions are contemplated in the foregoing disclosure and,
in some instances, some features of the present invention may be
employed without a corresponding use of the other features. Many
such variations and modifications may be considered desirable by
those skilled in the art based upon a review of the foregoing
description of preferred embodiments. Accordingly, it is
appropriate that the appended claims be construed broadly and in a
manner consistent with the scope of the invention.
[0056] All of the compositions and methods disclosed and claimed
herein can be made and executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this disclosure have been described in terms of preferred
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the compositions and methods and in
the steps or in the sequence of steps of the methods described
herein without departing from the concept, spirit and scope of the
disclosure. All such similar substitutes and modifications apparent
to those skilled in the art are deemed to be within the spirit,
scope and concept of the disclosure as defined by the appended
claims.
* * * * *