U.S. patent application number 13/129317 was filed with the patent office on 2011-09-15 for centralized bi-center reamer and method of use.
Invention is credited to Allen Kent Rives.
Application Number | 20110220416 13/129317 |
Document ID | / |
Family ID | 42170381 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110220416 |
Kind Code |
A1 |
Rives; Allen Kent |
September 15, 2011 |
Centralized Bi-Center Reamer and Method of Use
Abstract
This apparatus provides an underreamer and a reamer or hole
opener to enlarge an existing pilot hole thereby permitting further
operation to be carried out in a well bore. The underreamer can be
inserted down a well bore in the unexpanded condition and, since
the radius of the eccentrically mounted cutters of the reamer or
hole opener added to the radius of the unexpanded underreamer
equals the pass through diameter (the inner diameter of the
restriction), the entire assembly or apparatus can be inserted to
the position requiring enlarging. The underreamer is expanded to
engage the adjacent wall of the well bore and stabilize the reamer
as it enlarges the hole. Since movement resulting from the lateral
forces are restrained by the centralizer/underreamer as well as the
bullnose or smaller pilot hole drill bit, the bi-center reamer can
readily open the well bore to the desired diameter without lateral
deviation.
Inventors: |
Rives; Allen Kent; (Cypress,
TX) |
Family ID: |
42170381 |
Appl. No.: |
13/129317 |
Filed: |
November 16, 2009 |
PCT Filed: |
November 16, 2009 |
PCT NO: |
PCT/US09/64558 |
371 Date: |
May 13, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61114922 |
Nov 14, 2008 |
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Current U.S.
Class: |
175/57 ;
175/265 |
Current CPC
Class: |
E21B 17/1078 20130101;
E21B 17/1057 20130101; E21B 17/1021 20130101 |
Class at
Publication: |
175/57 ;
175/265 |
International
Class: |
E21B 7/00 20060101
E21B007/00; E21B 10/34 20060101 E21B010/34 |
Claims
1. An apparatus for enlarging a bore hole comprising: a
selectively-engageable underreaming centralizer to engage a well
bore on a proximal portion of a bottom hole assembly; and, one or
more rolling cutter cones mounted eccentrically on a distal reamer
portion of the bottom hole assembly such that the outer diameter of
the reamer portion is smaller than the inner diameter of a passage
through which the apparatus passes on a distal portion of the
bottom hole assembly.
2. The apparatus of claim 1 wherein the selectively-engageable
underreaming centralizer provides hard-facing on a face of a
plurality of well bore engaging arms.
3. The apparatus of claim 1 wherein the selectively-engageable
underreaming centralizer provides one or more rolling cutter cones
for engaging the well bore.
4. (canceled)
5. (canceled)
6. The apparatus of claim 1 wherein the underreaming centralizer
and the eccentric roller cone portion of the bottom hole assembly
are on two tubular bodies connected together.
7. The apparatus of claim 1 wherein the underreaming centralizer
and the eccentric roller cone portion of the bottom hole assembly
are fabricated on an integral body.
8. The apparatus of claim 1 additionally providing a bit connected
to the distal eccentric roller cone portion of the bottom hole
assembly.
9. The apparatus of claim 1 additionally providing a bull-nose plug
connected to the distal eccentric roller cone portion of the bottom
hole assembly.
10. A method for enlarging a pilot bore hole comprising: inserting
a underreaming centralizer and an eccentric roller cone assembly
apparatus in a zone to be enlarged while keeping the underreaming
centralizer arms from deployment; opening the underreaming
centralizer arms by increasing hydraulic pressure to thereby engage
the eccentric roller cone assembly into engagement with a section
of the pilot bore hole and centralize and stabilize the roller cone
assembly as it engages the bore hole; and, rotating the
underreaming centralizer and eccentric roller cone assembly
combination to enlarge the pilot bore hole.
11. The method of claim 10 further comprising rotating the bottom
hole assembly while increasing pump pressure on the underreaming
centralizer to fully extend the underreaming centralizer arms to
engage the well bore before advancing the underreaming centralizer
and eccentric roller cone assembly in the well bore.
Description
[0001] This application relates to a centralized bi-center reamer
and a method for drilling and enlarging a hole with such device;
specifically, to a bottom hole assembly that provides a
centralizing underreamer or roller assembly to centralize a
bi-center reamer, which enlarges a drilled hole mounted above.
BACKGROUND
[0002] During the drilling of subterranean holes for the
exploration and production of oil and gas, by way of example, it
may be useful to both drill and enlarge a smaller diameter or pilot
hole. At other times, a small diameter or pilot hole has been
drilled which must be enlarged to properly install casing in the
well. In a normal bi-center application, the pilot hole provides
the centralizing element guide to keep a bi-center bit centered so
it will ream a larger hole. Although inherently unstable,
bi-centered bits having shear-type (PDC) cutter elements which
enlarge the bore-hole have long been used in the industry. See, for
example, U.S. Pat. No. 5,678,644 for a Bi-Center and Bit Method for
Enhancing Stability issued Oct. 21, 1997 and U.S. Pat. No.
5,957,223 for a Bi-Center Bit with Enhanced Stabilizing Features
issued Sep. 28, 1999. Bi-centered technology has a tendency to move
off the true desired line of drilling because of the nature of the
eccentric side forces acting on the tools. The present disclosure
relates to an apparatus and method for using the bi-centered
technology for underreaming while overcoming this inherent tendency
for the bi-center assembly carried on the bottom hole assembly
(BHA) to move off the desired direction of travel.
[0003] To run a conventional bi-center bit, normally there is no
pilot hole and the hole is drilled and reamed simultaneously. The
drill bit and reamer diameter size is always smaller than the
pass-through diameter. In many cases, however, drillers need to
open a hole that has been previously drilled to the pass-through
diameter or just slightly smaller. In this case, an underreamer is
normally run to open the hole to the desired size that is larger
than the pass-through diameter. The preferred embodiment of the
present invention utilizes one or more fixed low-torque cutters
that are cantilevered from the bottom hole assembly (BHA). This
avoids using an expandable arm as found in a standard underreamer
that is inherently weaker than a fixed cutter cantilevered from a
body. Alternatively, the centralized bi-center underreamer could
utilize a shear type polycrystalline diamond compacts (PDC)
underreamer, which would be centralized and stabilized in the
center of the well bore by the accompanying
centralizer/underreamer.
SUMMARY OF INVENTION
[0004] An apparatus for enlarging a bore hole provides a
selectively-engageable centralizer to engage a well bore on a
proximal portion of a bottom hole assembly and a bi-centered reamer
on a distal portion of the bottom hole assembly. This apparatus can
be fabricated so the selectively-engageable centralizer provides
hard-facing on a face of a plurality of well bore engaging arms,
thereby preventing wear from movement over the well bore as well as
starting the underreaming function of the tool assembly.
[0005] Alternatively, this apparatus could provide a
selectively-engageable centralizer having a plurality of rolling
cutter cones for engaging the well bore. This apparatus could
alternatively be fabricated the bi-centered reamer is composed on
one large roller or several smaller roller cutter cones mounted
eccentrically on the reamer portion of the bottom hole assembly
such that the outer diameter of the reamer portion is smaller than
the inner diameter of a passage through which the apparatus passes
on the distal portion of the bottom hole assembly.
[0006] The apparatus can also be fabricated wherein the bi-centered
reamer is a scraping reamer have a plurality of PDC buttons on a
portion of the extending reamer eccentric body. The apparatus can
be fabricated to provide the centralizer and the reamer portion of
the bottom hole assembly on two tubular bodies connected together
or, alternatively, fabricated on an integral body.
[0007] The apparatus can additionally provide a bit connected to
the reamer portion of the bottom hole assembly or may be inserted
in a well bore utilizing a bull-nose plug connected to the reamer
portion of the bottom hole assembly.
[0008] A method for enlarging a pilot bore hole is also disclosed
herein comprising inserting a centralizer and an bi-center
underreamer apparatus in a zone to be enlarged while keeping the
centralizer arms from deployment; opening the centralizer arms by
increasing hydraulic pressure to thereby centralize and stabilize
the bi-center underreamer as it engages the bore hole; and,
rotating the centralizer and reamer combination to enlarge the
pilot bore hole. This method can further comprise comprising
rotating the BHA while increasing pump pressure on the centralizer
to fully extend the centralizer arms to engage the well bore before
advancing the centralizer and bi-centered underreamer in the well
bore.
DRAWINGS
[0009] FIG. 1 is a schematic cross-sectional view of an embodiment
of the centralized bi-center reamer assembly.
[0010] FIG. 2 is a schematic end view of the relative spacing of
the centralized bi-center reamer assembly.
[0011] FIG. 3 is a schematic cross-sectional view of an alternative
embodiment of the centralized bi-center reamer assembly utilizing
cones on the underreamer assembly.
[0012] FIG. 4 is a partial schematic view of a PDC blade reamer
portion of the embodiment of this present disclosure.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
[0013] The present application relates to a centralized bi-center
reamer having eccentrically spaced cutters run below a conventional
underreamer operating as a centralizer used to stabilize and
centralize the bi-center reamer in the pilot hole. This embodiment
of the present invention is an apparatus for insertion through a
smaller diameter casing or tubing (not shown) with the centralizer
arms disengaged from the well bore wall 52. As shown in FIG. 1,
upon reaching the desired portion of the well bore 70, the arms 30
having a wall-engaging pad 31 of the expandable centralizer or
underreamer 10 located on a proximal portion of the BHA, are
selectively expanded to engage the well bore wall 52 thereby
stabilizing and centralizing the bi-center reamer or hole opener 20
located on the distal portion of the BHA below. These wall-engaging
pads 31 are placed on the arms 30 of the underreamer to substitute
for the roller cutters or PDC cutter elements normally found at
this location. The manner of fabrication and deployment of the
underreamer is well known to those skilled in the art and the
substitution of the pads 31 on arms 30 for the cutters could be
easily accomplished by a person having ordinary skills in the
fabrication of this type of tool. The arms 30 are selectively
engageable with the well bore 52 by increasing hydraulic pressure
on a piston arrangement which moves the arms 30 into engagement in
a fashion found in a number of prior art underreamer devices.
[0014] The underreamer or centralizer arms 30 are not primarily
intended to cut the formation, but serve to centralize and
stabilize the bi-center reamer portion in the center of the hole
thereby allowing the hole or well bore to be opened to the desired
diameter. However, the hard-facing on the pads 31 on the extendable
arms 30 will function to minimally underream the formation in the
well bore. It is also suggested that the underreamer be allowed to
reach full extension through rotation while increasing pump
pressure to move the arms into full contact before moving the
reamer 20 forward in the well bore 70. Expandable rollers may be
substituted to centralize and stabilize the reamer while it
performs its primary function.
[0015] Alternatively, cutter cones 33, as shown in FIG. 3, could be
deployed to roll against the adjacent well bore wall 52 to
centralize and stabilize the bi-center reamer or hole opener 20
having the integral cantilevered cutter arms 42. In most uses of a
bi-center arrangement for reaming after drilling, the drill bit
provides some stabilizing force to counteract the lateral forces
resulting from the action of the bi-center reamer. In the present
disclosure, this stabilizing effect need not be present since the
original drill bit is not necessarily deployed with the reamer in
the existing pilot hole. A bull nose or smaller drill bit cone (not
shown) can be deployed to permit the flow of fluid through the well
bore and to remove cuttings from the reamer up through the annulus
70. The description found in U.S. Pat. No. 5,957,223 discusses
these lateral forces in detail. As previously noted, the
stabilizing and centralizing action of the centralizer or
underreamer 10 counteracts the lateral forces, which prevent clean
and straight hole enlargement by the bi-center reamer 20. Without
this centralizing and stabilizing action of the underreamer, the
eccentrically located cutters on the reamer would move off the wall
of the pilot hole 50 deviating from the central axis of the pilot
hole and spiraling out of directional control.
[0016] The reamer or hole opener portion 20 of this apparatus
enlarges a pre-existing pilot hole 50 in a well bore to a larger
hole size 52. The cantilevered fixed post 42, journal 43 and cutter
body 40 are inherently stronger than typical underreamer extendable
arm cutters. The present embodiment adds the strength of these
fixed cantilevered arms to the bi-center technology permitting
deployment through smaller diameter casing or tubing thereby
permitting enlarging of particularly difficult bore holes.
[0017] As more fully shown in FIG. 2, by way of example only and
without limitation to the exact dimensions shown therein, a 26 inch
pilot hole 50 is opened to a 32 inch hole 52 by the reaming action
of the eccentrically placed integral bodied cutters 40 which can be
passed through a 28 inch inner diameter of a 30 inch casing or
tubing 55. The underreamer body 10 has a 22-inch outer diameter and
can therefore be easily transported by the drill string to the
desired location through the casing. As shown in FIG. 2, the two
eccentrically spaced cutter cones are only 60.degree. apart
allowing their end profile to fit within the 28 inch inner diameter
of the 30 inch casing or tubing, i.e., the pass-through diameter.
As shown in FIGS. 1 and 3, each cone is mounted on an integral
journal 43 formed in the outer surface of the reamer portion of the
body 20. Alternatively, a single larger cutter cone could be
mounted eccentrically on the reamer portion 20 of the body without
departing from the spirit or intent of this disclosure. The choice
of materials for the cutters is well known to those skilled in the
hole opener art and can include, without limitation, PDC elements
or hardened teeth or cutter elements or hard-facing placed on the
exterior surface of each cone.
[0018] The choice of the number and size of the cutter cones is
also derived from knowledge of those experienced in this art and
although the preferred embodiment shows two cones, and as noted the
devices could conceivable be fabricated with a single larger cone
or several smaller cones. The limitation on the number of cones
used is the pass-through size, which must be accommodated. The
benefits of a fixed post cantilevered reamer or hole opener are
more fully described in U.S. Pat. No. 5,992,542, which is
incorporated herein by reference as if copied herein verbatim.
[0019] Returning to FIG. 1, additional features may be added to the
apparatus to accomplish the enlargement of the pilot hole. For
example, a hydraulic jet 60 can be positioned on the reamer or hole
opener portion 20 of the apparatus on a side opposite the
eccentrically positioned cutters 40 to clear cuttings up the
annulus 70. Additionally, while underreamer body 10 and reamer or
hole opener body 20 are shown in FIG. 1 as being connected by
threaded connection 80, this apparatus could alternatively be
fabricated as an integral body without departing from the spirit or
intent of this disclosure. This arrangement would allow the
centralizer on the proximal portion of the BHA to be positioned in
closer proximity to the bi-center reamer on the distal portion of
the BHA, thereby assuring less lateral movement of the bi-center
reamer as it rotates. The dotted reamer cutter body 41 of FIGS. 1
and 3 shows the cutting path of the eccentrically located cutters
as they move around the lip 53 of the pilot hole 50 as it is cut.
Finally, these same features may be applied to the embodiment shown
in FIGS. 3 and 4 without diminishing the substance or intent of
this disclosure. FIG. 4 shows a bi-center PDC reamer attachable on
the distal portion of the BHA. This assembly would be connected to
a bit or bull-nose plug below (not shown) connected at threaded
surface 21 and would be connected to a centralizer which is
selectively engageable to centralize and stabilize the PDC reamer
as it opens the hole from the pass through diameter to the desired
well bore diameter without unduly deviating from the center of the
well bore desired path. Reamer body 22 would have a PDC supporting
wing 25, which is populated by a number of PDC cutter elements 26,
all in a manner well known in this art.
[0020] As one may readily appreciate from disclosure of FIGS. 1, 3
and 4, the present embodiment stabilizes the bi-center reamer both
from above and below the lateral forces that tend to move the
bi-center reamer from the well bore wall, thereby permitting a
straighter, cleaner well bore.
[0021] The foregoing description has been directed to particular
embodiments of the invention in accordance with the requirements of
the statutes and for purposes of illustration and explanation of
the manufacture and use. It will be apparent to those skilled in
the art that many modifications and changes in the procedures set
forth will be possible without departing from the scope and spirit
of the invention. It is the applicant's intention to encompass all
such modifications and variations.
* * * * *