U.S. patent application number 09/451422 was filed with the patent office on 2002-05-09 for reverse circulation junk basket.
Invention is credited to MAPLES, WALTER.
Application Number | 20020053428 09/451422 |
Document ID | / |
Family ID | 23792136 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020053428 |
Kind Code |
A1 |
MAPLES, WALTER |
May 9, 2002 |
REVERSE CIRCULATION JUNK BASKET
Abstract
An apparatus and method for capturing debris and metal cuttings
downhole in a wellbore. Fluid is reverse circulated through a
tubing positioned in the wellbore. An aperture opens to a larger
space within the tubing interior and creates a pressure drop which
separates the debris from the fluid. The debris is separated from
the fluid and is collected by an interior space within the tubing.
The tubing can be retrieved from the wellbore so that the debris is
separated from the interior space.
Inventors: |
MAPLES, WALTER; (SEALY,
TX) |
Correspondence
Address: |
ALAN J ATKINSON
P O BOX 270161
HOUSTON
TX
772770161
|
Family ID: |
23792136 |
Appl. No.: |
09/451422 |
Filed: |
November 30, 1999 |
Current U.S.
Class: |
166/99 ; 166/169;
166/311 |
Current CPC
Class: |
E21B 27/00 20130101 |
Class at
Publication: |
166/99 ; 166/169;
166/311 |
International
Class: |
E21B 031/08 |
Claims
What is claimed is:
1. An apparatus for capturing debris downhole in a wellbore when
fluid is reverse circulated through the wellbore and through a
hollow tubular positioned in the wellbore, comprising: a hollow
basket housing attached to said tubular; a basket member positioned
within said basket housing to define an interior volume between
said basket housing and said basket member for capturing the
debris; and an aperture in said basket member for permitting
reverse circulated flow of the fluid and debris therethrough,
wherein said aperture has a dimension smaller than an interior
dimension of the hollow tubular to generate a pressure drop
proximate to said basket member to facilitate separation of the
debris from the fluid.
2. An apparatus as recited in claim 1, wherein said basket housing
is detachable from the tubular to permit removal of the debris from
said interior volume.
3. An apparatus as recited in claim 1, wherein said basket member
is substantially cylindrical.
4. An apparatus as recited in claim 1, wherein said basket member
further comprises a sloped surface proximate to said aperture for
guiding fluid and debris through said aperture.
5. An apparatus as recited in claim 1, wherein said interior volume
is substantially toroidal with a closed end and an open end for
permitting entry of the debris into said interior volume.
6. An apparatus for capturing debris downhole in a wellbore when
fluid is reverse circulated through the wellbore, comprising: a
hollow tubular operable from the wellbore surface; a cutter head;
and a basket attached between said cutter head and said tubular,
wherein said basket comprises an exterior housing and an interior
member having an aperture for permitting flow of the fluid and
debris therethrough, and wherein said interior member and said
exterior housing form an interior volume for capturing the debris
as the fluid and debris are reverse circulated through said
aperture.
7. An apparatus as recited in claim 6, wherein said basket is
detachable from said tubular to facilitate removal of the debris
from said basket interior volume.
8. An apparatus as recited in claim 6, wherein said basket is
detachable from said cutter head to facilitate removal of the
debris from said basket interior volume.
9. An apparatus as recited in claim 6, wherein said interior member
is substantially cylindrical.
10. An apparatus as recited in claim 6, wherein said interior
member further comprises a sloped surface proximate to said
aperture for guiding fluid and the debris through said
aperture.
11. An apparatus as recited in claim 6, wherein said interior
member further comprises a ring having a threadform for detachable
engagement with said exterior housing.
12. A method for capturing debris downhole in a wellbore,
comprising the steps of: attaching a basket housing to a tubular to
define an interior volume within said tubular, wherein said basket
housing includes an aperture for permitting fluid flow
therethrough; positioning said tubular and basket housing downhole
in a wellbore; reverse circulating fluid to move the debris through
said aperture; and separating the debris from the fluid as the
debris and fluid passes through said aperture so that the debris is
captured within said basket housing interior volume.
13. A method as recited in claim 12, wherein said basket housing is
positioned at a selected location within the wellbore.
14. A method as recited in claim 12, further comprising the steps
of withdrawing said basket housing from the wellbore and of
removing the debris from said basket housing interior.
15. A method as recited in claim 12, further comprising the steps
of operating a mill to generate metal cuttings within the wellbore
and of capturing the metal cuttings within said basket housing
interior volume.
16. A method as recited in claim 12, further controlling the
flowrate of the circulating fluid to control the density of debris
captured within said basket housing interior volume.
17. A method as recited in claim 12, further comprising the step of
selecting the aperture dimension to control the fluid pressure drop
though said aperture as the debris and fluid flows
therethrough.
18. A method as recited in claim 12, further comprising the step of
selecting the aperture configuration to direct the debris toward
said basket housing interior volume.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to completion and repair
operations downhole in wellbores. More particularly, the invention
relates to an improved apparatus and method for capturing metal
debris and metal cuttings downhole in the wellbore.
[0002] Metal debris known as "junk" and metal cuttings and other
impurities are generated during wellbore completion and repair
operations. To create a window in the side wall of wellbore casing,
rotating mills are directed by a whipstock or similar device
against the casing interior wall. The rotating mills generate metal
cuttings heavier than the circulating fluid. Other types of
rotating mills remove packers and broken equipment from a wellbore
and clear obstructions from the wellbore. Metal cuttings from such
operations restrict wellbore production and encumber tool movement
through the wellbore.
[0003] "Junk baskets" operate with mills to capture debris and
metal cuttings during wellbore completions and milling operations.
Junk baskets are typically positioned on the drill stem exterior
surface as shown in U.S. Pat. No. 3,814,180 to Oliver (1974), which
disclosed a junk basket surrounding the tubular above a drilling
bit. U.S. Pat. No. 3,907,047 to Thompson et al. (1975) disclosed a
junk basket attached to a rotary drill bit which included an
annular cup. U.S. Pat. No. 4,111,262 to Duncan (1978) disclosed a
flexible junk boot clamped to the drill string exterior. U.S. Pat.
No. 4,217,966 to Garrett (1980) disclosed a metal cup spindled on a
drill bit pin so that the cup was automatically dumped each time
that the drill bit was removed from the stem. Additionally, U.S.
Pat. No. 4,390,064 to Enen et al. (1983) disclosed a releasable
junk basket attachable to the drilling string exterior
[0004] Certain junk baskets operate movable sleeves to collect
debris within a chamber. U.S. Pat. No. 5,135,050 to Tailby (1992)
disclosed a piston-like sleeve for use in horizontal wells which
was releasable to open ports for collecting a quantity of debris in
a chamber. Other junk baskets use magnets to attract and capture
metal fragments and cuttings. U.S. Pat. No. 4,059,155 to Greer
(1977) disclosed a magnet assembly in a longitudinally extending
passageway for capturing metal fragments. U.S. Pat. No. 5,944,100
to Hipp (1999) disclosed magnets attached to a tool body and
flexible fingers or brushes to move the debris from the magnets
toward a storage area.
[0005] Although most junk baskets are located exterior of the
tubular, U.S. Pat. No. 4,276,931 to Murray (1979) disclosed a junk
retaining means located within a tubular body. "Catchers" having
pivoted fingers were located above the milling teeth for capturing
metal debris. A reduced fluid pressure for drawing junk into a
chamber was created by activating inwardly extending fluid jets.
The jets were supported by a jet housing and were activated by a
pressure responsive activating means to capture junk within the
wellbore.
[0006] The proliferation of multilateral wells and complex wellbore
completion systems increases the need for milling operations in
wellbores. Increasingly close tolerances in valves and well control
equipment requires tight control over debris in the wellbores.
Additionally, conventional debris capture systems do not always
provide for selective fluid pressure control within a selected
wellbore location. Accordingly, a need exists for an improved
method and apparatus for capturing metal cuttings and other debris
downhole in a wellbore.
SUMMARY OF THE INVENTION
[0007] The present invention provides an apparatus and method for
capturing debris downhole in a wellbore when fluid is reverse
circulated through the wellbore. The apparatus comprises a hollow
basket housing attached to said tubular, a basket member positioned
within the basket housing to define an interior volume between the
basket housing and the basket member for capturing the debris, and
an aperture in the basket member for permitting reverse circulated
flow of the fluid and debris therethrough, wherein the aperture has
a dimension smaller than an interior dimension of the hollow
tubular to generate a pressure drop proximate to the basket member
to facilitate separation of the debris from the fluid.
[0008] In another embodiment of the invention, the apparatus
comprises a hollow tubular operable from the wellbore surface, a
cutter head, and a basket attached between the cutter head and the
tubular, wherein the basket comprises an exterior housing and an
interior member having an aperture for permitting flow of the fluid
and debris therethrough, and wherein the interior member and the
exterior housing form an interior volume for capturing the debris
as the fluid and debris are reverse circulated through the
aperture.
[0009] The method of the invention comprises the steps of attaching
a basket housing to a tubular to define an interior volume within
the tubular, wherein the basket housing includes an aperture for
permitting fluid flow therethrough, of positioning the tubular and
basket housing downhole in a wellbore, of reverse circulating fluid
to move the debris through the aperture, and of separating the
debris from the fluid as the debris and fluid passes through the
aperture so that the debris is captured within the basket housing
interior volume.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 illustrates an elevation view of an aperture in a
basket housing having an interior volume for capturing debris.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The invention provides an apparatus and method for capturing
debris downhole in a wellbore. The invention is particularly suited
for capturing metal filings generated during milling
operations.
[0012] FIG. 1 illustrates one embodiment of the invention wherein
tubular 10 formed with one or more sections is positioned within
wellbore 12. Basket 14 is attached to tubular 10 and generally
comprises basket housing 16 and basket member 18. Basket housing 16
has threadforms 20 and 22 for integral connection to tubular 10.
Basket housing 16 is formed with lower section 24 and upper section
26 connected with threadform 28. The interior wall of basket
housing 16 is cylindrical with a diameter substantially similar to
the interior diameter of tubular 10 in a preferred embodiment of
the invention. However, the shape, configuration and dimensions of
tubular 10 and of basket housing 16 can be shaped in different ways
to accomplish different design criteria, however basket housing 16
is hollow to permit the passage of fluid and of debris
therethrough..
[0013] An interior member or basket member 30 is attached to basket
housing 16 for the purpose of constricting fluid flow through
aperture 32 and for the purpose of forming interior volume 34. As
shown in FIG. 1, collar 36 is retained between surfaces 38 and 40
on lower section 24 and on upper section 26 respectively. Collar 36
has aperture 32 therethrough and is attached with threadform 42 to
sleeve 44. The exterior surface of sleeve 44 and the interior wall
of upper section 26 define a toroidal shaped space identified as
interior volume 34. Interior volume 34 has closed end 46 and open
end 48. Although interior volume 34 is formed as a toroid, the
configuration, shape, orientation and relative size of such
component can be varied to accomplish different design
objectives.
[0014] As shown in FIG. 1, mill 50 can be attached to threadform 22
to generate metal cuttings in wellbore 12. If tubular 10 is
rotatable from the surface of wellbore 12, mill 50 will not require
additional drive components.
[0015] Reverse circulation of fluid 52 in the direction shown will
transport debris such as junk or metal cuttings upwardly through
aperture 32. Sloped surface 54 can direct fluid 52 and the metal
cuttings toward aperture 32. As fluid 52 and the transported metal
cuttings travels through aperture 32 and exits through sleeve 44
into the interior of upper section 26, the pressure of fluid 52 is
reduced and the flow rate is correspondingly decreased. At such
location the transported metal cuttings separate from fluid 52 and
fall by gravity into interior volume 34. Fluid 52 moves upwardly
from the captured metal cuttings as fluid 52 is circulated through
tubular 10.
[0016] The invention is particularly suitable for the purposes of
washing pipe and tubing connections, and can be run to mill over
junk or through packers to prevent mill cuttings from falling
downwardly and being re-milled. By effectively capturing the metal
cuttings, the useful life of a mill shoe such as mill 50 will be
extended, therefore reducing the number of trips necessary to
replace mill 50.
[0017] The invention is also useful if the wellbore 12 is losing
fluid downhole because fluid 52 can be reverse circulated with low
pressure. As the metal cuttings tend to fall downwardly through
gravity, the metal cuttings are captured within interior volume 34
and do not reach mill 50.
[0018] The invention can be used with a hydro-static baller or mud
pump for light milling operations or to retrieve small pieces of
debris or junk that would otherwise flow through a drain sub or
flapper valve. The invention can be used to mill up loose debris
and bridge plugs and can be run with a drill bit or mill. The
invention is particularly suitable with a whipstock in milling
operations which form a window in exterior casing pipe set in
wellbore 12.
[0019] Although the invention has been described in terms of
certain preferred embodiments, it will become apparent to those of
ordinary skill in the art that modifications and improvements can
be made to the inventive concepts herein without departing from the
scope of the invention. The embodiments shown herein are merely
illustrative of the inventive concepts and should not be
interpreted as limiting the scope of the invention.
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