U.S. patent application number 12/905666 was filed with the patent office on 2011-04-21 for embedded multi-string well head shear.
This patent application is currently assigned to INTERMOOR, INC.. Invention is credited to Charles Brent Boyce, Matthew Jake Ormond, Gordon Robert Wilde.
Application Number | 20110088911 12/905666 |
Document ID | / |
Family ID | 43876592 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110088911 |
Kind Code |
A1 |
Boyce; Charles Brent ; et
al. |
April 21, 2011 |
EMBEDDED MULTI-STRING WELL HEAD SHEAR
Abstract
The present disclosure generally provides apparatus and methods
for removing a subsea well head. The apparatus may include an
embedded shear comprising a pile and a shear cutter integrated into
the pile. The shear cutter may be mounted within the pile near a
lower end thereof. The pile may include a well head conductor
receptacle adapted to receive a subsea well head, and the shear
cutter may include a shear blade that extends across the well head
conductor receptacle when activated. The method may include
providing a pile with a shear cutter integrated therein, lowering
the pile over the well head, pumping water out of the pile to drive
the pile into the seafloor to a desired cutting depth, activating
the shear cutter to cut off a portion of the well head, and pumping
water into the pile to drive the pile out of the seafloor.
Inventors: |
Boyce; Charles Brent; (New
Ulm, TX) ; Ormond; Matthew Jake; (Katy, TX) ;
Wilde; Gordon Robert; (Houston, TX) |
Assignee: |
INTERMOOR, INC.
Houston
TX
|
Family ID: |
43876592 |
Appl. No.: |
12/905666 |
Filed: |
October 15, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61252043 |
Oct 15, 2009 |
|
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Current U.S.
Class: |
166/361 ;
166/55 |
Current CPC
Class: |
E21B 29/007
20130101 |
Class at
Publication: |
166/361 ;
166/55 |
International
Class: |
E21B 29/12 20060101
E21B029/12; E21B 29/00 20060101 E21B029/00 |
Claims
1. An embedded shear comprising: a pile; and a shear cutter
integrated into the pile.
2. The embedded shear of claim 1 wherein: the pile is a suction
pile.
3. The embedded shear of claim 2 wherein: the pile further
comprises a pump interface.
4. The embedded shear of claim 1 wherein: the shear cutter is
hydraulically activated.
5. The embedded shear of claim 4 wherein: the shear cutter further
comprises hydraulic cylinders driven by external hydraulic
power.
6. The embedded shear of claim 5 wherein: the external hydraulic
power is supplied by one of a hydraulic umbilical, an accumulator
bottle or a remotely operated vehicle hot stab.
7. The embedded shear of claim 1 wherein: the pile further
comprises a well head conductor receptacle adapted to receive a
subsea well head.
8. The embedded shear of claim 7 wherein: the shear cutter further
comprises a shear blade that extends across the well head conductor
receptacle when activated.
9. The embedded shear of claim 1 wherein: the shear cutter is
mounted within the pile near a lower end thereof.
10. A method for removing a subsea well head comprising: providing
a pile with a shear cutter integrated therein; lowering the pile
over the well head; pumping water out of the pile to drive the pile
into the seafloor to a desired cutting depth; activating the shear
cutter to cut off a portion of the well head; and pumping water
into the pile to drive the pile out of the seafloor.
11. The method of claim 10 wherein: activating the shear cutter
comprises providing hydraulic power to hydraulic cylinders to drive
a shear blade.
12. The method of claim 10 further comprising: receiving the well
head within a well head conductor receptacle of the pile while
lowering the pile over the well head.
13. The method of claim 12 wherein: activating the shear cutter
comprises driving a shear blade across the well head conductor
receptacle to cut off the portion of the well head.
14. The method of claim 13 further comprising: retaining the cut
off portion of the well head within the well head conductor
receptacle.
15. The method of claim 14 further comprising: raising the pile
away from the seafloor while retaining the cut off portion of the
well head therein.
16. A method for removing a subsea well head comprising: providing
a pile with a shear cutter mounted internally near a lower end
thereof; lowering the pile over the well head; embedding the pile
into the seafloor to a desired cutting depth without excavating a
glory hole; activating the shear cutter to cut off a portion of the
well head; and removing the pile from the seafloor.
17. The method of claim 16 further comprising: raising the pile
away from the seafloor while retaining the cut off portion of the
well head therein.
18. The method of claim 16 wherein: embedding the pile into the
seafloor comprises pumping water out of the pile; and removing the
pile from the seafloor comprises pumping water into the pile.
19. The method of claim 16 further comprising: receiving the well
head within a well head conductor receptacle of the pile while
lowering the pile over the well head.
20. The method of claim 19 wherein: activating the shear cutter
comprises driving a shear blade across the well head conductor
receptacle to cut off the portion of the well head.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Application No. 61/252,043, filed
on Oct. 15, 2009 and entitled "Embedded Multi-String Well Head
Shear," which is incorporated herein by reference for all
purposes.
FIELD OF THE INVENTION
[0002] The present disclosure relates generally to the removal of
subsea well heads, and in particular, to the removal of subsea well
heads using an embedded multi-string well head shear.
BACKGROUND
[0003] Traditionally, subsea well heads have been removed by a
variety of different methods, including with the aid of explosives,
by using abrasive cutters internally, or by using shear tools
externally that require first excavating a so-called "glory hole"
deep enough to cut the well head about 15 feet or so below the mud
line.
[0004] The use of explosives subsea is becoming less favored due to
the negative environmental impact, especially as it relates to
marine life. Internal abrasive cutters have a low success rate for
multi-string conductors (i.e. concentric well casings with the
annular space between them grouted with cement) due to the overall
thickness of the steel pipe to be cut and the variable media (i.e.
steel to cement and back to steel).
[0005] Multi-string shear tools, such as massive hydraulic shears,
can externally sever an entire multi-string conductor in a single
cut once a glory hole is formed that allows the well head to be cut
below the mud line. However, excavating the glory hole requires an
extensive amount of soil removal since the sides of the pit must be
sloped back in order to maintain stability. Such an operation is
very time consuming and expensive, and it also has a negative
environmental impact.
SUMMARY OF THE DISCLOSURE
[0006] In one aspect, the present disclosure could generally
provide an embedded shear that comprises a pile and a shear cutter
integrated into the pile. The pile may be a suction pile. The pile
may further comprise a pump interface. The shear cutter may be
hydraulically actuated, and may further comprise hydraulic
cylinders driven by external hydraulic power. In various
embodiments, the external hydraulic power is supplied by one of a
hydraulic umbilical, an accumulator bottle or a remotely operated
vehicle hot stab. The pile may further comprise a well head
conductor receptacle adapted to receive a subsea well head. In an
embodiment, the shear cutter further comprises a shear blade that
extends across the well head conductor receptacle when activated.
The shear cutter may be mounted within the pile near a lower end
thereof.
[0007] In another aspect, the present disclosure could generally
provide a method for removing a subsea well head that comprises
providing a pile with a shear cutter integrated therein, lowering
the pile over the well head, pumping water out of the pile to drive
the pile into the seafloor to a desired cutting depth, activating
the shear cutter to cut off a portion of the well head, and pumping
water into the pile to drive the pile out of the seafloor. In an
embodiment, activating the shear cutter may comprise providing
hydraulic power to hydraulic cylinders to drive a shear blade. The
method may further comprise receiving the well head within a well
head conductor receptacle of the pile while lowering the pile over
the well head. In an embodiment, activating the shear cutter
comprises driving a shear blade across the well head conductor
receptacle to cut off the portion of the well head. The method may
further comprise retaining the cut off portion of the well head
within the well head conductor receptacle and/or raising the pile
away from the seafloor while retaining the cut off portion of the
well head therein.
[0008] In still another aspect, the present disclosure could
generally provide a method for removing a subsea well head that
comprises providing a pile with a shear cutter mounted internally
near a lower end thereof, lowering the pile over the well head,
embedding the pile into the seafloor to a desired cutting depth
without excavating a glory hole, activating the shear cutter to cut
off a portion of the well head, and removing the pile from the
seafloor. The method may further comprise raising the pile away
from the seafloor while retaining the cut off portion of the well
head therein. In some embodiments, embedding the pile into the
seafloor comprises pumping water out of the pile, and removing the
pile from the seafloor comprises pumping water into the pile. The
method may further comprise receiving the well head within a well
head conductor receptacle of the pile while lowering the pile over
the well head. In an embodiment, activating the shear cutter
comprises driving a shear blade across the well head conductor
receptacle to cut off the portion of the well head.
[0009] Other technical features may be readily apparent to one
skilled in the art from the following figures, descriptions and
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of this disclosure and its
features, reference is now made to the following description, taken
in conjunction with the accompanying drawings, in which:
[0011] FIG. 1A is schematic illustration of one embodiment of an
embedded shear comprising a shear cutter apparatus integrated into,
or mounted to, a suction pile;
[0012] FIG. 1B is a close vertical view from the bottom of the
embedded shear apparatus depicted in FIG. 1A;
[0013] FIGS. 2A-D is a storyboard illustration of one embodiment of
a method for removing a subsea well head.
DETAILED DESCRIPTION
[0014] Embodiments of the present disclosure generally provide
apparatus and methods for removing subsea well heads, such as
multi-string subsea well heads, by forcing an embedded shear
apparatus into the seafloor to the required cutting depth without
excavating a glory hole. In an embodiment, the embedded shear
comprises a shear cutter apparatus associated with a pile that may
be embedded into the seafloor by means of a suction system. The
suction pile may provide a foundation for the shear cutter, as well
as the motive force to embed the shear cutter to the required depth
to cut the well head.
[0015] FIG. 1A is a schematic elevation view of one embodiment of
an embedded shear 100 comprising a shear cutter apparatus 10
integrated into and/or mounted to a pile 20. In an embodiment, the
shear cutter 10 is located at a lower end of the pile 20 and
disposed internally thereof. The shear cutter 10 comprises a
hydraulic cylinder 14 and a shear blade 15. In an embodiment, the
pile 20 is a suction pile. The pile 20 may be generally cylindrical
in shape and comprises an outer wall 21, a top cap 22, a pump
interface 23, and a well head conductor receptacle 36. In an
embodiment, the well head conductor receptacle 36 starts at the
bottom of the pile and runs longitudinally within the interior of
the pile 20 to receive and position the well head within the pile
20.
[0016] FIG. 1B is a close vertical view from the bottom of the
embedded shear 100 of FIG. 1A. Protection grillage 37 is disposed
across an open lower end of the pile 20, and support beams 38 run
generally perpendicular to the protection grillage 37 to support
the shear cutter apparatus 10 within the pile 20. This view also
shows the relative positions of the hydraulic cylinders 14, the
shear blade 15, and the well head conductor receptacle 36.
[0017] FIGS. 2A-D depict a storyboard of one embodiment of a method
for removing a subsea well head 40 using the embedded shear 100 of
FIGS. 1A and 1B. As depicted in FIG. 2A, the embedded shear 100 is
positioned over a well head 40 extending above the seafloor 50 such
that the well head 40 is aligned with the well head conductor
receptacle 36 of the pile 20.
[0018] As the embedded shear 100 is lowered to receive the well
head 40 into the well head conductor receptacle 36, the pile 20
embeds itself into the seafloor 50 as shown in FIG. 2B. In most
cases, this initial embedded depth is not sufficient for cutting
the well head 40, and therefore, the pile 20 may be further
embedded into the seafloor 50 to position the shear cutter 10 to a
satisfactory depth.
[0019] FIGS. 2B and 2C show the pile 20 being suction embedded into
the seafloor 50 to achieve a satisfactory depth for the shear
cutter 10. In particular, water is pumped out of suction pile 20
through pump interface 23 creating a pressure differential that
drives the suction pile 20 further into the seafloor 50. Once a
satisfactory depth is achieved, the shear cutter 10 is activated
such that hydraulic cylinders 14 drive the shear blade 15 through
the well head 40, as shown in FIG. 2C. In an embodiment, external
hydraulic power may be provided to the cylinders 14 for activation.
Potential means of providing such hydraulic power are typically via
hydraulic umbilical, accumulator bottles or ROV (remotely operated
vehicle) hot stabs.
[0020] FIG. 2D depicts how the suction pile 20 is forced out of the
seafloor 50 by pumping water through the suction pump interface 23
into the suction pile 20. In particular, the pressure inside the
suction pile 20 is increased to a point where the pile 20 is driven
out of the seafloor 50. Because the shear blade 15 is not
retracted, the sheared portion 42 of the well head 40 is retained
within the well head conductor receptacle 36 of the suction pile 20
and thereby removed from the seafloor 50 with the embedded shear
100.
[0021] While this disclosure has described certain embodiments of
an embedded shear and generally associated methods, alterations,
and permutations of these embodiments and methods will be apparent
to those skilled in the art. Accordingly, the above description of
example embodiments does not define or constrain this disclosure.
Other changes, substitutions, and alterations are also possible
without departing from the spirit and scope of this disclosure and
the following claims.
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