Note: Descriptions are shown in the official language in which they were submitted.
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SLICKLINE OR WIRELINE RUN HYDRAULIC MOTOR DRIVEN MILL
Inventors: Mary L. Laird; Robbie B. Colbert and David W. Coleman
FIELD OF THE INVENTION
[0001] The field of this invention is mills and more specifically those
that
are rotatably driven by a bottom hole assembly suspended from the surface
with a cable or wireline while a motor in the assembly powers the mill using
fluid flow into the tubular and most specifically a washover mill with an
advancing feature in the bottom hole assembly (BHA) to advance the mill as
the milling progresses.
BACKGROUND OF THE INVENTION
[0002] Tubing cutters have been run into a subterranean location into
tubing that is to be cut on coiled tubing and/or tubular. The coiled tubing or
tubular has fluid pumped through it to power a downhole motor that is fluid
driven such as a progressing cavity pump. The rotation of the pump drives the
cutter after extending its blades. Some examples are USP 7,225,873 and
7,086,467. Coiled tubing units are frequently not at a well site and are very
expensive to deploy.
[0003] Older designs would cut tubing using explosive charges that are set
off with a dropped weight on a slickline such as illustrated in USP 5,992,289.
These tools did not rotate and the positioning of the explosives made the
circumferential cut. These designs had the obvious safety issues of dealing
with explosives. The extension reach of the explosion could damage the outer
string on the back side of the tubing being cut.
[0004] Rotating tubing cutters have been run in on wireline where power
was transmitted to an electric motor in the bottom hole assembly as
illustrated
in USP 7,370,703.
[0005] Other assemblies disclose the use of a tubing cutter but the focus
is
on how the blades are extended or how the cutter is anchored with no details
about the drive system other than stating that there is a driver and that the
traditional conveyances for cutters such as coiled tubing, wireline or
slickline
can be used. Some examples are USP 7,478,982 and 7,575,056.
[0006] Slickline has been used in conjunction with an anchor and tubular
cutter that is rotated by a motor having a battery as the power supply as
shown
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in USP 8,210,251. Tractors have been used with local power supply in the
form of a battery to advance a BHA to the desired location in a deviated
wellbore while at the same time avoiding slack or over-tensioning the
slickline
used to deliver the BHA as is described in USP 8,151.902.
[0007] There are many occasions where a coiled tubing unit or an E-line
rig is not available and a need to cut tubing or mill arises. Under those
circumstances it would be advantageous to use a slickline supported cutter.
Since a slickline cannot convey power and a self contained power supply in
the bottom hole assembly, such as a battery, may not have the output to get
the
job done or may not even fit in a confined location of a small wellbore, the
present invention provides an alternative to make the tubing cut or to advance
a mill as a fish is being milled. A fish is the stuck object in the wellbore.
A
washover mill goes around the exterior of the fish such as a packer to
undermine the slips so that the packer can be released and in general fall
further down in the hole or actually get fished out. A washover mill can be
fitted with a tool to grasp the released fish for retrieval. A slickline or
wireline
cannot push a mill forward as the milling progresses and thus the present
invention contemplates ways to deploy a fluid motor run on electric line or
slick line to advance the mill or to put a force on the mill against the fish
during milling. More specifically telescoping joints that are spring loaded
with
fluid pressure are contemplated as well as a tractor in conjunction with a
telescoping joint with the tractor powered by wireline or a local power source
such as an onboard battery.
[0008] The preferred deployments of the invention is in a well with
production tubing inside casing where the tubing is cut to be freed from a
production packer by allowing it to extend so that its slips and sealing
system
can retract or washover milling of a stuck fish. In the context of this
application, the reference to "tubing" is to tubular strings in a wellbore and
includes casing, production or injection tubing in casing or tubulars in other
environments that need to be cut. In the preferred mode the rig pumps provide
fluid under pressure around the bottom hole assembly that is supported in the
tubular to be cut in a sealed manner and retained against reaction torque from
the cutting or milling operation. The pumped fluid enters the bottom hole
assembly through a ported sub and goes to a fluid driven pump such a
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progressing cavity pump to operate the cutter or mill. With a telescoping
assembly to let a mill advance, the pressurized fluid can be used as a force
to
compress springs that are used to keep a force on the mill and against the
fish
as the milling progreses. Exhaust fluid from the pump goes out the tubing and
back to the surface through perforated holes in the tubing allowing access to
the annulus where the tubing inside the casing is being cut or a fish is being
milled out. Those skilled in the art will more readily appreciate other
aspects
of the invention from a review of the detailed description and the associated
drawings that appear below while recognizing that the full scope of the
invention is to be found in the appended claims.
SUMMARY OF THE INVENTION
[0009] A tubing cutter is run in with a bottom hole assembly that includes
a seal and support within the tubing to be cut. A ported sub allows
pressurized
fluid pumped from the surface to enter the bottom hole assembly above the
sealed support location and to be directed to set an anchor and to a fluid
driven
motor such as a progressive cavity motor that is in turn connected to the
tubing
cutter at the rotor of the progressive cavity motor. The rotation of the
cutter
with its blades extended cuts the tubular as the fluid exiting the stator goes
to
the lower end of the tubing being cut and can return to the surface through an
annulus around the tubing to be cut. Other configurations such as cutting
casing or cutting casing through tubing as well as milling are also
envisioned.
Milling a fish such as with an overshot mill or another type of mill can be
accomplished with a telescoping assembly that has a bias against the mill
using springs, for example, where the springs are compressed with the
circulating pressurized fluid.
[0009a] Accordingly, in one aspect there is provided a method of operating
a
tool in a borehole leading to a subterranean location, comprising: delivering
the
tool to a first subterranean location at least in part on a cable; pumping
fluid into
the borehole to pressurize at least a portion of the borehole; using said
pressure to
operate said tool; and moving all of said tool to an axially spaced second
subterranean location while using said pressure to operate said tool.
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10009b1 According to another aspect there is provided a method of operating
a
tool in a borehole leading to a subterranean location, comprising: delivering
the
tool to the subterranean location at least in part on a cable; pumping fluid
into the
borehole to pressurize at least a portion of the borehole; using said pressure
to
operate said tool; moving said tool axially while using said pressure to
operate
said tool; and including a telescoping joint in a bottom hole assembly that
includes
said tool for said moving said tool axially.
[0009c] According to yet another aspect there is provided a method of
operating a tool in a borehole leading to a subterranean location, comprising:
delivering the tool to the subterranean location at least in part on a cable;
pumping
fluid into the borehole to pressurize at least a portion of the borehole;
using said
pressure to operate said tool; moving said tool axially while using said
pressure to
operate said tool; and using a mill as said tool for release of a fish at the
subterranean location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS, la-lb show the arrangement of a bottom hole assembly with
the tubing to be cut omitted for clarity;
[0011] FIG. 2 is a run in position of the preferred embodiment using a
washover mill;
[0012] FIG. 3 is the view of FIG. 2 with the mill landed on the fish;
[0013] FIG. 4 is the view of FIG. 3 during milling;
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[0014] FIG. 5 is an alternative embodiment to the view in FIG. 2 using a
tractor to hold weight on the mill and advance the mill as the milling
progresses.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] In one embodiment, the cutter assembly 10 is preferably
positioned
in a tubular string 12 that is disposed in a surrounding string such as casing
14
shown in part in FIG. la. A slickline 16 or alternatively a wireline, if
available
at the surface, supports the illustrated equipment down to the cutter 18 shown
in FIG. la with cutting blades 20 extended into the cutting position. The
slickline 16 supports an optional accelerator 22 for use in shallow depth
applications. Other familiar components when running slickline are employed
in the assembly 10 such as a fishing neck 24 and a jar tool such as 26. The
jar
tool 26 allows jarring to get unstuck while the fishing neck 24 allows the
assembly to be fished out if the jar tool 26 does not help it break loose. A
ported sub 28 has ports 30 that preferably stay open.
[0016] The equipment shown below the ported sub 28 is schematically
illustrated to perform a sealing function in string 12 so that fluid pumped
from
the surface will go into ports 30 and for securing the bottom hole assembly
against reaction torque from the cutting operation as the blades 20 are
rotated.
The anchor tool 32 has slips 34 driven along ramps 36 to bite the inside of
the
string 12 for support of the weight of the assembly 10 and to retain the
assembly 10 against rotation. A seal 38 is radially extendable in a variety of
ways. It can be made of a swelling material that reacts to well fluids or
added
fluids to swell and seal. It can be set against the inner wall of the string
12 by
longitudinal compression that is initiated mechanically such as when a
slickline 16 is in use or it can be actuated electrically using a setting tool
powered by power delivered through a wireline, when available. If the string
12 has a landing nipple that has a seal bore, on the other hand, the seal 38
can
just be advanced into the seal bore to get a seal. The no-go that is typically
provided in a landing nipple can be configured not only for weight support but
also for a rotational lock of the assembly 10. In those cases with latching
into a
landing nipple the anchor 32 would not be used as dogs going into a profile
provide weight support and a rotational lock.
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[0017] One or more pipe sections 40 can be provided for proper spacing
of
the blades 20 when working off a landing nipple. When using an anchor 32
that can be deployed as needed, the pipe sections 40 can be eliminated. A
downhole motor 42, preferably a progressive cavity Moineau pump is used
with a stationary stator 44 and a rotor 46 operatively connected to the tubing
cutter 18. Arrows 48 represent pumped fluid from the surface going down the
string 12 and entering the ports 30. From there the flow continues within the
assembly 10 to the stator 44 which sets the rotor 46 turning. The fluid is
exhausted from the stator 46 and follows the path of arrows 50, 52 and 54 to
get back to the surface through the annulus 58 between strings 12 and 14.
[0018] When used in a cased hole to cut casing the exhaust fluid from
the
motor 42 can be directed further downhole such as into a formation, although
in some application this may not be desirable. With larger sizes there can
also
be issues of the weight capacity of the slickline to support the assembly 10.
The preferred application is in cutting production or injection tubing such as
in
applications to sever a packer body to allow it to be released so that it can
be
removed with the tubing being severed. The anchor and seal 32 and 38 can be
configured for multiple deployments at different locations in a single trip so
that more than one cut of the tubular 12 can take place in one trip. Various
configurations of rotating cutters are envisioned that are responsive to
rotational input to operate. The tubing cutter 18 is a known product adapted
to
be used in the assembly 10.
[0019] In a broad sense a bottom hole assembly 10 can be run in on a
cable, whether slickline or a wireline, if available, for support in a tubular
to
be cut and the ability to divert flow pumped into the tubular to a downhole
motor to make the cut with a rotary bladed cutter or in the alternative with a
fluid jet or jets that can cut through the tubing either with or without body
rotation of the cutter. The motor 42 can drive a downhole pump that builds
pressure that is exhausted through jet nozzles in the cutter 18. Alternatively
the tubing 12 above the seal 38 can be raised to a high enough pressure to
operate cutting jets in the cutter 18. The support cable can be selectively
released to be removed from the wellbore after the tubular is cut. Depending
on the cutter configuration the tubing can be cut circumferentially for 360
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degrees to remove a part of it or an opening of a desired shape can also be
cut
into the tubular 12 depending on the cutter configuration.
[0020] In the preferred embodiment shown in FIG. 2, production tubing P
is run inside of casing C. A wireline or slickline 1 supports a fish neck
assembly 2 followed by a swivel 3. An optional accelerator 4 is next followed
by spang jars 5. The assembly thus far is made up of components known in the
art and assembled in an order that is also known in the art for functions that
are equally well known. For example, the swivel 3 prevents the line 1 from
getting wound up if for example during milling of the fish 15 the anchor 8
breaks loose and allows reaction torque to occur up the BHA. The induced
rotation will turn the swivel 3 but the line 1 will not turn. Spang jars 5 are
commonly used to get the BHA unstuck.
[0021] The FIG. 2 BHA uses a fluid circulation scheme that diverts fluid
pumped from the surface by the setting of a packer 7 that can be mechanically
or electrically set, for example. Fluid from the surface is diverted into the
drain sub 6 which is basically a ported sub. The fluid path runs through the
mandrel of the packer 7 and the anchor 8 that is adjacent in the BHA. The
fluid path is closed for run in at rupture disc 9. Those skilled in the art
will
realize that other types of removable barriers or valves can be used without
departing from the invention. However, if a rupture disc 9 is used which
breaks into pieces when actuated with fluid pressure from above, then a screen
sub 17 is used to catch the pieces and prevent them from getting to the mud
motor 19 that has close clearances and is preferably a progressing cavity
style
pump.
[0022] Compensator 11 is a telescoping assembly preferably with a bias
toward the shoe or mill 21. The bias can be a stack of Belleville washers 23
that are collapsed with set down weight of the BHA in a more vertical hole or
that are compressed with pressure differential from flow passing through the
stack of Belleville washers 23. The compensator 11 pushes against the mud
motor 19 which is then followed by a vacuum operated debris cleanup tool 13
that uses the flow that entered the BHA at sub 6 where such flow is first used
to break the rupture disc 9 after having set the anchor 8 so that flow can
pass
through the mud motor 19 and compress the washers 23. Other types of
biasing devices can be used as well as just the back pressure created by
forcing
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fluid through the venturi nozzles in the debris cleanup tool 13. The debris
cleanup tool 13 is of a type well known in the art such as the VACS tool sold
by Baker Hughes Incorporated and discussed in USP 6,276,452. The mill 21 is
preferably a washover type mill that takes cuttings on the inside as it
descends
onto the fish 15 and in so doing breaks the fish 15 loose such as by milling
away slips or a sealing element for a packer, for example. The fish 15 can be
allowed to drop once broken loose or it can be retained by the mill with a
schematically illustrated grasping device 25 that can be a ratchet, or surface
texture or some device that penetrates the fish 15 during milling to avoid
dropping it into the well.
[0023] FIG. 3 is the same as FIG. 2 with the mill 21 now lowered onto
the
fish 15. The anchor 8 is not yet set and the rupture disc 9 is still intact.
The
compensator 11 is collapsed using the pressure of the circulating fluid which
collapses the Belleville washers 23 to provide a net force on the mill 21 and
to
extend the compensator 11 as the mill moves axially during milling of the fish
15.
[0024] FIG. 4 shows the onset of delivery of pressurized fluid into the
production tubing P using arrows 27 going into ported sub 6. Arrow 29 shows
flow going through the packer 7 and sets the anchor 8 before breaking the
rupture disc 9 at flow arrow 31. Flow continues via arrow 33 into the mud
motor 19 as indicated by arrow 35. The flow stream exits the debris catcher 13
as the eductor exit flow from the VACS tool through ports 37 where some of
the flow continues down toward the mill 21 as shown by arrow 39 and the rest
of the flow goes up the production tubing P to ports 43 as indicated by arrow
45. The flow continues up the annulus 47 to the surface. As the milling
progresses the mill 21 is biased by the Belleville washers 23 or some other
biasing device to continue to extend the compensator 11 and to keep weight on
the mill 21 as it is rotated by the mud motor 19. The compensator 11 further
extends the mill 21 as the fish 15 is milled free.
[0025] FIG. 5 is essentially the same as FIG. 4 with the difference
being
that the compensator 11 is still a telescoping joint but the weight is kept on
the
mill 21 as a tractor 49 allows the telescoping joint to extend as the mill 21
advances to keep a load on the mill 21 as it mills the fish 15. The tractor 49
can be placed in different locations with respect to the telescoping joint or
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compensator 11. Line 1 is preferably a wireline with power supplied to the
tractor 49 routed through the BHA or/and outside the BHA. For example the
power line can run into the BHA at item 6 and through the BHA to the screen
sub to the tractor 49. The tractor 49 is a design well known in the art such
as
shown in USP 7,143,843.
[0026] Those skilled in the art will appreciate that the present
invention
allows running in a BHA that includes a mud motor driver on slickline or
wireline and to perform a milling operation where the mill advances as the
milling progresses and where the BHA accommodates the axial travel of the
mill while allowing force to be applied to the mill using a compensation
system that comprises a telescoping assembly with a biasing feature that is
activated in various ways. One way is using a tractor and another is using
mechanical or fluid force. Belleville washers can be compressed as the
telescoping assembly has its length reduced prior to the onset of milling. As
the milling progresses the compensating joint extends under the force of the
washers to allow the mill to progress under a force delivered by the washers.
The mill can be any style although a washover type with a retention feature
for
the fish is preferred. Depending on the mill style the circulation pattern or
even the use of a debris catcher can be altered to take into account the flow
path for the debris and how to best capture it either downhole or/and at the
surface. Alternatively the fish can be allowed to fall or be pushed further in
a
wellbore once milled loose. The tractor can have wheels or tracks and can be
on either end of the compensating assembly or telescoping joint. Debris
collection devices can be optionally used and can be of a variety of known
styles. The rupture disc 9 can be an opening that selectively opens and closes
so that the BHA can mill at more than a single location in a single trip.
Stopping fluid flow allows the BHA to release the anchor 8 so that the BHA
can be allowed to advance or be picked up for actuation at another location in
a wellbore or a lateral in the same trip. The selectively opened valve that
can
replace the rupture disc can be pressure responsive to open at a predetermined
pressure and otherwise close to permit another setting of the packer in a
different location. Various steering tools can also be used to aid in arriving
at
the proper location or locations.
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[0027] A fluid powered vibration tool 51 can be associated with the mill
21 to either grab the fish 15 to try to break it loose with vibration either
when
not milling or during milling.
[0028] The above description is illustrative of the preferred embodiment
and many modifications may be made by those skilled in the art without
departing from the invention whose scope is to be determined from the literal
and equivalent scope of the claims below.
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