Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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OW COI ' ' 8 N VER A RA ' ~
~ackarogrrd of t,~g ~venti~,
~'ie ~~ of l~he Invenyon
This invention relates to the freeing of stuck or
jarnryed tubulars or other objects dowrrirole and more
particularly, to a downhole coiled tubing recovery
apparatus and rnethod designed to utilize a resonant
frequency oscillator in combination with a specially
designed coiled tubing bail for directing coiled tubing
directly from a tubing reel through an injector Dead
and to and from the well responsive to raisirrg acrd
lowering of the oscillator and the tubing bail. F'reeiny
of the tubulars or objects is accomplished by typically
resonance vibration of the bail and coiled tubing by
operation of the oscillator.
~ Oil field tubulars such as well liners, casing,
tubing and drill pipe stuck in a well byre due to
Various downhole conditions have been one of the
principal sources of problems for oil operators and
have expanded .the business activity of fishing service
. ~ companies in this century. During this period of time.
many new and innovative tools and procedures have beer
developed to improve the success and efficiency of
fishing operations. Apparatus such as electric line
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free point tools, string shot assisted backoff,
downhole jarring tools, hydraulic-actuated tools of
various types and various other tools and equipment
have been developed for the purpose of freeing stuck or
jammed tubulars downhole in a well. Although use of
this equipment has become more efficient with time, the
escalation in cost of drilling and workover operations
has resulted in a proliferation of stuck pipe, liners,
casing and the like downhole, frequently leading to
well abandonment as the most expedient resolution of
the problem.
The use of vibration and resonant vibration in
particular, as a means of freeing stuck tubulars from a
well bore has the potential to be immediately effective
and thus greatly and drastically reduce the cost
involved in tubular recovery operations. Resonance
occurs in vibration when the frequency of the
excitation force is equal to the natural frequency of
the system. When this happens, the amplitude (or
stroke) of vibration will increase without bound and is
governed only by the degree of damping present in the
system.
A resonant vibrating system will store a
significant quantity of energy, much like a flywheel.
The ratio of the energy stored to the energy dissipated
per cycle is referred to as the systems "Q". A high
energy level allows the system to transfer energy to a
given load at an increased rate, much like an increase
in voltage will allow a flashlight to burn brighter
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with a given bulb. Only resonant systems will achieve
this energy buildup and exhibit the corresponding
efficient energy transmission characteristics which
assure large energy delivery and corresponding force
application to a stuck region of pipe.
At resonant conditions, a string of pipe will
transmit power over its length to a load at the
opposite end with the only loss being that necessary to
overcome resistance in the form of damping or friction.
In effect, power is transmitted in the same manner as
the drilling process transmits rotary power to a bit,
the difference being that the motion is axial
translation instead of rotation. The load accepts the
transmitted power as a large force acting through a
small distance. Resonant vibration of pipe can deliver
substantially higher sustained energy levels to a stuck
tubular than any conventional method, including
jarring. This achievement is due to the elimination of
the need to accelerate or physically move the mass of
the pipe string. Under resonant conditions, the power
is applied to a vibrating string of pipe in phase with
the natural movement of the pipe string.
When an elastic body is subjected to axial strain,
as in the stretching of a length of pipe, the diameter
of the body will contract. Similarly, when the length
of pipe is compressed, its diameter will expand. Since
a length of pipe undergoing vibration experiences
alternate tensile and compressive forces as waves along
the longitudinal axis (and therefore longitudinal
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strains), the pipe diameter will expand and contract in
unison with the applied tensile and compressive waves.
This means that for alternate moments during a
vibration cycle the pipe may actually be physically
free of its bond.
The term "fluidization" is used to describe the
action of granular particles when excited by a
vibrational source of proper frequency. Under this
condition, granular material is transformed into a
fluidic state that offers little resistance to movement
of body through the media. In effect, it takes some of
the characteristics and properties of a liquid.
Accordingly, skin friction, that force that confines a
stuck tubular, is reduced to a fraction of its normal
value due to the effect of vibration because of
alternate tensile and compressive forces applied to a
pipe and to the fluidization of granular particles
packed around the pipe.
Another factor in reducing stuck tubulars downhole
is acceleration, wherein a suitable vibrational stroke
may need to be only about an inch in order to produce
good acceleration for friction reduction and
fluidization. Accordingly, the vibrational energy
received at the stuck area works to effect the release
of a stuck member through the application of large
percussive forces, fluidization of granular material,
dilation and contraction of the pipe body and a
reduction of well bore friction or hole drag.
DPSCrigtiorL~f the Prior Art
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Resonant vibration systems for use in oilfield
tubular extraction applications consist of three basic
components: a mechanical oscillator with a suspension
device for isolating the rig or Support structure, a
work string for transmitting vibrational energy, and
the stuck tubular or fish to be recovered. The
oscillator generates an axial sinusoidal force that can
be tuned to a given frequency within a specified
operating range. The force generated by the oscillator
acts on the work string ~to create axial vibration of
the string. When tuned to a resonant frequency of the
system, energy developed at the oscillator is
efficiently transmitted to the stuck member with the
only losses being those attributed to frictional
resistance. The effect of the system reactance is
completely eliminated because mass inductance is equal
to spring campacitance at the resonant frequency. The
total resonant system must be designed so that the
components act in concert with one another, thus
2p providing an efficient and effective extraction system.
In conventional coiled'tubing operations one of
the actions that is detrimental to the life of the
coiled tubing is that of continually working the pipe
to and from the tubing reel, back and forth over the
well entry gooseneck. This action induces bending yield
stress into the tubing, which results in accumulated
fatigue damage and can eventually lead to fatigue
failure of the tubing wall. Modern instrumentation
allows monitoring of the tubing bending action and the
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coil service company will monitor and record that
action so that the coil is not used beyond its useful
life.
The principal of resonant axial vibration of pipe
can be applied to coiled tubing without using the
gooseneck equipment. Additionally, it has been found
that the coiled tubing does not necessarily need to be
cut when used with the downhole coiled tubing recovery
apparatus of this invention, thus saving the cost of a
reel of tubing, as well as maintaining and enabling good
well control, along with the facility for circulating fluids
into and from the well.
Various pipe recovery techniques are well known in the
art. An early pipe recovery device is detailed in U.S.
Patent No. 2,340,959, dated February 8, 1944, to P.E. Harth.
The Harth device is characterized by a suitable electrical
or mechanical vibrator which is inserted into the pipe to be
removed, such that the vibrator may be activated to loosen
the pipe downhole in the well and enable removal of the
pipe. A well pipe vibrating apparatus is detailed in U.S.
Patent No. 2,641,927, dated June 16, 1953, to D. B. Grabel,
et al. The device includes a vibrating element and a motor-
powered drive which is inserted in a well pipe to be
loosened and removed, to effect vibration of the pipe and
subsequent extraction of the pipe from the well. U.S. Patent
No. 2,730,176, dated January 10, 1956, to W. K. J. Herbold,
details a means for loosening pipes in underground borings.
The apparatus includes a device arranged within a
paramagnetic cylindrical body including a drill, a rod
rotatably mounted within the body and a disc member secured
to one end of the drill rod, the disc member having a mass
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which is substantially equally distributed around the
axis
of the drill rod to define a surface of revolution. A
motor
is provided for rotating the drill rod and a magnetic
apparatus for forcing the disc member into physical contact
with the inner walls of the body and into rolling contact
with the inner surface of the pipe upon rotation of the
drill rod, to loosen the pipe downhole. U.S. Patent No.
2,972,380, dated February 21, 1961, to A. G. Bodine, Jr.,
details an acoustic method and apparatus for moving objects
held tightly within a surrounding medium. The device
includes a vibratory output member of an acoustic wave
generator attached to an acoustically-free portion of
the
stuck tubular. The method includes operating the generator
at a resonant frequency to establish a velocity node
adjacent to the stuck point and a velocity antinode at
the
coupling point adjacent to the generator, to loosen the
stuck member from the well. U.S. Patent No. 3,189,106,
dated
June 15, 1965, to A. G. Bodine, Jr., details a sonic pile
driver which utilizes a mechanical Oscillator and a pile
coupling device for coupling the oscillator body to a
pile
and applying vibrations of the pile to drive the pile
into
the ground. U.S. Patent No. 3,500,908, dated March 17,
1970,
to U. S. Barler, details apparatus and method for freeing
well pipe. The device includes a number of rotatable,
power-
driven eccentrics which are connected to an elongated
member
such as a drill pipe that is stuck in an oil well bore
hole
and to a resiliently-movable support suspended from the
traveling block of an oil derrick. When the power-driven
eccentrics are operated, the elongated member is subjected
to vertically-directed forces that free it from the stuck
position. U.S. Patent No. 9,429,793, dated February 7,
1984,
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to Albert G. Bodine, details a well servicing system
employing sonic energy transmitted down the pipe string.
The
sonic energy is generated by an orbiting mass oscillator
coupled to a central stem, to which the piston of a
cylinder-piston assembly is connected. The cylinder is
suspended from a suitable suspension means such as a
derrick, with the pipe string being suspended from the
piston in an in-line relationship. The fluid in the
cylinder affords compliant loading for the piston,
while the fluid provides sufficiently high pressure to
handle the load of the pipe string and any pulling
force thereon. The sonic energy is coupled to the pipe
string in the longitudinal vibration mode, which tends
to maintain this energy along the string. U.S. Patent
No. 4,574,888 dated March 11, 1986, to Wayne E. Vogen,
details a "Method and Apparatus For Removing Stuck
Portions of A Drill String". The lower end of an
elastic steel column is attached to the upper end of
the stuck element and the upper end of the column
extends above the top of the well and is attached to a
reaction mass lying vertically above, through an
accelerometer and vertically-mounted compression
springs in parallel with a vertically-mounted servo-
controlled, hydraulic cylinder-piston assembly.
vertical vibration is applied to the upper end of the
column to remove the stuck element from the well. A
"Device For Facilitating the Release of Stuck Drill
Collars" is detailed in U.S. Patent No. 4,576,229,
dated March 18, 1986, to Robert L. Brown. The device
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includes a first member mounted with the drill pipe
disposed in a first position and a second member
concentrically mounted with a drill collar or drill pipes
in a second position below the first position. Rotation
of the drill string from the surface causes a caroming
action and vibration in a specified operative position of
the device, which helps to tree stuck portions of the
drill pipe. U.S. Paten.t No. 4,788,467, dated November
29, 1988, to E.D. Plambeck details a downhole oil well
vibrating apparatus that uses a transducer assembly
spring chamber piston and spring to effect vibration of
downhole tubulers. U.8',. Patent No. 5,234,056, dated
August 10, 1993, to Albert G. Bodine, details a "Sonic
Method and Apparatus Fc~r Freeing A Stuck Drill String".
The device includes a mechanical oscillator employing
unbalanced rotors coupled to the top end of a drill
string stuck in a bore hole. Operation of the unbalanced
rotors at a selected frequency provides resonant
vibration of the drill string to effect reflected wave at
the stuck point, resulting in an increased cyclic force
at this point.
The prior art is well established regarding the
application of vibratian to stuck downhole tubulars of
the conventional type ;threaded pipe). There is no
suggestion, however, of any means or method for handling
continuous pipe such as coiled tubing, in a vibrational
or any other application. Thus, the present invention
provides an apparatus and method for working coiled
tubing in a stuck pipe or other downhole stuck equipment
situation, wherein the coil may be raised and lowered in
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the well bore by a support structure that includes a
lifting and lowering apparatus. Such movement of the
coil is accomplished with substantially no bending of the
coil string.
This invention also provides a new and improved
downhole coiled tubing recovery apparatus and method for
releasing and recovering coiled tubing and other objects
stuck or jammed downhole in a well.
The invention provides a new and improved downhole
coiled tubing recovery apparatus and method which
operates utilizing resonant vibration in combination with
a specially designed coiled tubing bail to facilitate the
release of stuck or januned coiled tubing from a well.
The invention provides a new and improved coiled
tubing recovery apparatus that may be applied to a
continuous length of coiled tubing without cutting the
tubing, and operated to vibrate the coiled tubing and
remove the coiled tubing and other objects from a stuck
or jammed position in t:he well.
The invention provides a new and improved downhole
coiled tubing recovery apparatus which is characterized
by specially designed coiled tubing bail adapted to
receive a length of coiled tubing from a reel and direct
the coiled tubing through an injector head into and from
the well, the coiled tubing bail being attached directly
to the rig or to an oscillator suspended from the rig for
selectively vibrating i~he coiled tubing and removing the
coiled tubing from a stuck or jammed condition in the
well.
This invention alao provides a downhole coiled
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tubing recovery apparatus which utlizes an oscillator for
attachment to a length of coiled tubing and applying a
resonant vibration directly to the coiled tubing for
removing the coiled tubing from a stuck or jammed
condition in a well.
This invention also provides a downhole coiled
tubing recovery apparatus and method, which apparatus is
characterized by an oscillator suspended from a rig or
other support structure: and a coiled tubing bail attached
to the oscillator for receiving a length of coiled tubing
extending from a coiled tubing reel and directing the
coiled tubing through an injector head into the well,
such that the oscillate>r can be operated to vibrate the
coiled tubing, typically at a resonant frequency, and
remove the coiled tubing from a stuck or jammed condition
in the well.
The invention provides a coiled tubing recovery
apparatus and method which is designed to vibrate jammed
or stuck coiled tubing and reduce the friction of tubing
insertion and extraction in a well.
Summary of the Invention
Accordingly, the 'nvention provides a new and
improved coiled tubing recovery apparatus and method,
which apparatus is characterized in a preferred
embodiment by specially designed coiled tubing bail
suspended directly from a rig structure of from an
oscillator that is furi:her suspended from the travelling
block or other supporting structural element of an oil
derrick or rig. The method of this invention includes
directing the coiled tubing from a reel through a set of
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rod clamps in the coiled tubing bail and through an
injector head, into the well bore. In the event of a
stuck or jammed condition of the coiled tubing in the
well bore, the coiled tubing bail can be lifted and/or
the oscillator can be lifted and operated to apply
resonant vibration through the coiled tubing bail and
coiled tubing to looser the coiled tubing in the well
hole.
The present invention provides a coiled tubing
recovery apparatus for freeing coiled tubing in a well,
comprising a vibrator ~;uspended above the well and a
coupler carried by said vibrator for connecting the
coiled tubing to said vibrator and vibrating the coiled
tubing responsive to operation of said vibrator.
The present invention also provides a coiled tubing
recovery apparatus for freeing coiled tubing extending
from a reel through an injector head into well, said
apparatus comprising a vibrator suspended above the well;
a coiled tubing bail having a connector plate positioned
adjacent to said vibrator; a pair of bail legs extending
from said connector plate in spaced-apart relationship
with respect to each other; a pair of tubing plates
spanning said bail leg:, said tubing plates spaced-apart
to receive the coiled tubing therebetween; a connector
connecting said vibrator and said connector plate of said
coiled tubing bail for suspending said coiled tubing bail
from said vibrator; and at least one clamp disposed
adjacent to said tubing plates of said coiled tubing bail
for receiving and selectively clamping the coiled tubing
in said coiled tubing bail.
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The present invention also provides a method for
freeing coiled tubing in a well having an injector head,
comprising suspending a vibrating apparatus over the well
and the injector head; attaching a coiled tubing bail to
the vibrating apparatus; providing a least one clamp in
the coiled tubing bail for selectively clamping the
coiled tubing in the coiled tubing bail; and extending
the coiled tubing from a coiled tubing reel through the
clamp, the coiled tubing bail and the injector head, into
the well and,operating the vibrating apparatus at a
resonant frequency to vibrate the coiled tubing hail and
the coiled tubing in the well at the resonant frequency.
In a further aspect, the present invention provides
a method for freeing coiled tubing in a well, comprising
suspending a coiled tubing bail over the well; attaching
the coiled tubing to the coiled tubing bail; and applying
an upward force to the coiled tubing bail for removing
the coiled tubing from the well.
In a still further aspect, the present invention
provides a method for freeing coiled tubing in a well,
comprising suspending a coiled tubing bail over the well,
said coiled tubing bail comprising a connector plate, a
pair of bail legs extending from the connector plate in
spaced-apart relationship with respect each other and a
pair of tubing plates spanning the bail legs with the
tubing plates spaced-apart to receive the coiled tubing
therebetween; attaching the coiled tubing to the coiled
tubing bail; and applying an upward force to the coiled
tubing bail for moving the coiled tubing from the well.
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Brief Description of the Drawings
The invention will be better understood by reference
to the accompanying drawings, wherein:
FIGURE 1 is a perspective view of a typical coiled
tubing oscillator and a bail element (rod clamps removed
for brevity) of the downhole coiled tubing recovery
apparatus of this invention, with a length of coiled
tubing extending througr. the bail and into an injector
head;
FIGURE 2 is a front. view of the coiled tubing
oscillator and bail illustrated in FIGURE 1;
20
30
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FIGURE 3 is a front view of an alternative
embodiment of the invention wherein a length of the
coiled tubing is attached directly to the oscillator:
FIGURE 4 is a front view of a preferred embodiment
of the coiled tubing bail element of the downhole
coiled tubing recovery apparatus of this invention;
FIGURE 5 is a side view of the coiled tubing bail
illustrated in FIGURE 4:
FIGURE 6 is a perspective view of the coiled
tubing bail illustrated in FIGURES 4 and 5; and
FIGURE 7 is a front view of a typical union for
connecting the length of coiled tubing to the
oscillator in the embodiment of the invention
illustrated in FIGURE 3.
nPscr~ption o~,the Preferred Embodiments
Referring initially to FIGURES 1, 2 and 4-6 of the
drawings, in a first preferred embodiment the coiled
tubing recovery apparatus of this invention is
generally illustrated by reference numeral 1. The
coiled tubing recovery apparatus 1 includes a coiled
tubing bail 2, more particularly illustrated in FIGURES
4-6, including a union connector 3 at the top end
thereof, having a connector opening 3a, fitted with
internal connector threads 3b (FIGURE 6). A connector
plate 9 joins a pair of vertically-oriented, parallel
bail legs 5 at the union connector 3 and the bottom
ends of the bail legs 5 are connected by means of a
pair of parallel tubing plates 6, joined by plate bolts
7, secured by nuts 8, as further illustrated in FIGURES
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4-6. In a most preferred embodiment, two sets of the
plate bolts 7 extend through the respective bail legs
5, while another set of the plate bolts 7 extend in
spaced-apart relationship with respect to each other
near the center of the tubing plate 6, for
accommodating the downhole segment 29 of a length of
coiled tubing 28, as illustrated in FIGURES 1 and 2.
As further illustrated in FIGURES 1 and 2, the
coiled tubing 28 is typically conventionally wound on a
tubing reel 32, and is directed through the parallel
bail legs 5, between the tubing plates 6 of the coiled
tubing bail 2 and through one or more clamps, such as
the conventional rod clamps 10, having clamp jaws 11,
connected by jaw bolts 12, as further illustrated in
FIGURE 2. Accordingly, it will be appreciated from a
consideration of FIGURES 1 and 2 that the coiled tubing
28 is characterized by a tubing reel segment 30, which
is wound on the tubing reel 32 and extends from the
tubing reel 32 to the coiled tubing bail 2, where a
downhole segment 29 of the coiled tubing 28 projects
through the rod clamps 10 and between the respective
tubing plates 6, through an injector head 14 that
usually serves to insert the coiled tubing 28 into a
well bore (not illustrated) and remove the coiled
tubing 28 from the well bore as desired, according to
the knowledge of those skilled in the art.
Referring again to FIGURES 1 and 2 of the
drawings, the coiled tubing bail 2 is typically
suspended from a conventional oscillator 22 at a union
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16, detailed in FIGURE 7. The union 16 is typically
characterized by a top coupler 17, having exterior top
coupler threads 18 that threadably engage the internal
coupler threads (not illustrated) shaped in the
oscillator 22. The bottom coupler threads 20 of the
bottom coupler 19 engage the connector opening threads
3b in the connector opening 3a of the union connector
3, as further illustrated in FIGURE 6. However, it will
be appreciated by those skilled in the art that the
coiled tubing bail 2 can be suspended from the
oscillator 22 in other ways, such as by direct threaded
attachment, slips and the like, as desired. The
conventional oscillator 22 is typically characterized
by an eccentric housing 23, which houses at least one
pair of eccentrics (not illustrated) that are connected
to the motor shafts 25 (FIGURE 2) of a pair of
eccentric drive motors 24. A spring housing 26 is
positioned above the eccentric housing 23 for enclosing
several springs (not illustrated) and isolating the
vibration from the eccentrics located in the eccentric
housing 23. The oscillator 22 is typically suspended
from the travelling block or other element of an oil
derrick or rig, (not illustrated), positioned over the
well. Alternatively, the coiled tubing bail 2 can be
attached directly to the travelling block or other
component of the oil derrick or rig by means of
threaded couplings, slips, or the like.
In operation according to the method of this
invention, the downhole segment 29 of the coiled tubing
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28 may be extended through the respective loosened
clamp jaws 11 of the rod clamps 10, and between the
parallel tubing plates 6, into the injector head 14, as
illustrated in FIGURE 1. When it is desired to extend
or insert the downhole segment 29 of the coiled tubing
28 into the well, the injector head 14 is released from
the downhole segment 29 and the coiled tubing bail 2 is
raised and lowered, as necessary. Alternatively, the
injector head 14 may be operated in conventional
fashion to feed the coiled tubing 28 into the well. As
the downhole segment 29 is fed into the well through
the injector head 14, the tubing reel segment 30 of the
coiled tubing 28 unwinds from the rotating tubing reel
32. It will be appreciated that during this procedure,
the clamp jaws 11 of the rod clamps 10 are sufficiently
slack by manipulation of the jaw bolts 12 to facilitate
easy sliding movement of the coiled tubing 28 through
the respective rod clamps 10 and between the tubing
plates 6 and the spaced-apart inside ones of the plate
bolts 7. Normal bottom hole operations utilizing the
coiled tubing 28 can be effected upon completion of the
insertion of the coiled tubing 28 into the well.
However, under circumstances where the coiled tubing 28
gets stuck or jammed in the well due to well bore cave-
in or other adverse downhole phenomena, retrieval of
the coiled tubing 28 from the well bore can be achieved
by operating the oscillator 22 to apply a vibration,
typically at resonant frequency, to the coiled tubing
bail 2 and the coiled tubing 28, attached to the coiled
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tubing bail 2, and release the coiled tubing 28 from
the stuck or jammed condition in the well. In the
course of applying a resonant frequency to the coiled
tubing 28, the oscillator 22 generates an axial
sinusoidal force that can be tuned to a specified
frequency within the operating range of the oscillator
22. The force generated by, the oscillator 22 acts on
the coiled tubing 28 to create axial vibration of the
downhole segment 29 of the coiled tubing 28. When tuned
to a resonant frequency of the system, energy developed
at the oscillator 22 is efficiently transmitted to the
stuck downhole segment 29 of the coiled tubing 28, with
the only losses being those attributed to frictional
resistance. The effect of the coiled tubing 28
reactance is completely eliminated, because mass
induction is equal to spring capacitance at the
resonant frequency. Other aspects of the oscillator 22
operation is the fluidization of the granular particles
downhole in the event that the cause of the stuck
downhole segment 29 of the coiled tubing 28 results
from a cave-in or silting of the hole or jamming of
downhole objects to create a mechanical wedging action
against the downhole segment 29 of the coiled tubing
28. When excited by a vibration from the oscillator 22,
the granular particles are transformed into a fluidic
state that offers little resistance to movement of the
coiled tubing 28 upwardly or downwardly. In effect, the
granular media takes on the characteristics and
properties of a liquid and facilitates extraction of
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the downhole segment 29 of the coiled tubing 28 by
elevating and/or lowering the coiled tubing 28 as
described above.
Referring now to FIGURE 3 of the drawings, in
another preferred embodiment of the invention the
tubing reel segment 30 of the coiled tubing 28 may be
cut and connected directly to the union 16 of the
oscillator 22 to eliminate the coiled tubing bail 2. In
this operation, the downhole segment 29 of the coiled
tubing 28 may first be extended directly through the
injector head 14 and conventionally, lowered into the
well directly from the tubing reel 32 through the
injector head 14, for commencement of downhole
operations utilizing the coiled tubing 28. Under
circumstances where the downhole segment 29 of the
coiled tubing 28 becomes stuck or jammed in the well,
the coiled tubing 28 is cut at a point above the
injector head 14 and the tubing reel segment 30
attached to the union 16 by techniques known to those
skilled in the art, and the oscillator 22 is then
operated as described above, to free the coiled tubing
28 downhole. When the coiled tubing 28 is free, the
upper end, or tubing reel segment 30 of the coiled
tubing 28 is disconnected from the union 16 and the
injector head 14 is reverse-operated to remove the
coiled tubing 28 from the well, as described above. .
Alternatively, the coiled tubing bail 2 can be attached
directly to the travelling block or other rig component
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as described above and the travelling block lifted Lo
free the coiled tubing 28 from the well.
It will be appreciated by those skilled iu the
that one of the advantages of the coiled tubine~
recovery apparatus and method of this inventlou is ~:l~e
facility for manipulating the coiled tubing, 2E3 direc:~9.y
. from the tubing reel 32 without the necessity of
cutting the coiled tubing 28 in the embodirnent~3
illustrated in FIGURES 1, 2 and 4-6.~ Another advanta~~e
is the elimination of tt~e conventional "gooseneck"
.. equipment, which tends to degrade the coiled tubing 28
through multiple bends over tl~e gooseneck as the coi3 eci
tubing 28 is inserted into and removed from five well bv,~
operation of the injector head 14.
~ While the preferred ecxibodici~ents of the invention
~~have been described above, it will be recognized and
understood that various modifications rnay be made in
the invention and tire appended claims are intended to
cover' all such modifications which may fall within tire
" ~ spirit and scope of the invention.
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