U.S. patent application number 12/484211 was filed with the patent office on 2009-12-17 for methodolgy and apparatus for programmable robotic rotary mill cutting of multiple nested tubulars.
Invention is credited to Mark Franklin Alley, Wesley Mark McAfee.
Application Number | 20090308605 12/484211 |
Document ID | / |
Family ID | 41413715 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090308605 |
Kind Code |
A1 |
McAfee; Wesley Mark ; et
al. |
December 17, 2009 |
Methodolgy and apparatus for programmable robotic rotary mill
cutting of multiple nested tubulars
Abstract
A methodology and apparatus for cutting shape(s) or profile(s)
through well tubular(s), or for completely circumferentially
severing a well through multiple tubulars, including all tubing,
pipe, casing, liners, cement, other material encountered in tubular
annuli. This rigless apparatus utilizes a computer-controlled,
downhole robotic three-axis rotary mill to effectively generate a
shape(s) or profile(s) through, or to completely sever in a 360
degree horizontal plane wells with multiple, nested strings of
tubulars. This is useful for well abandonment and decommissioning
where complete severance is necessitated and explosives are
prohibited, or in situations requiring a precise window or other
shape to be cut through a single tubular or plurality of
tubulars.
Inventors: |
McAfee; Wesley Mark;
(Montgomery, TX) ; Alley; Mark Franklin;
(Nashville, TN) |
Correspondence
Address: |
Wesley Mark McAfee
43 Brookgreen Circle North
Montgomery
TX
77356-8358
US
|
Family ID: |
41413715 |
Appl. No.: |
12/484211 |
Filed: |
June 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61131874 |
Jun 14, 2008 |
|
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|
Current U.S.
Class: |
166/255.1 ;
166/55.7; 166/55.8 |
Current CPC
Class: |
E21B 44/00 20130101;
E21B 29/005 20130101 |
Class at
Publication: |
166/255.1 ;
166/55.7; 166/55.8 |
International
Class: |
E21B 29/00 20060101
E21B029/00; E21B 43/112 20060101 E21B043/112; E21B 47/09 20060101
E21B047/09; E21B 47/00 20060101 E21B047/00; E21B 43/119 20060101
E21B043/119 |
Claims
1. An apparatus for cutting shape(s) or profile(s) through well
tubular(s), or for completely circumferentially severing a well
through multiple tubulars, including all tubing, pipe, casing,
liners, cement, other material encountered in tubular annuli and
formation rock, comprising: a computer-control equipped control
cabin; a motorized reel with umbilical cord and distance or feed
measurement counter, winch with cable, as required, enclosed
electrical and communication wire(s) and hydraulic hose(s); a
downhole assembly body; a computer-controlled profile generation
system for generating and coordinating control signals sent to a
three-axis, processor-controlled, downhole robotic rotary mill
which simultaneously, and optimally, using sensor feedback
adjustment, moves a powered rotary carbide milling cutter up and
down in a vertical plane along a Z-axis of a well bore inside the
downhole assembly and rotates in a 360 degree horizontal rotary
W-axis of the wellbore inside of the downhole assembly, a swing arm
with a rotary milling spindle that moves in a Y-axis arc from the
Y-axis body attached to the downhole assembly, and the simultaneous
movement of the Z-axis, W-axis, and Y-axis enabling cutting the
tubulars, cement, other annular material or formation rock in any
programmed shape(s) or window profile(s), including complete
horizontal circumferential severance of all tubulars and annular
material.
2. The apparatus according to claim 1, the downhole assembly is
deployable riglessly downhole into a wellbore with an umbilical
cord or cable from the surface.
3. The apparatus according to claim 1, the downhole assembly is
deployable downhole into a well bore with a work string from the
surface.
4. The apparatus according to claim 1, wherein the tubulars that
are to have shape(s) or profile(s) generated, or that are to be
completely severed, are of metal.
5. The apparatus according to claim 1, wherein the tubulars that
are to have shape(s) or profile(s) generated, or that are to be
completely severed, are of composite material.
6. The apparatus according to claim 1, wherein the downhole
assembly is adapted to be received into an innermost tubular with a
minimum inside diameter of 5.75 inches and received into an
innermost tubular with a maximum inside diameter of 19 inches.
7. The apparatus according to claim 1, wherein the well is an oil
well or a gas well, or a similar conductor or support structure
comprised of multiple, nested tubulars.
8. The apparatus according to claim 1, wherein the downhole
assembly is lockable inside of the well bore with either cylinders,
packers, or mechanical means and is capable of selectively locking
itself into the tubular from a command from the computer
processor.
9. The apparatus according to claim 2 has a quick-disconnect
connection umbilical cord or cable that can be disconnected by a
means controlled from the surface controls.
10. The apparatus according to claims 1, wherein the Z-axis
movement drive may be electrically or hydraulically driven, with a
ball screw, cylinder, or rack and pinion.
11. The apparatus, according to claim 1, wherein an inertia
reference system is utilized for sensory positional data.
12. The apparatus according to claim 10, wherein an encoder
supplies Z-axis electrical position data to the computer
processor.
13. The apparatus according to claim 10, wherein a load cell
measures Z-axis forces for adaptive feedback to the computer
processor.
14. The apparatus according to claim 8, wherein a W-axis motor is
driven either electrically or hydraulically and rotates a cylinder
inside the downhole assembly.
15. The apparatus according to claim 14, wherein an encoder
supplies W-axis electrical position data to the computer
processor.
16. The apparatus according to claim 14, wherein a load cell
measures W-axis forces for adaptive feedback to the computer
processor.
17. The apparatus according to claim 8,.wherein a Y-axis is
attached to the bottom of the W-axis.
18. The apparatus according to claim 17, wherein the W-axis body
houses a motor driven milling spindle swing arm that is pivot
mounted in the W-axis body.
19. The apparatus according to claim 18, wherein the milling
spindle swing arm motor may be housed in the pivoted milling
spindle swing arm or driven by a motor in the W-axis body supplying
power to the milling spindle swing arm through a swivel coupling,
such as a C.V. joint.
20. The apparatus according to claim 18, wherein the milling
spindle swing arm motor has an encoder for supplying RPM data to
the computer processor.
21. The apparatus according to claim 17, wherein the Y-axis body
has a hydraulic cylinder so arranged as to feed out the motor
driven spindle in an arc, thereby enabling cutting of the
tubular(s).
22. The apparatus according to claim 20, wherein the hydraulic
cylinder has been gun-drilled for an inductive positioning system
to supply electrical position data to the computer processor.
23. The apparatus according to claim 20, wherein the hydraulic
cylinder presses on a load cell to provide adaptive feedback to the
computer processor.
24. The apparatus according to clam 1, wherein the three-axis
robotic downhole rotary mill will completely sever through multiple
nested, non-concentric, cemented tubulars of any thickness that can
be machined with carbide, out to and through an outermost tubular
of 42-inch diameter, initiating the severance from the smallest
tubular in claim 6.
25. A method for downhole three-axis rotary milling utilizing a
downhole assembly that is 360-degree rotatable, with extendable,
pivotal, motor-driven, swing arm(s) with rotary milling cutter(s)
to generate shape(s) or profile(s) through well tubular(s), or to
completely circumferentially sever a well, with cutting and
severance beginning from the innermost tubular of the well and
including severance of all tubulars, including tubing, pipe, casing
and liners and also cement or other material in the annuli of said
tubulars, comprising the steps of: transporting to the well
abandonment site the downhole assembly, a computer control-equipped
operator cabin, a motorized reel with umbilical cord, winch with
cable, or work string, or, as required, enclosed electrical and
communication wire(s) and hydraulic hose(s) attached to the
downhole assembly; lowering an electronic or mechanical device into
the wellbore for the purpose of verifying drift and clearance for
the downhole assembly and subsequently retrieving this device after
it has provided data down to the depth where the downhole assembly
is to be locked in place and at which cutting or severance
operations will take place; lifting the downhole assembly by
on-site crane and inserting it, as well as attached umbilical cord
or cable, into the wellbore; monitoring a distance measurement
counter to ensure that as the downhole assembly is lowered into the
well it reaches the correct depth in the area at which cutting or
severance operations will take place; locking the downhole assembly
in place, by means of a packer or hydraulically or electrically
operated locking mechanism, thus maintaining the vertical position
of the downhole assembly inside the innermost tubular of the
installed multiple, nested casing; utilizing a programmable,
computerized central processing unit (CPU) from the control cabin
to communicate electronically to send and receive digital sensor
data from components of the downhole assembly and from a digital
inertial reference system, algorithmically engaging robotic axial
and milling actuation based upon received data, or, alternatively,
embedding a CPU in the downhole unit to send and receive digital
sensor data from components of the downhole assembly and an
inertial reference system, algorithmically engaging robotic axial
and milling actuation based upon received data; engaging robotic
axial and milling actuation specifically to include up and down
movement along the Z-axis in the downhole assembly; W-axis rotation
of the downhole assembly permitting 360 degree circumferential
horizontal rotation; Y-axis arc feed of the extendable, pivotal,
motor-driven, swing arm(s) with rotary milling cutter(s); rotation
of the milling spindle assembly measured in RPM; torque adjustment
due to torque encountered by the milling spindle swing arm
assembly; and other combinations of Z-axis, W-axis and Y-axis
adjustment that may be required to generate a specific shape or
profile of specific shape or location based on digital inertia or
encoder reference system data.
26. The method of claim 25, in order to achieve complete severance
of all tubulars, including tubing, pipe, casing and liners and also
cement or other material in the annuli of said tubulars, comprising
the steps of: rotating the downhole assembly in a 360-degree
horizontal plane on the W-axis and moving the Z-axis vertical
movement up or down, while feeding out along the Y-axis radially
and rotating the extendable, pivotal, motor-driven, swing arm(s)
with rotary milling cutter(s); increasing progressively the
circumference or extension of the cut; and utilizing combinations
of X-, Y-, and Z-axis movement of the downhole assembly and
extendable, pivotal, motor-driven, swing arm(s) with rotary milling
cutter(s) to generate optimal mill cuts, create proper space for
cutting and ensure sufficient extension of said arm(s), especially
initiating cuts at a lower point and moving upward along the
Z-axis; thereby cutting completely through and severing the
multiple, nested tubulars, cement or other encountered material in
tubular annuli, freeing the tubulars for removal to the surface;
producing a visually detectable drop of the tubulars (conductor) at
the surface.
27. The method of claim 25, not used in order to achieve complete
360 degree circumferential severance of all tubulars, but rather to
generate other desired cut(s) shape(s) or profile(s) in or through
tubular(s) comprising the steps of: generating a 360 degree
circumferential cut(s) through a single tubular; or generating a
360 degree circumferential cut(s) through a plurality of tubulars,
but not through all tubulars in the well of multiple, nested
tubulars; or generating a cut(s), shape(s) or profile(s) in a
single tubular; or generating a cut(s), shape(s) or profile(s) in a
plurality of tubulars, but not through all tubulars in the well of
multiple, nested tubulars; or generating a cut(s), shape(s) or
profile(s) through all tubulars in the well of multiple, nested
tubulars and through any cement or other encountered material in
the annuli of said tubulars, such cut(s), shape(s) or profile(s) to
include windows.
28. The method of 27, used in particularity with the inertia
reference system to verify a cut(s), shape(s) or profile(s) in a
specific location in the multiple, nested tubulars.
Description
REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn. 119
to application No. 61/131,874, filed Jun. 14, 2008, entitled
"Rotary milling casing cutter," which is hereby fully incorporated
by reference.
BACKGROUND OF THE INVENTION
[0002] When oil and gas wells are no longer commercially viable,
they must be abandoned in accord with government regulations.
Abandonment requires that the installed tubulars, including all
strings of tubing, pipe, casing or liners that comprise the
multiple, nested tubulars of the well must be severed below the
surface or the mud line and removed. Using explosive shape charges
to sever multiple, nested tubulars in order to remove them has
negative environmental impacts, and regulators worldwide are
limiting the use of explosives. Therefore, a need exists for
effective alternatives to the use of explosives for tubular
severance in well abandonment.
[0003] Mechanical blade cutting and abrasive waterjet cutting have
been implemented in response to new restrictive environmental
regulations limiting the use of explosives.
[0004] The prior and current art of utilizing mechanical blade
cutters from the inside of the innermost casing, cutting out
through each successive tubular of the multiple nested tubulars,
requires multiple trips in and out of the wellbore. Such mechanical
blade cutters require a rotary rig or some means of rotary drive in
order to rotate the work string to which the mechanical blade
cutter is attached. Rotary drive systems are both cumbersome and
expensive to have at the work site. An example of the prior art is
disclosed in U.S. Pat. No. 5,150,755, which is deficient in that
its mechanical blade cutters may break when they encounter
non-concentric tubulars, defeating its aim of severing multiple
strings of tubulars in a single trip. Another deficiency is the
limitation on the number of nested tubulars that may be severed by
this mechanical blade cutter. An "inner" and "outer" string are
described as being severable in one trip, if generally
concentrically positioned in relation to each other. There is no
claimed capability of severing a greater number of tubulars, for
example, five, nested tubulars, and certainly not in the event that
such multiple, nested tubulars were to be non-concentrically
positioned.
[0005] Most advances in the mechanical blade cutting art have
focused on cut chip control and efficiency, such as U.S. Pat. No.
5,181,564, or U.S. Pat. No. 5,899,268, rather than focusing the
fundamental issues of blade breakage and required, multiple,
undesired trips of the apparatus in and out of a well. Thus these
fundamental problems of prior art in mechanical blade cutting
persist.
[0006] When cutting multiple, nested tubulars of significant
diameters, for example 95/8 inches outside diameter through 36
inches outside diameter, with at least two other nested tubulars of
different sizes dispersed in between, the mechanical blade cutter
must be brought back to the surface where the smaller, just-used
cutting blades are exchanged for larger cutting blades. Exchanging
the smaller blades for larger blades allows the downhole cutting of
successively larger diameter multiple, nested tubulars.
[0007] The access of the downhole mechanical blade cutter requires
pulling the work string out of the wellbore and unscrewing the work
string joints where the mechanical blade cutter is attached to the
bottom work string joint. After exchanging the mechanical blade
cutter for a larger cutting blade, the work string joints are
screwed back together, one after another, and tripped back into the
wellbore. The mechanical blade cutter trip back into the wellbore
to the previous tubular cut location for additional cutting is
compromised because the length of the work string varies due to
temperature changes or occasionally human error in marking or
counting work string joints. Many installed multiple, nested
tubular strings in wells are non-concentric, meaning that the
nested tubulars are positioned off center in relation to the
innermost tubular, not having the same center diameter as the
smallest tubular. As a result of the multiple, nested tubulars
being stacked or clustered to one side, i.e. non-concentric to each
other, the density or amount of material being cut will vary
circumferentially during cutting. Mechanical cutter blades
sometimes experience breakage when cutting multiple, nested
tubulars positioned non-concentrically in relation to each other.
The blade cutter often breaks from the contact with the leading
edge of a partial segment of the casing that remains after another
segment of that casing has been cut away. The remaining portion of
the casing forms a "C" or horseshoe-type shape when viewed from
above. The blade cutter extends to its fullest open cut position
after moving across a less dense material or open space (because
that material has been cut away) and when the blade cutter impacts
the leading edge of the "C" shaped tubular, the force may break off
the blade. The breaking of a cutter blade requires again tripping
out and then back into the well and starting over at a different
location in the wellbore in order to attempt severing of the
multiple, nested tubulars. Non-concentric, multiple, nested
tubulars present serious difficulties for mechanical blade cutters.
Severing non-concentric multiple, nested tubulars can take a period
of days for mechanical blade cutters.
[0008] The prior art utilizing abrasive waterjet cutters also
experiences difficulties and failures to make cuts through
multiple, nested tubulars. Prior art methods and apparati are
disclosed in U.S. Pat. No. 7,178,598 and also U.S. Pat. No.
5,381,631. These disclosures relate to abrasive waterjet cutting
utilizing rotational movement in a substantially horizontal plane
to produce a circumferential cut in downhole tubulars. However, the
prior art in abrasive waterjet cutters for casing severance often
results in spiraling cuts with narrow kerfs in which the end point
of the attempted circumferential cut fails to meet the beginning
point of the cut after the cutting tool has made a full 360 degree
turn. In other words, the cut does not maintain an accurate
horizontal plane throughout the 360 degree turn, and complete
severance fails to be achieved. Another problem encountered by
prior and current art abrasive waterjet cutting is the inability to
cut all the way through the thicker, more widely spaced mass of
non-concentrically positioned tubulars. In this situation, the cut
fails to penetrate all the way through on a 360 degree
circumferential turn. A further disadvantage of traditional
abrasive waterjet cutting is that in order to successfully cut
multiple, nested tubulars downhole, air is required to be pumped
into the well bore to the area where the cutting is to take place,
allowing the abrasive waterjet tool to function in air and not be
impeded by water or wellbore fluid. The presence of fluid in the
cutting environment greatly limits the effectiveness of prior art
abrasive waterjet cutting.
[0009] Verification of severance using waterjet cutting is
accomplished by welding "ears" on the outside of the top portion of
the tubulars under the platform, attaching hydraulic lift
cylinders, heavy lift beams, and then lifting the entire conductor
(all tubulars) to verify complete detachment has been achieved.
When working offshore, this lifting verification process occurs
before costly heavy lift boats are deployed to the site. This
method of verification is time-consuming and expensive.
[0010] Prior art has been devised to mill windows via longitudinal,
vertical travel in casing. However, these milling methods do not
completely sever multiple, nested non-concentric tubulars for well
abandonment. A rotary milling method and apparatus was disclosed in
U.S. Pat. No. 7,537,055. This milling method uses a whipstock,
which must be deployed before the window milling process can begin.
A rotary mill is then actuated against one side of a tubular along
with a means of vertical travel, enabling a window to be cut
through the tubular. This prior art does not permit 360 degree
circumferential severance of multiple, nested tubulars and is not
suited for the purpose of well abandonment.
[0011] This invention responds to a need for a fast, inexpensive,
safe and environmentally benign means of completely severing
multiple, nested tubulars for well abandonment. This invention
overcomes the difficulties encountered by mechanical blade cutting,
abrasive waterjet cutting or other means of tubular milling in the
prior art. As well as being environmentally "green," this invention
is a more efficient, rigless technology deployed downhole for
severance of multiple, nested, non-concentric tubulars.
[0012] This invention relates to a methodology and apparatus for
cutting completely through multiple, nested strings of installed
tubulars, concentrically or non-concentrically (eccentrically)
positioned, by means of rotary milling. The downhole assembly is
deployed in the innermost tubular and proceeds to rotary mill
outward radially under computer control, cutting and completely
severing all installed tubing, pipe, casing and liners as well as
cement or other material encountered in the annuli between the
tubulars. The severance process occurs during one trip into the
well bore, obviating the need for retrieving and re-inserting the
downhole milling assembly before job completion.
BRIEF SUMMARY OF THE INVENTION
[0013] This invention provides methodology and apparatus for
efficiently severing all installed multiple, nested strings of
tubulars, either concentric or eccentric, as well as cement or
other material in the annuli between the tubulars, in a single trip
into a well bore. This invention overcomes the difficulties
encountered by prior art mechanical blade cutters by the rotary
mill cutter machining through metal tubulars and other encountered
material even if the nested tubulars and cement are not installed
concentrically.
[0014] The invention utilizes a computer-controlled robotic
downhole rotary mill to effectively generate a shape(s) or
profile(s) through, or completely sever in a 360 degree horizontal
circumferential plane, all installed tubing, pipe, casing and
liners as well as cement or other material encountered in the
annuli between the tubulars. This process occurs under programmable
robotic, computerized control, making extensive use of digital
sensor data to enable algorithmic, robotic actuation of the
downhole assembly and robotic rotary mill cutter.
[0015] With this invention, for the purposes of complete severance
of multiple, nested tubulars, the beginning and end points of the
cut are immaterial as the robotic rotary mill cutter generates a
wide swath or void. The severed casing will drop vertically at the
surface platform, providing visual verification of the severance.
The length, and therefore the reach of the spindle, is designed to
extend beyond the outermost casing with any number of additional
tubulars inside this outermost casing being extremely eccentrically
positioned, even with each tubular abutting each successively
nested tubular. This solves the cutting "reach" problems that are
encountered with abrasive waterjet cutting when the waterjet has
difficulty cutting through the thickest, most widely spaced mass of
the eccentrically positioned tubulars and cement. The precision,
programmable computer-controlled, sensor-actuated rotary milling
process will take much less time to complete severance than
mechanical blade cutters or abrasive waterjet cutting. The
extremely precise, actively adjusted rotary milling, profile
generation process greatly limits vibration and impact, preventing
the impact breakage that plagues mechanical blade cutters
encountering non-concentric, multiple, nested tubulars.
Furthermore, this invention's capability of being deployed and
completing the severance in one trip downhole provides a
significant advantage over prior art.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] Fig I. depicts the robotic rotary mill cutter 1. The robotic
rotary mill cutter 1, shows the position of the vertical Z-axis,
and the 360-degree horizontal rotary W-axis, and the milling
spindle swing arm pivotal Y-axis.
[0017] FIG. 2A and FIG. 2B depict the robotic rotary mill cutter 1
(see FIG. 1) enlarged and cut in half with the top of the robotic
rotary mill cutter 1 (see FIG. 1) shown in FIG. 2A and the lower
portion of robotic rotary mill cutter 1 (see FIG. 1) is shown in
FIG. 2B.
[0018] FIG. 3 depicts an expanded view of an inserted carbide mill
17 that will be attached to milling spindle swing arm 14 (see FIG.
2B) with a bolt (not shown) running through the inserted carbide
mill 17.
[0019] FIG. 4A depicts a top view of multiple casings (tubulars) 18
that are non-concentric.
[0020] FIG. 4B depicts an isometric view of non-concentric casings
(tubulars) 19.
[0021] FIG. 5A depicts the bottom of the lower portion of robotic
rotary mill cutter.
[0022] FIG. 5B depicts the lower portion of robotic rotary mill
cutter.
DETAILED DESCRIPTION OF THE INVENTION
[0023] This invention provides a method and apparatus for
efficiently severing all installed tubing, pipe, casing, and
liners, as well as cement or other encountered material in the
annuli between the tubulars, in one trip into a well bore.
[0024] Reference will now be made in detail to the present
embodiments of the disclosure, examples of which are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts (elements).
[0025] To help understand the advantages of this disclosure the
accompanying drawings will be described with additional specificity
and detail.
[0026] The present disclosure generally relates to methods and
apparatus for mill cutting through wellbore tubulars, including
casing or similar structures.
[0027] The method generally is comprised of the steps of
positioning a robotic rotary mill cutter inside the innermost
tubular in a pre-selected tubular or plurality of multiple, nested
tubulars to be cut, simultaneously moving the rotary mill cutter in
a predetermined programmed vertical X-axis, and also 360 degree
horizontal rotary W-axis, as well as the spindle swing arm in a
pivotal Y-axis arc.
[0028] In one embodiment of the present disclosure the vertical and
horizontal movement pattern(s) and the spindle swing arm are
capable of being performed independently of each other, or
programmed and operated simultaneously in conjunction with each
other. The robotic rotary mill cutter is directed and coordinated
such that the predetermined pattern is cut through the innermost
tubular beginning on the surface of said tubular with the cut
proceeding through it to form a shape or window profile(s), or to
cut through all installed multiple, nested tubulars into the
formation beyond the outermost tubular.
[0029] A profile generation system simultaneously moves the robotic
rotary mill cutter in a vertical Z-axis, and a 360-degree
horizontal rotary W-axis, and the milling spindle swing arm swing
arm in a pivotal Y-axis arc to allow cutting the tubulars, cement,
and formation rock in any programmed shape or window
profile(s).
[0030] The robotic rotary mill cutter apparatus is programmable to
simultaneously or independently provide vertical X-axis movement,
360 degree horizontal rotary W-axis movement, and spindle swing arm
pivotal Y-axis arc movement under computer control. A computer
having a memory and operating pursuant to attendant software,
stores shape or window profile(s) templates for cutting and is also
capable of accepting inputs via a graphical user interface, thereby
providing a system to program new shape or window profile(s) based
on user criteria. The memory of the computer can be one or more of
but not limited to RAM memory, flash memory, ROM memory, EPROM
memory, EEPROM memory, registers, hard disk, a removable disk, a
CD-ROM, floppy disk, DVD-R, CD-R disk or any other form of storage
medium known in the art. In the alternative, the storage medium may
be integral to the processor. The processor and the storage medium
may reside in an ASIC or microchip.
[0031] The computer of the present disclosure controls the profile
generation servo drive systems as well as the milling cutter speed.
The robotic rotary mill cutter requires load data to be able to
adjust for conditions that cannot be seen by the operator. The
computer receives information from torque sensors attached to
Z-axis, W-axis, Y-axis, and milling spindle drive motor, and makes
immediate adaptive adjustments to the feed rate and speed of the
vertical X-axis, the 360 degree horizontal rotary W-axis, and the
spindle swing arm pivotal Y-axis and the RPM of the milling spindle
motor.
[0032] Software in communication with sub-programs gathering
information from the torque devices, such as a GSE model Bi-Axial
transducer Model 6015 or a PCB model 208-M133, directs the
computer, which in turns communicates with and monitors the
downhole robotic rotary mill cutter and its attendant components,
and provides feeds and speeds simultaneously or independently along
the vertical Z-axis, and the 360 degree horizontal rotary W-axis,
as well as the pivotal spindle swing arm Y-axis arc movement.
[0033] The shape or window profile(s) are programmed by the
operator on a program logic controller (PLC), or personal computer
(PC), or a computer system designed for this specific use. The
integrated software via a graphical user interface (GUI) or touch
screen, such as a Red Lion G3 Series (HMIs), accepts inputs from
the operator and provides the working parameters and environment by
which the computer directs and monitors the robotic rotary mill
cutter.
[0034] The vertical Z-axis longitudinal computer-controlled servo
axis will use a hydraulic cylinder, such as the Parker Series 2HX
hydraulic cylinder, housing the MTS model M-series absolute analog
sensor for ease of vertical Z-axis longitudinal movements, although
other methods may be employed to provide up and down vertical
movement of the robotic rotary mill cutter.
[0035] In a still further embodiment of the present disclosure the
vertical Z-axis longitudinal computer-controlled servo axis may be
moved with a ball screw and either a hydraulic or electric motor,
such as a computer controlled electric servo axis motor, the Fanuc
D2100/150 servo, with encoder feedback to the computer system by an
encoder such as the BEI model H25D series incremental optical
encoder. Servo motors and ball screws are a know art and are widely
available from many sources.
[0036] In a still further embodiment of the present disclosure, the
vertical Z-axis longitudinal computer-controlled servo axis may be
moved with a rack and pinion, either electrically or hydraulically
driven. Rack and pinion drives are a know art and are widely
available from many sources.
[0037] The rotational computer controlled W-axis rotational
movement will be an electric servo motor, although other methods
may be employed. The rotational computer-controlled W-axis servo
motor, such as a Fanuc model D2100/150 servo, provides 360-degree
horizontal rotational movement of the robotic rotary mill cutter
through a specially manufactured slewing gear.
[0038] The Y-axis pivotal milling spindle swing arm
computer-controlled servo axis will use a hydraulic cylinder for
ease of use, although other methods may be employed. The Y-axis
pivotal milling spindle swing arm computer-controlled servo axis,
may utilize the Parker Series 2HX hydraulic cylinder, housing the
MTS model M-series absolute analog sensor inside the hydraulic
cylinder to provide position feedback to the computer controller
for pivotal spindle swing arm Y-axis arc movement.
[0039] In a still further embodiment of the present disclosure that
an inertia reference system such as, Clymer Technologies model
Terrella6 v2, will provide information that the robotic rotary mill
cutter is performing the movements commended by the computer
controller as a verification reference. If the reference shows a
sudden stop, the computer will go into a hold action stopping the
robotic rotary mill cutter and requires operator intervention
before resuming milling operations.
[0040] The methods and systems described herein are not limited to
specific sizes or shapes. Numerous objects and advantages of the
disclosure will become apparent as the following detailed
description of the multiple embodiments of the apparatus and
methods of the present disclosure are depicted in conjunction with
the drawings and examples, which illustrate such embodiments.
[0041] One advantage of the present disclosure over the prior art
is that the attendant costs of cutting through the wellbore
tubulars, through casings, cement and into formation rock, will be
relatively nominal as compared to current practices. The robotic
rotary mill cutter may significantly decrease site and personnel
time.
[0042] Fig I. depicts the robotic rotary mill cutter 1. The robotic
rotary mill cutter 1, shows the position of the vertical Z-axis,
and the 360-degree horizontal rotary W-axis, and the milling
spindle swing arm pivotal Y-axis.
[0043] FIG. 2A and FIG. 2B depict the robotic rotary mill cutter 1
(see FIG. 1) enlarged and cut in half with the top of the robotic
rotary mill cutter 1 (see FIG. 1) shown in FIG. 2A and the lower
portion of robotic rotary mill cutter 1 (see FIG. 1) shown in FIG.
2B.
[0044] FIG. 2a depicts a collar 2 that is used to attach the
umbilical cord (not shown) and cable (not shown) to the body of
robotic rotary mill cutter 1, (see FIG. 1). Collar 2 may be
exchanged to adapt to different size work strings (not shown) in
case of the need for emergency removal of the robotic rotary mill
cutter 1, (see FIG. 1). After the robotic rotary mill cutter 1,
(see FIG. 1) is in the cut location, locking hydraulic cylinders 3,
FIG. 2a are energized to lock the robotic rotary mill cutter 1,
(see FIG. 1) into the well bore (not shown). After the locks 3 have
been energized, Z-axis hydraulic cylinder 6 is moved to a down
position where hydraulic cylinder 6, piston rod 4 allows the Z-axis
slide 5 to extend.
[0045] FIG. 2b a W-axis servo motor 8 rotates the W-axis under
control of the computer (not shown). W-axis rotating body 10 houses
the milling spindle swing arm 14 and the milling spindle swing arm
is driven by motor 11 also housed in the W-axis rotating body 10.
Milling spindle swing arm 14 is driven by motor 11 through a
half-shaft 12 such as Motorcraft model 6L2Z-3A427-AA.
[0046] Half-shaft 12 has a C.V. joint (not shown) that allows
milling spindle swing arm 14 to pivot in an arc from pivot bearing
13 that goes through W-axis rotating body 10. Milling spindle swing
arm 14 is moved by Y-axis hydraulic cylinder 16. The rotation of
W-axis rotating body 10 requires a swivel joint 9, such as Rotary
Systems Model DOXX Completion, to allow power and sense lines (not
shown) to the motor 11, Y-axis hydraulic cylinder 16 and load cell
sense wires (not shown). Carbide cutter 15 is mounted to the
milling spindle swing arm 14 (see 2B) and is moved by Y-axis
cylinder 16 into the cut under computer control.
[0047] FIG. 3 depicts an expanded view of an inserted carbide mill
17 that will be attached to milling spindle swing arm 14 (see FIG.
2B) with a bolt (not shown) running through the inserted carbide
mill 17.
[0048] FIG. 4A depicts a top view of nested multiple casings
(tubulars) 18 that are positioned non-concentrically.
[0049] FIG. 4B depicts an isometric view of nested multiple casings
(tubulars) 19 that are positioned non-concentrically.
[0050] FIG. 5A depicts a view of the lower portion body of robotic
rotary mill cutter 1, (see FIG. 1) before entering the nested
multiple casings (tubulars) 18 (see 4A).
[0051] FIG. 5B shows the nested multiple casings (tubulars) 18 (see
4A) side view shows the void that has been removed by the profile
generation system (not shown) that simultaneously moved the robotic
rotary mill cutter 1 (see FIG. 1) in a vertical Z-axis, and a
360-degree horizontal rotary W-axis, and the milling spindle swing
arm 14 (see 2B) in a pivotal Y-axis arc to allow cutting the
tubulars, cement, and formation rock in any programmed shape or
window profile(s) thereby cutting through the multiple casing
(tubulars) 18 (see 4A), cement or other encountered material in
casing annuli (not shown).
* * * * *