U.S. patent application number 15/508916 was filed with the patent office on 2017-07-20 for battery operated autonomous scale removal system for wells.
The applicant listed for this patent is AARBAKKE INNOVATION A.S.. Invention is credited to Henning Hansen.
Application Number | 20170204702 15/508916 |
Document ID | / |
Family ID | 55351115 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170204702 |
Kind Code |
A1 |
Hansen; Henning |
July 20, 2017 |
BATTERY OPERATED AUTONOMOUS SCALE REMOVAL SYSTEM FOR WELLS
Abstract
An autonomously operated well intervention tool system includes
a lubricator sealingly affixable to an upper end of a well. The
lubricator has a latch at an upper end thereof. A well intervention
tool system is releasably matable with the latch. The well
intervention tool system comprises a wellbore intervention device
at a longitudinal end thereof. The lubricator has at least one
isolation valve to close fluid communication between the well and
the lubricator.
Inventors: |
Hansen; Henning; (Dolores,
ES) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AARBAKKE INNOVATION A.S. |
Bryne |
|
NO |
|
|
Family ID: |
55351115 |
Appl. No.: |
15/508916 |
Filed: |
July 14, 2015 |
PCT Filed: |
July 14, 2015 |
PCT NO: |
PCT/US15/40262 |
371 Date: |
March 4, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62038930 |
Aug 19, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 47/00 20130101;
E21B 37/00 20130101; E21B 33/068 20130101; E21B 23/06 20130101 |
International
Class: |
E21B 37/00 20060101
E21B037/00; E21B 33/068 20060101 E21B033/068 |
Claims
1. An autonomously operated well intervention tool system,
comprising: a lubricator sealingly affixable to an upper end of a
well, the lubricator comprising a latch at an upper end thereof; a
well intervention tool system releasably matable with the latch,
the well intervention tool system comprising a wellbore
intervention device at a longitudinal end thereof; and wherein the
lubricator comprises at least one isolation valve to close fluid
communication between the well and the lubricator.
2. The system of claim 1 wherein the latch comprises an electrical
connector to enable supply of electrical power to the well
intervention tool system.
3. The system of claim 1 wherein an electrical connector is located
anywhere within the lubricator system.
4. The system of claim 1 wherein the wellbore intervention device
comprises a scale removal device.
5. The system of claim 1 wherein the wellbore intervention device
comprises at least one of a production logging instrument and a
plug or packer setting tool.
6. The system of claim 1 wherein the well intervention tool system
comprises at least one swab cup on an exterior surface thereof to
enable lifting the well intervention tool system by upward movement
of fluid in the well.
7. The system of claim 1 wherein the well intervention tool system
comprises a powered propulsion unit to enable movement of the well
intervention tool system along an interior of the well.
8. The system of claim 1 wherein the lubricator comprises at least
one equalization valve in a fluid communication line extending
between the well and the lubricator.
9. The system of claim 1 wherein the lubricator comprises at least
one pressure relief valve configured to selectively vent pressure
inside the lubricator.
10. The system of claim 1 wherein the scale removal device
comprises at least one of a chemical storage and release mechanism,
motor-rotated blades, motor-rotated abrasive mills, an electric
shock discharge device, an acoustic device and a heater.
11. The system of claim 1 wherein the well intervention tool system
comprises means for automatically stopping the well intervention
tool system at a selected position in the well.
12. A method for performing intervention operations in a well,
comprising: latching a well intervention tool system in a
lubricator, the lubricator comprising at least one isolation valve
at a well connection end thereof, the lubricator comprising at
least one pressure equalization valve, the lubricator comprising at
least one pressure relief valve; closing the at least one isolation
valve; affixing the lubricator to an upper end of a well; opening
the at least one pressure equalization valve to impart pressure in
the well to an interior of the lubricator; opening the at least one
isolation valve; releasing the well intervention tool system to
move into the well to selected depth therein; operating a wellbore
intervention device on the well intervention tool system; and
returning the well intervention tool system to the lubricator.
13. The method of claim 12 wherein the returning the well
intervention tool system to the lubricator comprises lifting the
well intervention tool system using flow of fluid in the well.
14. The method of claim 12 wherein the returning the well
intervention tool system to the lubricator comprises operating a
propulsion device in the well intervention tool system.
15. The method of claim 12 further comprising closing the at least
one isolation valve, opening a pressure relief valve to vent
pressure from within the lubricator and removing the lubricator
from the well.
16. The method of claim 12 further comprising closing the at least
one isolation valve, opening a pressure relief valve to vent
pressure from within the lubricator, removing a sealing cap from an
upper end of the lubricator and retrieving the well intervention
tool system from within the lubricator.
17. The method of claim 12 further comprising attaching an
electrical cable to a connector forming part of a latch used to
retain the well intervention tool system in the lubricator and
applying electrical power to the electrical cable to recharge at
least one battery in the well intervention tool system.
18. The method of claim 12 wherein the wellbore intervention device
comprises a scale removal device.
19. The method of claim 12 wherein the wellbore intervention device
comprises at least one of a production logging instrument and a
packer or plug setting tool.
Description
BACKGROUND
[0001] This disclosure relates generally to the field of a
non-tethered autonomous well intervention tool system for removing
scale and similar from a wellbore. The wellbore can be subsea, on
an offshore platform or on land. More specifically, the present
disclosure relates to a battery operated electrical tool for
dissolving mineral build-up in a wellbore, where the tool is
stored, deployed from and received in a lubricator and charging
system mounted on top of a wellhead (Christmas tree). The wellbore
intervention tool system may also perform other wellbore
operations, e.g., production logging, setting and retrieval of
plugs, and other intervention operations known in the art. The
system may operate without the presence of a human operator at the
well site, either remotely operated or autonomously at
pre-determined times.
[0002] Buildup of scale and paraffin is a frequent problem in
producing hydrocarbon wells, where such build up causes drop or
total halt of production as well as malfunction of wellbore
completion components, for example, downhole safety valves. To
remove scale and paraffin deposits, wireline is rigged up on top of
the wellbore, followed by an intervention where electrical or
mechanical impact based tools are run into the wellbore to hammer
loose the scale or cut the paraffin built up. This is a slow
process due to the nature of the tools being used, but not least
due to the time required to rig up and down the intervention
valves, lubricator and so on. In addition, well production is lost
due to the required well "shut in" (stopping of fluid production)
during rigging operation. The process may also be expensive, where
the cost of performing an intervention in a subsea well can amount
to tens of millions of United States dollars, plus a significant
lost income for the duration of the intervention.
[0003] Due to the foregoing considerations, failures of wellbore
components, for example, downhole safety valves, also take place as
a result of intentionally infrequent scale removal, causing the
production tubing, etc., to become partially or completely
non-functional.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1. illustrates scale in a tube, where it can be
understood that this will reduce or totally prevent flow through a
tube as well as cause wellbore components to malfunction.
[0005] FIG. 2 illustrates a wellhead with an attached wellhead
("christmas tree") and a lubricator/valve system installed on top
of the christmas tree. Within the lubricator, a wellbore
intervention tool system is mounted. Scale build up is indicated
within a conduit called production tubing.
[0006] FIG. 2A shows an enlarged view of an example intervention
tool system
[0007] FIG. 3 illustrates that valves in the lower end of the
lubricator system have been opened, followed by a wellbore
intervention tool moving into the wellbore.
[0008] FIG. 4 illustrates that one or both valves in the lower
section of the lubricator system have been closed, so that the well
can be flowed at a low rate with the intervention tool being
downhole. Scale removal may be started.
[0009] FIG. 5 illustrates that the intervention tool is transported
up-hole, either by producing the well or by a built in propulsion
drive.
[0010] FIG. 6 illustrates that the intervention tool has latched
into the top section of the lubricator/valve system, with both
valves closed and well brought back to normal production.
DETAILED DESCRIPTION
[0011] Therefore the present disclosure sets forth a possible
solution to removing scale or paraffin in a well where the scale or
paraffin removal is performed more frequently than may be performed
using conventional wireline conveyed tools. Increased frequency of
scale or paraffin deposits may prevent excessive buildup of such
scale or paraffin deposits. Scale or paraffin removal at more
frequent intervals may be performed by a system mounted on top of
the wellhead, where a lubricator, isolated from the wellhead by
valves built into the lower section of the intervention system,
contains a scale or paraffin removal tool that can be deployed into
the wellbore when required.
[0012] The wellbore tool intervention system may include a scale or
paraffin removal tool with required ancillary instrumentation
attached, such as, for example, a battery package, a wet-mating
electrical coupler, a propulsion system, etc. The wellbore tool
intervention system may be deployed into the wellbore from a
storage place within the lubricator and may be returned to the
lubricator by causing fluid to flow from the formations external to
the well thence into the well. In some embodiments, the wellbore
intervention tool system may contain a propulsion system built in
that returns the wellbore tool system to the lubricator when
required.
[0013] Electrical, hydraulic or pneumatic operated impact (e.g.
hammer, so called "broach" and similar) based scale removal tools
can be coupled to the wellbore intervention tool system. A wellbore
intervention tool system according to the present disclosure allows
more frequent wellbore scale or paraffin removal operations than
would be ordinarily performed using interventions from a vessel,
workover rig or a drilling rig. More frequent deposit removal may
result in the scale or paraffin deposits being of less extent than
would occur with less frequent intervention; such more frequent
deposit removal ensures improved production of hydrocarbons from
the well.
[0014] To perform a wellbore intervention, pressure equalizing
between the wellbore and the lubricator may be performed, followed
by opening of valves between the lubricator and the wellhead. This
will enable the wellbore intervention tool system to drop, or drive
down, into the wellbore where it reaches a restriction caused by
scale or paraffin. Then the removal of such restriction will be
commenced, until the restriction has been removed or until an
internal power source (e.g., batteries) is exhausted. When the
foregoing takes place, the wellbore intervention tool system may be
transported up to the lubricator again by a built in "swab cup"
that uses fluid flow from the wellbore to lift the wellbore
intervention tool system. When reaching the wellhead, the wellbore
intervention tool system will be further pushed up into the
lubricator and latch onto a holding device and/or an electrical
coupler enabling battery recharging.
[0015] After the wellbore intervention tool system has been
returned to the lubricator, the valves between the lubricator and
the wellhead can be closed and pressure tested, so that the well
can commence fluid production again.
[0016] When scale or paraffin removal is required again, the above
sequence may be repeated.
[0017] For those skilled in the art of wellbore interventions, it
will be understood that the method described herein may also be
used for other type interventions, e.g., memory type production
logging, and other intervention operations.
[0018] FIG. 1. illustrates scale 14 in a tube 12. The tube 12 may
be, for example, a wellbore production tubing or "velocity string."
It will be appreciated that the scale 14 will reduce or totally
prevent flow through the tube 14. The scale 14 may also cause
wellbore components to malfunction. Such scale needs to be removed,
where various methods can be used, as for example mechanically
breaking the scale, pulsed electrical energy pulverizing the scale,
release of scale-dissolving chemicals, or abrasive means such as
milling.
[0019] FIG. 2 illustrates a wellhead 20, for example a sea bottom
wellhead with an attached christmas tree (e.g., valves 30 and 32).
A lubricator system 22 may be affixed to the upper end of the
wellhead. The lubricator system 22 may include isolation valves 22A
such as gate valves to selectively pressure isolate the lubricator
system 22 from the wellhead 20. The isolation valves 22A may be
operated by respective actuators 22B. The actuators 22B may be
electrically, pneumatically or hydraulically operated, for example.
The lubricator system 22 may include pressure equalization valves
28 that connect the interior of the lubricator system to below each
of the isolation valves 22A. The pressure equalization valves 28
may also be actuated electrically, hydraulically or pneumatically.
The isolation valves 22A and the pressure equalization valves 28
may be operated by a controller 29. The controller 29 may be
operated using, for example, telemetry from the water surface or
electrical connection using a remotely operated vehicle (ROV). The
lubricator system 22 may also include a pressure relief valve 24 to
enable release of pressure from the interior of the lubricator
system after the well intervention tool system 10 is retrieved into
the lubricator system 22. The pressure relief valve 24 may also be
electrically, hydraulically or pneumatically operated and may be
controlled by the controller 29.
[0020] The upper end of the lubricator system 22 may include a
sealing cover 22D that is retained in place on the upper end of the
lubricator system 22 and is pressure sealed. The sealing cover 22D
may include an automatically operable latch 22E to retain the
wellbore intervention tool system 10 when it is retrieved into the
lubricator system 22. The latch 22E may include electrical
connections (not shown separately) for providing electrical power
to the wellbore intervention tool system 10, e.g., to recharge
batteries therein (see FIG. 2A).
[0021] The sealing cover 22D may have a profile for a retrieval and
running tool, a receptacle 22F for an electrical cable from an
external power source as well as various sensors for monitoring
pressure, etc. It may also contain a telemetry system for
transmitting and receiving commands and data from a surface vessel
or the like. The sealing cap 22D may also be removed, so that a
wellbore intervention pressure control system (with riser, etc.)
can be landed on top of the lubricator system 22, followed by the
possibility of deploying and setting plugs and other equipment in
the wellbore. Setting a plug within a tubing hanger or further down
into the wellbore tubing 14 may enable a safe removal of the
complete lubricator system 22 if such is required.
[0022] The isolation valves 22A valve system on the lower end of
the lubricator system 22 may be used for pressure testing of the
lubricator system 22 and enable the well to operate normally
without subjecting the lubricator system 22 to wellbore production
fluids and pressure when the wellbore intervention tool system 10
is not in use.
[0023] FIG. 2A shows the wellbore intervention tool system 10 in
more detail. The wellbore intervention tool system 10, hereinafter
"tool" for convenience, may include a self-contained power supply
10E such as batteries within a pressure sealed housing 11. A
control and power module 10F disposed in the housing 11 may be used
to operate a wellbore intervention device 10A. In the present
embodiment, the wellbore intervention device may be a scale removal
device disposed proximate the bottom of the housing 11. The scale
removal device may be any type known in the art, including a
chemical storage and release mechanism, motor-rotated blades or
abrasive mills, electric shock (sparker) discharge devices,
acoustic devices, heater(s) to remove paraffin deposits, or any
other such device for removal of deposits in the tubing (12 in FIG.
1). The tool 10 may include combinations of any or all of the
foregoing as well. The tool 10 may include a propulsion device 10G,
such as a fluid operated jet or a propeller to cause the tool 10 to
move within the tube 14 during operations if gravity is
insufficient to move the tool 10 downwardly to the depth of any
obstruction, and to return the tool 10 to the lubricator system (22
in FIG. 2) if fluid flow from the well is insufficient to lift the
tool 10. The housing 11 may include annular seals 10D such as swab
cups to enable free movement of the tool 10 downwardly, but may
seal to engage the interior of the tubing (14 in FIG. 1) to enable
fluid flow into the well to lift the tool into the lubricator
system (22 in FIG. 2). The upper end of the housing 11 may include
a mating latch 10B to engage the latch (22E in FIG. 2) in the
lubricator system sealing cover (22D in FIG. 2). The housing 11 may
include centralizers 10C to enable relatively free movement of the
tool 10 in the tubing (14 in FIG. 2) and to keep the tool 10
centered in the tubing for proper operation of the scale removal
device.
[0024] Scale or paraffin build up may be indicated within the
production tubing (14 in FIG. 2), for example, by a decrease in
fluid production from the well. Thus it may be necessary to deploy
the tool 10. The tool 10 may be installed into the lubricator
system (22 in FIG. 2) prior to installing the lubricator system (22
in FIG. 2) onto the wellhead (20 in FIG. 2) or the tool 10 may be
installed into the lubricator system (22 in FIG. 2) by unlatching
and removing the sealing cover (22D in FIG. 2). Retrieval of the
tool 10 may be performed by unlatching and retrieving the entire
lubricator system with the tool 10 inside the lubricator system, or
by unlatching the sealing cover (22D in FIG. 2) and retrieving the
tool 10. It is also possible to perform tool replacement using an
ROV in marine operations where the wellhead is on the water
bottom.
[0025] In other embodiments, the wellbore intervention device 10A
may be any other type of wellbore tool, including, without
limitation, a production logging instrument, a plug or packer
setting tool or a video camera.
[0026] FIG. 2 shows the tool 10 engaged with the latch 22E and the
isolation valves 22A and pressure equalization valves 28 closed so
that the well can operate normally. When it is determined that
deployment of the tool is necessary, FIG. 3 illustrates that the
pressure equalization valves 28 may be opened to equalize pressure
in the well with the pressure in the lubricator system 22. The
isolation valves 22A may then be opened and the latch 22E may be
released to enable the tool 10 to move downwardly through the well
tubing 14. Movement of the tool 10 into the wellbore may be by
gravity or by a propulsion device (10G in FIG. 2A) in the tool 10.
It is also here illustrated that the tool performs scale or
paraffin removal.
[0027] FIG. 4 illustrates that one or both of the isolation
valves28 has been closed, so that well can be flowed at low rate
with the tool 10 being in the wellbore. Scale or other deposit
removal may then be started by operating the deposit removal device
10A. When the tool 10 reaches the area of restriction caused by
scale or paraffin, the tool 10 performs the removal of this
restriction as explained above. As the deposits are removed and the
flow restriction is alleviated, the tool 10 will by move further
down into the wellbore by gravity (or by use of the propulsion
device 10G in FIG. 2A, e.g., for highly inclined or horizontal
wells) The tool 10 control and power module (10F in FIG. 2A) may
include an internal mechanism that detects length of free fall,
e.g., integrating accelerometers or an integrating velocity meter
and/or area with no unwanted restriction. The power and control
module may be programmed to enable the tool 10 to stop itself,
e.g., by energizing its swab cups (10D in FIG. 2A), a mechanical
breaking mechanism or the propulsion device (10G in FIG. 2A.
[0028] A device preventing the tool 10 from going further into the
wellbore than a selected depth may also be installed in the
wellbore, for example, a narrow internal diameter packer or similar
restriction. Such a device can be set up to trigger the power and
control module (10F in FIG. 2A) to cause the tool 10 to return the
lubricator/system 22. An example of such device may be a contact
switch, shown at 13 in FIG. 2A which would not be triggered by
scale or other deposits, but would be triggered by contact with a
packer or similar internal diameter restriction.
[0029] FIG. 5 illustrates that the tool 10 is transported up-hole,
either by producing the well at low flow rate or by the propulsion
device (10G in FIG. 2A). The isolation valves 28 are opened to
enable the tool 10 to enter the lubricator system 22.
[0030] FIG. 6 illustrates that the tool 10 has latched into the
lubricator system 22 on the latch 22E in the sealing cover 22D. At
such time the isolation valves 28 may be closed and the well
brought back to normal production. The tool 10 is now coupled to
the electrical coupler (part of latch 22E) in the sealing cover 22D
so that the batteries (10E in FIG. 2A) can be charged. In some
embodiments it may be possible to retrieve logged data and transmit
new commands to the tool 10 through the electrical connector
22F.
[0031] After the isolation valves 28 are closed, pressure inside
the lubricator system 22 may be released using the pressure relief
valve 24. Such may be performed prior to any required removal of
the sealing cap 22D or the lubricator system 22 from the wellhead
20.
[0032] While the invention has been described with respect to a
limited number of embodiments, those skilled in the art, having
benefit of this disclosure, will appreciate that other embodiments
can be devised which do not depart from the scope of the invention
as disclosed herein. Accordingly, the scope of the invention should
be limited only by the attached claims.
* * * * *