U.S. patent application number 12/308170 was filed with the patent office on 2009-10-29 for wellbore tool for filling, circulating and backflowing fluids.
Invention is credited to Sverre Bakken, Sven Revheim.
Application Number | 20090266532 12/308170 |
Document ID | / |
Family ID | 38522675 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090266532 |
Kind Code |
A1 |
Revheim; Sven ; et
al. |
October 29, 2009 |
Wellbore Tool for Filling, Circulating and Backflowing Fluids
Abstract
The present invention relates to a tool (1) for filling,
circulating and backflowing fluids in a pipeline being run into or
out of a wellbore, the tool (1) including an elongate,
telescopically acting body (2), a sealing element (14) arranged for
sealing between the tool (1) and the pipeline (6) when the tool is
being run into the pipeline, and a valve means (19) arranged for
being closed when the tool is being pulled out of the pipeline (6),
the tool (1) further being provided with a through channel. The
invention is characterized in that the elongate, telescopically
acting body (2) comprises a running head (3) at the lower end
thereof, the valve means (19) being installed in the running head
(3) and including a hydraulically actuatable ball valve adapted for
being operable to an open position when running head (3) is run
into the upper end of the pipeline (6), the hydraulic actuatable
ball valve being adapted for closing when the running head (3) is
pulled out of the pipeline (6), one or more sensors (9), adapted
for measuring how far into the pipeline (6) the running head (3) is
located, being positioned along the elongate, telescopically acting
body (2).
Inventors: |
Revheim; Sven; (Hafrsfjord,
NO) ; Bakken; Sverre; (Stavanger, NO) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
1030 15th Street, N.W.,, Suite 400 East
Washington
DC
20005-1503
US
|
Family ID: |
38522675 |
Appl. No.: |
12/308170 |
Filed: |
March 22, 2007 |
PCT Filed: |
March 22, 2007 |
PCT NO: |
PCT/NO2007/000112 |
371 Date: |
April 7, 2009 |
Current U.S.
Class: |
166/53 ; 166/66;
166/90.1 |
Current CPC
Class: |
E21B 21/106 20130101;
E21B 21/01 20130101; E21B 34/063 20130101; E21B 19/16 20130101 |
Class at
Publication: |
166/53 ;
166/90.1; 166/66 |
International
Class: |
E21B 21/00 20060101
E21B021/00; E21B 21/10 20060101 E21B021/10; E21B 19/00 20060101
E21B019/00; E21B 43/00 20060101 E21B043/00; E21B 47/00 20060101
E21B047/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2006 |
NO |
2006 1333 |
Claims
1. A tool (1) for filling, circulating and backflowing fluids in a
pipeline being run into or out of a wellbore, the tool (1)
comprising an elongate, telescopically acting body (2), a sealing
element (14) arranged for sealing between tool (1) and the pipeline
(6) when this has been inserted into the pipeline, and a valve
means (19) arranged for being closed when the tool is being pulled
out of pipeline (6), the tool (1) further being provided with a
through channel, characterized in that the elongate, telescopically
acting body (2) includes a running head (3) on the lower end
thereof, wherein valve means (19) is positioned in running head (3)
and wherein valve means (19) includes a hydraulically actuatable
ball valve arranged for being operable to open position when
running head (3) is run into the upper end of pipeline (6), wherein
the hydraulically actuatable ball valve is arranged for closing
when running head (3) is pulled out of pipeline (6), one or more
sensors (9), adapted for measuring how far into pipeline (6)
running head (3) is located, being arranged along the elongate,
telescopically acting body (2).
2. The tool (1) of claim 1, characterized in that the tool
comprises drive means (11) selectively retracting or extending the
elongate, telescopically acting body (2).
3. The tool (1) of claim 1, characterized in that the tool is
provided with locking means arranged for locking the elongate,
telescopically acting body (2) in a desired, extended position.
4. The tool (1) of claim 3, characterized in that the locking means
include slips (23) arranged for locking the elongate,
telescopically acting body (2) in a desired, extended position.
5. The tool (1) of claim 1, characterized in that the sealing
element (14) is positioned on the running head (3), two metal rings
(12, 13) being provided at each side of sealing element (14), the
metal rings (12, 13) being arranged in such a manner that when
sealing element (14) is squeezed between metal rings (12, 13),
sealing element (14) will expand outwards to seal against the
interior of pipeline (6), the radius of metal rings (12, 13) and
sealing element (14) being chosen so that the sealing element (14)
does not project outside metal rings (12, 13) when said metal rings
are not squeezed together.
6. The tool (1) of claim 5, characterized in that separate drive
means (22) are provided for squeezing metal rings (12, 13)
together.
7. The tool (1) of claim 2, characterized in that said sensors (9)
are adapted for transmitting signals to the drive means (11), the
drive means (11) being arranged to stop when the sensors (9)
transmit a signal indicating that the running head (3) has been run
sufficiently far into the pipeline (6).
8. The tool (1) of claim 5, characterized in that the radii of the
metal rings (12, 13) and the sealing element (14) are selected so
that the sealing element (14) does not project outside the metal
rings (12, 13) when said metal rings are not squeezed together.
9. The tool (1) according to claim 1, characterized in that the
tool is provided with means measuring the distance from the
gripping point of the elevator on the pipeline (6) to the pipeline
end (8).
10. The tool (1) according to claim 1, characterized in that the
tool is provided with means measuring the level of liquid in the
pipeline (6).
11. The tool (1) of claim 10, characterized in that the means
measuring the level of liquid in the pipeline (6) is/are disposed
on the running head (3).
12. The tool (1) of claim 1, characterized in that the tool
comprises an electronic signal control module receiving,
processing, and communicating signals from the sensors and drive
means of the tool (1), the electronic signal control module of the
tool (1) communicating, wirelessly or not, with an electronic
signal control module at the drilling floor, said two electronic
signal control modules being designed for cooperatively performing
the tasks of the tool (1).
13. The tool (1) of claim 9, characterized in that the tool
comprises an electronic signal control module receiving, processing
and communicating signals from the sensors and drive means of the
tool (1), the electronic signal control module of the tool (1)
communicating, wirelessly or not, with an electronic signal control
module at the drilling floor, said two electronic signal control
modules being adapted for cooperatively performing the tasks of
tool (1), wherein the electronic signal control module of the tool
(1), on the receipt of a particular signal from the electronic
signal control module at the drilling floor, causes the tool 1, by
means of measurements of the distance from the gripping point of
the elevator on the pipeline (6) to the pipeline end (8),
measurements from the sensors (9), and optionally also by means of
measurements of the level of liquid in the pipeline (6), to find an
optimal position for the running head (3) relative to the pipeline
(6), the position corresponding to one of the following positions:
a) a standby position if filling, emptying, or circulation is not
to be performed, b) a filling position, c) an emptying position, or
d) a circulating position, the current position and the various
measurements being continuously updated and mediated to the
electronic signal control module at the drilling floor, so that the
operation and state of the tool (1) may be monitored and verified
at any time by the electronic signal control module at the drilling
floor and/or an operator.
14. The tool (1) of claim 2, characterized in that the tool is
provided with locking means arranged for locking the elongate,
telescopically acting body (2) in a desired, extended position.
15. The tool (1) of claim 3, characterized in that said sensors (9)
are adapted for transmitting signals to the drive means (11), the
drive means (11) being arranged to stop when the sensors (9)
transmit a signal indicating that the running head (3) has been run
sufficiently far into the pipeline (6).
16. The tool (1) of claim 4, characterized in that said sensors (9)
are adapted for transmitting signals to the drive means (11), the
drive means (11) being arranged to stop when the sensors (9)
transmit a signal indicating that the running head (3) has been run
sufficiently far into the pipeline (6).
17. The tool (1) according to claim 2, characterized in that the
tool is provided with means measuring the distance from the
gripping point of the elevator on the pipeline (6) to the pipeline
end (8).
18. The tool (1) according to claim 3, characterized in that the
tool is provided with means measuring the distance from the
gripping point of the elevator on the pipeline (6) to the pipeline
end (8).
19. The tool (1) according to claim 4, characterized in that the
tool is provided with means measuring the distance from the
gripping point of the elevator on the pipeline (6) to the pipeline
end (8).
20. The tool (1) according to claim 5, characterized in that the
tool is provided with means measuring the distance from the
gripping point of the elevator on the pipeline (6) to the pipeline
end (8).
Description
[0001] The present invention relates to a tool for filling,
circulating and backflowing fluids in a pipeline being run into or
out of a wellbore.
[0002] U.S. Pat. No. 6,722,425 relates to a tool for filling and
backflowing fluids in a pipeline being run into or out of a
wellbore. The tool according to this publication comprises an
elongate, telescopically acting body, a sealing element for sealing
between the tool and the pipeline into which the tool is run, as
well as a fluid flow actuated valve means arranged for closing when
the tool is pulled out of the pipeline. The purpose of the valve
means is to prevent the spill of fluid when the tool is pulled out
of the pipeline. Also, the tool is provided with a through channel
within which the valve means is installed, openings formed at each
end of the channel and at each side of the sealing element
providing a fluid flow path through the tool, allowing fluids to be
filled into and discharged from the pipeline.
[0003] When pipe sections, such as casing, are run into a wellbore,
a check valve will cause the casing to be filled with mud from the
drilling floor as pipe sections are being lowered into the
wellbore. As the pipe sections are run into the wellbore, a
corresponding volume, plus the volume of the casing steel, of mud
will be displaced in the wellbore, and this displaced mud needs to
be collected and stored in the return pit, where it is prepared for
further use.
[0004] Today, most wells are being drilled using steerable drilling
machines allowing for a much more extended reach drilling than in
the past. A well is commonly drilled through several layers or
zones of rock having different thickness and characteristics, the
main portion of the well generally following a wavy or helical path
in an essentially horizontal direction. This fact, as well as the
increasing demand for ever larger inner diameter casing in order to
increase the recovery rate, makes it more difficult to run the
casing into the wellbore to the desired depth while maintaining
control of the well.
[0005] If the wellbore walls have zones of weakness, mud will be
able to migrate out of the wellbore and into the surrounding
formations. This results in a loss of mud and pressure in the well.
In order to solve this problem, mud containing sealing substances
is circulated in the well, whereby the sealing substances penetrate
into the weak zones of the formation recovering the integrity of
the wellbore.
[0006] When pipe sections such as casing are run into a well, the
casing must be refilled with mud in order to prevent the casing
from collapsing. Mud is also circulated through the casing in order
to reduce the friction and thereby ease the process of lowering the
casing to the desired depth. The circulation of mud also effects a
cooling that facilitates the process of cementing the casing to the
wellbore walls.
[0007] It has turned out that the implementation of efficient mud
filling and circulation operations, in which, in particular, the
circulation time and frequency are sought kept at a maximum, is the
single most important factor to achieve a successful result when
deep wells are to be drilled and lined with casing.
[0008] The above conventional filling and circulating operations
are carried out using elongated, tubular tools that are connected
to the casing section rising through the drilling floor. The tool
includes a pipe stub or tube that is run some length into the pipe
section, as well as sealing elements sealing the connection between
the tool and the pipe section.
[0009] The conventional tools must be mounted on the traveling
block or top drive together with an elevator. A highly accurate
positioning of the tools is necessary in order for the seal of the
tools to locate correctly relative to the pipe section. As far as
possible, mud must be prevented from leaking out onto the drilling
floor, as the mud constitutes a serious health risk for the
personnel located on a rig or drilling vessel. New regulations are
very strict in this respect, and in reality, there is a zero
tolerance of mud spill. The conventional tools are shaped in such a
manner that a correct and quick positioning of the seal is
difficult to achieve, and the tools also tend to jam. Moreover, the
seal is subject to severe wear, so it is not certain whether or not
the seal is in fact tight. In addition, the conventional tools are
relatively large and unmanageable, and may be difficult to adapt to
different equipment having varying dimensions, and they also tend
to leak mud onto the drilling floor when being moved back and forth
across the pipe section.
[0010] The pipe section rising through the drilling floor, to which
the tool is to be connected, often includes an inner threaded
flange to which the next pipe section is to be threadingly
connected. The flange presents an obstruction for the elevator,
requiring the tool with the seal to be lowered a sufficient
distance in order for the seal and the elevator to not be
positioned incorrectly relative to the flange. Due to the manner of
operation of the elevator, the elevator may jam if it is positioned
too close to or contacts the flange. If the seal is not brought
sufficiently far down the pipe section to be fully or in part level
with the flange, the seal between the tool and the pipe section
will be inadequate and may cause leaks and spill onto the drilling
deck.
[0011] Due to the requirement of an automated, unmanned drilling
floor during the installation of casing, the prior art technology
does not accommodate the new remotely controlled, self-gripping
elevators that do not require a flange on the casing sections in
order to lift and lower such casing sections into the well. These
remotely controlled, self-gripping elevators save time as compared
with elevators requiring a flange as they are able to connect to
the casing more quickly since they do not need to locate a flange
on the pipe. The elevator may grip the pipe sections in two
different manners; either the elevator may grip the pipe while the
pipe is located in an essentially horizontal position, or the
elevator may grip vertically arranged pipes provided in an
automated pipe handling system located on the drilling floor. In
either case, there will be a demand to accuracy and verification,
and there is also a need for a flexible adjustment in the
longitudinal direction of a filling and circulating tool, providing
a more rapid and reliable filling and circulation of mud.
[0012] The prior art mud filling and circulation devices are
characterized in that they do not provide adjustability in the
longitudinal direction when the tube or seal is inserted into the
pipe. The prior art devices are fixedly installed in the top drive
and move in the longitudinal direction along with the elevator. The
drawback of these tools is, as mentioned, that they require a very
accurate adaptation to be useful. Such tools are fully mechanical,
and require the tool to be installed in the casing manually by
horizontal arrangement of the elevator before the pipe is raised to
a vertical position to further lower the pipe down onto the
previous pipe section rising through the drilling floor. This is
necessary in order to be able to threadingly connect the pipe
sections using the appropriate torque. It is common to delay
circulation until the pipe section is located approximately one
meter above the drilling deck to be able to manually observe when
the pipe has been filled with mud. In order to effect circulation
using this prior art technology, the casing needs to be suspended
from the drilling floor by slips so that the top drive and the
elevator may be lowered to position a packer inside the casing and
thereby achieve a seal. A major disadvantage of this technology is
that, being mechanically locked to the top drive and moving with
the elevator, it is not able to circulate while the casing is being
lowered into the well. Using a self-gripping automatic elevator, it
is possible, by means of this technology, to initiate the
circulation once the pipe has been wedged to the drilling floor,
after which the self-gripping elevator is lowered an exact
predetermined distance to thereby set the seal of the tool. In
order to achieve circulation while the casing is being lowered into
the well, the seal of the self-gripping elevator must be set while
it gripes the pipe to then lift the pipe up from the slip lock at
the drilling floor, after which the casing is lowered in the
borehole while mud is being circulated. The disadvantage of such a
method is that the process of activating the seal is unreasonably
time consuming and that it is difficult to verify whether or not
the packer has been set and is in fact pressure tight. Another, at
least as important disadvantage, is that the packer needs to be set
approximately 14-18 m above the drilling floor, in which case the
consequence of a leak or a mechanical failure may result in falling
objects or the spreading of hazardous drilling mud from 14-18 m
above the drilling floor. Hence, it has become common practice to
only fill or circulate the casing after the casing has been lowered
into the wellbore and properly locked by the slip lock at the
drilling floor while the pipe project at most approximately 2 meter
above the drilling deck, making it possible to visually observe and
verify that the filling or circulation of mud in the well progress
as expected.
[0013] Another solution also exists comprising a mechanical
adjustment in the longitudinal direction that is able to move the
seal independently of the elevator. This solution allows the seal
to be positioned into the casing independently of the elevator,
making it possible to fill and circulate through the pipe while the
pipe is being lowered into the well. The solution includes a
mechanical telescoping means, the length of which is adjusted by
rotating the top drive, whereby the length increases with the
number of revolutions. When rotating the top drive in the opposite
direction, the tool gets shorter, so that the seal is pulled out of
the pipe. The solution utilizes a two-way hydraulic cylinder,
which, via a pump, is able to apply a pressure that can relocate
the seal independently of the elevator, enabling the filling and
circulation process to proceed while the casing is being lowered
into the well.
[0014] The drawback of the prior art solutions is that they do not
provide any satisfactory indication as to the extent of the length
variations. Hence, the various operations are difficult to verify.
Another major disadvantage is that the movable parts have to
withstand the hydraulic forces caused by the pressure applied to
the seal. The prior art technology suffer from the disadvantage
that no verified support for these forces exist that may be
visually observed at the drilling floor. Thus, there is a huge risk
that a leak may occur 12-14 m above the drilling floor, and of
falling objects, due to the sole mechanical verifications of the
movement and the lack of visual verification. A further
disadvantage of the prior art is that the extension section only
has a limited movement in the longitudinal direction. This
necessitates adaptation of the top drive and the length between the
top drive and the elevator. This causes lost rig time as it is not
possible to use the same length elevator supporting arms as during
drilling. This results in unproductive rig time and additional risk
that objects may fall down onto the drilling floor.
[0015] The above issues have left these prior art technologies with
limited applicability. This is particularly true for floating
drilling units and offshore rigs, for which the safety,
verification, and reliability of the prior art is considered
inadequate and/or too expensive. In practice, telescopic solutions
are not used because they are not considered sufficiently safe. The
authorities have increased the demands upon safety and
verifiability, which has resulted in a need for a tool that is able
to verify that the connection and seal are adequate, and that the
tool automatically prepares for performing the next operational
step in order to save rig time and to provide verification to the
driller at the drilling floor as to the position in which the tool
is located and to which function of the tool is activated at any
time.
[0016] The authorities has increased the demands upon safety and
verifiability, which has resulted in a need for a tool that is able
to verify that the connection and seal are adequate, and that the
tool is ready to perform the next operational step.
[0017] The present invention, according to the independent claim 1,
provides a tool that does not suffer from the above
disadvantages.
[0018] FIG. 1 shows an embodiment of the present invention,
[0019] FIG. 2 shows a section of the embodiment in FIG. 1,
[0020] FIG. 3 shows the head 3 as seen in a bottom view,
[0021] FIGS. 4a-b show the manner in which the present invention
may be lowered into a pipe section for performing filling and/or
circulation,
[0022] FIG. 5 shows how the seal of the present invention is set
for circulation,
[0023] FIG. 6a shows an alternative embodiment of the present
invention in an extended position,
[0024] FIG. 6b shows the embodiment of FIG. 6a along section
B-B,
[0025] FIG. 6c shows the embodiment of FIG. 6b, but in a retracted
position.
[0026] FIG. 1 shows an embodiment of a tool 1 according to the
present invention. Tool 1 includes an elongate, telescopically
acting body 2 comprising a running head 3 at one end of the tool.
Running head 3 includes a valve means 19 that is able to be opened
by outwardly protruding, spring loaded valve arms 5 that are
pressed together when running head 3 is stabbed into a pipe section
6 that rises above a platform deck and forms an upper end of a
pipeline, the valve means 19 assuming a closed position when the
running head is pulled out from pipe section 6 as valve arms 5 are
re-expanded by the spring action. When running head 3 has been
stabbed sufficiently far into pipe section 6, a stopping plate 7
hits the top 8 of pipe section 6. Sensors 9 provided in the
stopping plate 7 will detect that the stopping plate has hit the
top of pipe section 6, and further movement of the tool into pipe
section 6 will be prevented.
[0027] As an alternative, tool 1 may be provided with a
hydraulically actuatible ball valve 19' instead of the outwardly
protruding, spring loaded valve arms 5. When stopping plate 7 hits
the top 8 of pipe section 6, a signal from sensors 9 in stopping
plate 7 will cause the hydraulically actuatible ball valve to open.
An example of such an embodiment is shown in FIGS. 6a-c.
[0028] Tool 1 is fixed to a top drive. When tool 1 is to be
deployed, tool 1 is run, via the top drive, to above the pipe
section 6 rising through the drilling floor. Tool 1 includes a
drive 11 that, through the telescopic action of tool 1, extends
tool 1 so as to run running head 3 down into pipe section 6 until
stopping plate 7 abuts against the top of pipe section 6 and drive
11 receives a signal from sensors 9 in stopping plate 7 informing
that the stopping plate is abutted against the top of the pipe
section and that drive 11 needs to stop the telescopic movement.
This is shown in FIGS. 4a-c.
[0029] At this point, tool 1 is correctly positioned in pipe
section 6, and valve means 19, 19' has opened due to the fold-in of
valve arms 5 on insertion of running head 3 into pipe section 6 or
to activation of the hydraulically actuatible ball valve.
[0030] Running head 3 also includes two metal rings 12, 13 as well
as a sealing element 14. By squeezing sealing element 14 between
metal rings 12, 13, the sealing element will expand outwards and
seal against the interior of pipe section 6. The radii of metal
rings 12, 13 and sealing elements 14 are chosen so that sealing
element 14 does not project outside metal rings 12, 13 when the
metal rings are not squeezed together. In this manner sealing
element 14 is protected when tool 1 is being run into or out of
pipe section 6. If tool 1 scrapes or hits against the inner walls
of pipe section 6, sealing element 14 will be protected against
wear and tear as metal rings 12, 13 take the load. Preferably,
metal rings 12, 13 are shaped having sloping edges in order to
facilitate the process of running tool 1 into or out of pipe
section 6 without the risk of hooking onto something or undue
scraping against the inner walls of pipe section 6. As mentioned,
sealing element 14 is set by squeezing metal rings 12, 13 together.
This action may be achieved, for example, in that running head 3 is
fully telescopically retracted by drive 11 or another drive means
adapted for the purpose. This is shown in FIG. 5.
[0031] During filling of pipe section 6, it will not be necessary
to set sealing element 14, but during circulation, sealing element
14 will have to be set in order to secure the seal against the
inner walls of pipe section 6.
[0032] Due to the shape and manner of operation of tool 1, various
verifiable feedbacks are provided to the operator during the
operation of the tool. The positioning of valve arms 5 indicates
whether or not the valve of running head 3 is open. Sensors 9 in
stopping plate 7 provide feedback as to whether tool 1 runs
sufficiently far into pipe section 6. Drive 11, by means of
suitable locking mechanisms and sensors, may confirm that tool 1
has been locked in its correct extended position and does not run
the risk of being pushed out of pipe section 6 in the case of a
sudden, severe pressure buildup in the well. Also, the status of
seal 12 may be verified by sensors indicating whether or not
running head 3 has been telescopically retracted by drive 9 or
another similar drive means. While the present invention has been
explained with reference to an embodiment including a stopping
plate 7, sensors 9 detecting that the tool has been run a certain
length into the pipe section could have been used to achieve the
same result. The signal from sensor 9, detecting how far into the
pipe section the tool has been run, is used both to automatically
stop further lowering of the tool and to verify for the operator
that the tool is in fact correctly positioned in the pipe section,
so that the next operation step may commence. Thus, the signal from
sensor 9 will result in a go-ahead signal on the operator panel if
the operation proceeds normally, or alternatively an error signal
that both indicates an error and prevents further work.
[0033] The distance A (see FIG. 1) with which running head 3
extends into pipe section 6 may be adjusted by moving stopping
plate 7 up or down along tool 1. This may be accomplished, for
example, by providing stopping plate 7 and tool 1 with threads,
whereby stopping plate 7 is moved up or down when being rotated
relative to the tool. As an alternative, as mentioned, a number of
sensors 9 are used instead that indicate how far into the pipe
section running head 3 extends. Different applications, pipe types,
or the fact that the elevator grips each pipe section at a slightly
different point, will require that the distance from running head 3
to stopping plate 7 and/or sensors 9 is adjusted each time, as this
distance determines how far into pipe section 6 the running head
extends.
[0034] According to an embodiment of the present invention, tool 1
is provided with means in the form of sensors or the like measuring
the distance from the gripping point of the elevator to the pipe
section end. This distance influences how far running head 3 is to
be run into the pipe section. If the distance from the gripping
point of the elevator to the pipe section end is measured, this
measurement is used by the operator or an automatic control system
to subsequently run running head 3 the appropriate length into the
pipe section. Several known sensors are commercially available that
may be adapted for this particular application.
[0035] According to an embodiment of the present invention, drive
11 comprises a pitch rack 15 and one or more gear wheels 16. By
rotating gear wheel 16, running head 3 is run either into or out of
pipe section 6. Drive 11 receives a signal from sensor(s) 9, which
signal causes the drive 11 to stop when running head 3 has been run
sufficiently far into the pipe section.
[0036] According to another embodiment of the present invention,
drive 11 comprises a hydraulically actuated telescoping device that
operates to extend and retract the telescopically acting body 2
comprising a running head 3. It is understood that other drive
means may be used in order to move running head 3 into and out of
the pipe section, such as pneumatically or electrically actuated
systems, etc.
[0037] According to an embodiment of the present invention, tool 1
also includes a locking block or locking pal 17, as well as a
ratchet lever 18, the locking pal 17 being engaged with ratchet
lever 18 in order to make sure running head 3 maintains the correct
position in pipe section 6. Ratchet lever 18 and locking pal 17 may
be shaped in such a manner that their mutual engagement may not
loosen and cause impact movement in the case of strong vertically
upward forces acting on the tool from the well. A sensor may
confirm that locking pal 17 has correctly engaged ratchet lever 18.
Various other locking mechanisms preventing impact movement of the
tool may also be used.
[0038] According to another embodiment of the present invention,
tool 1 includes slips 23 that assist in ensuring that running head
3 maintains the correct position in pipe section 6. In one
embodiment, slips 23 may be disposed on the running head below
stopping plate 7, and be shaped in such a manner that teeth or jaws
are forced out to engage the interior of pipeline 6. Slips 23 are
of a "non marking" type, that is, minimizes the imprint onto the
interior of the pipeline.
[0039] According to an embodiment of the present invention, tool 1
also includes a sensor at the end of running head 3 that detects
the level of liquid in the pipeline into which it is inserted. The
detection of the liquid level will help enabling a significant
increase of the mud filling rate. Today, the filling rate is kept
down in order to avoid the risk of overfilling pipeline 6, causing
mud to squirt out onto the drilling floor. Using a liquid level
detector, the filling may be performed automatically and with an
increased filling rate. This will save time and facilitate/provide
verification. The liquid level detector will be able to send a
signal to the control system of the tool and to the operator panel.
Several known liquid level detectors are commercially available,
that may be adapted to this particular use.
[0040] In the following, exemplary advantageous functions of tool 1
are provided.
Filling
[0041] In filling a pipe section 6, for example, an elevator is
used for gripping and lifting a casing section, after which this
pipe section is connected to the pipeline that has been lowered
into a well, and the one end of which rises through the platform
deck. Tool 1 is located above pipe section 6 and is mounted in the
top drive. Regardless of the type of elevator or pipe lifting means
that is being used, such as a side door elevator, slip joint
elevator, etc., the operation of tool 1 will be the same. The
distance from the gripping point of the elevator to the pipe
section end is measured, providing indication to the system of how
far into the pipe section running head 3 is to be run.
[0042] Drive 11 of tool 1 is activated so that running head 3,
being arranged on the elongate, telescopically acting body 2, is
caused to move downwards in an outgoing impact movement making the
valve arms 5 hit the top of pipe section 1 and hence fold inwards
(see FIGS. 4a-4c).
[0043] The outgoing impact movement proceeds continuously until
stopping plate 7 hits the top of pipe section 6, or sensors 9
detect that the running head has been run sufficiently far into
pipe section 6. The optional stopping plate 7 is provided with a
sensor array or sensors 9 detecting that stopping plate 7 has hit
the top of pipe section 6. Alternatively, only sensors 9 are used.
Sensors 9 send a stop signal to drive 11. The distance from
stopping plate 7 to running head 3 determines how far running head
3 extends into pipe section 6. As mentioned, this distance may be
adjusted by moving stopping plate 7 closer to or further away from
running head 3.
[0044] Then locking pal 17 is locked to engage ratchet level 18.
Alternatively, if slips 23 are used instead of the locking
pal/ratchet lever pair, the slips are activated. This ensures that
the elongate, telescopically acting body 2 with running head 3 does
not hit upwards out of pipe section 6 due to a pressure buildup in
the well.
[0045] When valve arms 5 hit the top of pipe section 1 and fold
inwards, a valve means 19 is opened. This valve may, for example,
be comprised of a disc valve 20 that in a closed position abuts
against a valve seat 21. Alternatively, the hydraulic ball valve
19' is activated when the stopping plate hits the top of pipeline
6. When valve means 19, 19' opens, fluid may flow through tool 1,
valve 19, 19', and exit through a liquid outlet 4 provided in the
running head. In that, pipe section 6 is filled with fluid.
[0046] The liquid level detector monitors the level of liquid in
the pipe section as it fills, thereby acting to prevent the liquid
level in the pipe section from becoming too high.
[0047] When the process of filling pipe section 6 has been
completed, locking pal 17 or slips 23 are deactivated, and drive 11
is activated to carry out a retracting impact movement pulling the
elongate, telescopically acting body 2 out of pipe section 6. When
running head 3 has been pulled sufficiently far out of pipe section
6 for the valve arms 5 to spread out, valve means 19 is closed.
Alternatively, hydraulic ball valve 19' is actuated to close. Any
fluid remaining in running head 3 may continue to flow out of the
running head and down into pipe section 6 until it has been
completely emptied. This prevents subsequent spill onto the
platform deck.
[0048] The retracting impact movement of the elongate,
telescopically acting body 2 comprising running head 3 continues
until tool 1 is located a sufficient distance above pipe section
end 8, after which the operation may be repeated. Optionally, tool
1 may be moved and parked at a desired place.
Circulation
[0049] During circulation of fluid through the well, the manner of
operation of tool 1 is somewhat different than during a filling
operation.
[0050] In a similar manner as in the filling operation, the drive
of tool 1 is activated so that running head 3, being arranged on
the elongate, telescopically acting body 2, is caused to move
downwards in an outgoing impact movement making valve arms 5 hit
the top of pipe section 1 and hence fold inwards. Valve arms 5 hit
the top of pipe section 1, fold inwards, and cause valve means 19
to open.
[0051] The outgoing impact movement proceeds continuously until
stopping plate 7 hits the top of pipe section 6, and/or until
sensor(s) 9 send a stop signal to drive 11 informing that running
head 3 extends sufficiently far into pipe section 6 (se FIGS.
4a-4c).
[0052] Alternatively, the hydraulic ball valve 19' is activated to
open when stopping plate 7 hits the top of pipeline 6.
[0053] Again, locking pal 17 is activated to engage ratchet lever
18. Alternatively, slips 23 are activated to engage the inner walls
of pipeline 6. This ensures that the elongate, telescopically
acting body 2 comprising running head 3 does not hit upwards out of
pipe section 6 in case of a pressure buildup in the well.
[0054] Then sealing element 14 is activated to make the tool 1 seal
against the inner walls of pipe section 6 by squeezing metal rings
12, 13 together, whereby sealing element 14 expands outwards and
seals against the inner walls of pipe section 6 (see FIG. 5). As
mentioned, the diameter of metal rings 12, 13 and sealing element
14 are selected so that sealing element 14 does not project outside
metal rings 12, 13 when they are not squeezed together. In this
manner, sealing element 14 is protected when tool 1 is run into or
out of pipe section 6.
[0055] If tool 1 scrapes or hits against the interior of pipe
section 6, sealing element 14 will be protected against wear and
tear as metal rings 12, 13 take the load. Preferably, metal rings
12, 13 are shaped having sloping edges in order to ease the process
of running tool 1 into or out of pipe section 6 without the risk of
hooking onto something or undue scraping against the inner walls of
pipe section 6. As mentioned, sealing element 14 is activated by
squeezing metal rings 12, 13 together. This action may be achieved,
for example, in that running head 3 is fully telescopically
retracted by drive 11 or another drive means adapted for the
purpose. FIGS. 1 and 2 show an embodiment using a separate drive
for squeezing metal rings 12, 13 together, thereby expanding
sealing element 14 outwards to seal against the interior of pipe
section 6. According to this embodiment, the drive is a hydraulic
drive.
[0056] When the tool 1 has been correctly positioned into pipe
section 6 and sealing element 14 has been activated by squeezing
metal rings 12, 13 together, the circulation through the downhole
pipeline may be carried out for as long as desired. When the
circulation operation is to be ended, the pumps circulating the
fluid through tool 1 and the downhole pipeline are stopped, and
sealing element 14 is unset in that the hydraulic drive pulls metal
rings 12, 13 apart, whereby sealing element 14 assumes its original
shape. The locking pal 17 or slips 23 for preventing undesired
impact movement are released, and drive 11 is caused to retract the
elongate, telescopically acting body 2 comprising running head 3 in
a retracting impact movement, whereby valve arms 5 expands and
close valve means 19 when the running head exits pipe section
6.
[0057] During backflow through the downhole pipeline the manner of
operation of the tool is the same as during circulation, except
that the fluid is drawn up through the pipeline and the tool.
[0058] According to an embodiment of the present invention, tool 1
includes an electronic signal control module receiving, processing,
and communicating signals from the sensors and drives of tool 1,
wherein the electronic signal control module of tool 1
communicates, wirelessly or not, with an electronic signal control
module at the drilling floor, said two electronic signal control
modules being designed to cooperate in performing the tasks of tool
1, wherein the electronic signal control module of tool 1, on the
receipt of a particular signal from the electronic signal control
module at the drilling floor, causes tool 1, by means of
measurements of the distance from the gripping point of the
elevator on the pipeline 6 to the pipeline end 8, measurements from
sensors 9, and optionally also by means of measurements of the
level of liquid in the pipeline 6, to find an optimal position for
running head 3 relative to pipeline 6, the position corresponding
to one of the following positions: [0059] a) a standby position if
filling, emptying, or circulation is not to be performed, [0060] b)
a filling position, [0061] c) an emptying position, or [0062] d) a
circulating position, the current position and the various
measurements being continuously updated and mediated to the
electronic signal control module at the drilling floor, so that the
operation and state of tool 1 may be monitored and verified at any
time by the electronic signal control module at the drilling floor
and/or an operator.
[0063] An important feature of the tool according to the present
invention is that each operational step performed thereof is
verifiable. When stopping plate 7 and/or sensors 9 detect that
running head 3 has been run sufficiently far into pipe section 6, a
signal is sent to drive 11 and to the operator panel, informing the
operator on how far into pipe section 6 running head 3 is located.
At the same time, the operator will know for sure that valve means
19 has opened because valve arms 5 are forced to fold together to
open valve means 19 before running head 3 may be run further down
pipe section 6. As an alternative, the hydraulic ball valve 19' may
only be activated after the top plate 7 has hit the top of pipeline
6 and this being confirmed by sensors 9. The independently
controlled locking mechanism 17, 18, or slips 23, will, in a
verifiable manner, indicate that the elongate, telescopically
acting body 2 has been locked in the extended position, as locking
mechanism 17, 18 or slips 23 are shaped in such a manner that it
may not slip and strike up if tool 1 is subject to an upward force.
The verification from the "active" sealing element 14 that the seal
has been set is provided in that the drive must be activated in
order for metal rings 12, 13 to squeeze together to expand sealing
element 14. Also, the means measuring the distance from the
gripping point of the elevator on pipeline 6 to pipeline end 8, and
the means measuring the liquid level in pipeline 6, enables the
operator to monitor and verify that the elevator has actually
gripped pipeline (6) as well as the level of mud in the pipeline
(6).
* * * * *