U.S. patent application number 12/679254 was filed with the patent office on 2011-06-02 for method of abandoning a petroleum well.
This patent application is currently assigned to Ziebel AS. Invention is credited to Henning Hansen, Kaj Stokkeland, Terje Wilberg.
Application Number | 20110127035 12/679254 |
Document ID | / |
Family ID | 40468112 |
Filed Date | 2011-06-02 |
United States Patent
Application |
20110127035 |
Kind Code |
A1 |
Hansen; Henning ; et
al. |
June 2, 2011 |
METHOD OF ABANDONING A PETROLEUM WELL
Abstract
The present invention relates to a method of abandoning a
petroleum well (1) which is provided with at least one measuring
device (21) which by means of a communication means (9, 23) is
arranged to be able to communicate measured results to a receiver
device (29) located at a surface (5) of the well (1), where the
method comprises to terminate the communication means (9, 23) in a
first communication coupling (91') located in a portion of the well
(1) above an upper well barrier (11) so that the receiver device
(29) being supplied with a fourth communication coupling (94')
which complementary fits with said first communication coupling
(91'), may selectively be connected to or disconnected from the
measuring device (21) for communication of data out from the well
(1).
Inventors: |
Hansen; Henning; (Dolores
Alicante, ES) ; Wilberg; Terje; (Vollen, NO) ;
Stokkeland; Kaj; (Sirevag, NO) |
Assignee: |
Ziebel AS
|
Family ID: |
40468112 |
Appl. No.: |
12/679254 |
Filed: |
September 18, 2008 |
PCT Filed: |
September 18, 2008 |
PCT NO: |
PCT/NO2008/000336 |
371 Date: |
August 30, 2010 |
Current U.S.
Class: |
166/297 |
Current CPC
Class: |
E21B 47/12 20130101;
E21B 33/13 20130101 |
Class at
Publication: |
166/297 |
International
Class: |
E21B 29/00 20060101
E21B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 20, 2007 |
NO |
20074796 |
Claims
1. A method of abandoning a petroleum well and maintaining
communication of the well after cutting a casing, where a well pipe
that is located within the casing is provided with a communication
means that extends between at least one measuring device and a
receiver device being located at a surface of the well
characterized in that the method comprises the steps of:
disconnecting an upper section of the well pipe from a lower
section of the well pipe and removing the upper section from the
cut location while the cutting of the casing is in progress such
that the well pipe is not damaged; reintroducing said upper section
into the well and connecting the upper section to said lower
section; terminating the communication means in a first
communication coupling located in the upper section of the well
pipe, the communication coupling being selectively connectable to
or disconnectable from the measuring device for communication of
data out from the well.
2. The method according to claim 1, characterized in that the
communication means is constituted by a signal transmission cable
extending on an outside of the well pipe.
3. (canceled)
4. The method according to claim 1, characterized in that the
communication means is constituted by the well pipe itself.
5. (canceled)
6. The method according to claim 1, characterized in that the
communication means is connected between the upper section of the
well pipe and the lower section of the well pipe by means of a
second communication coupling, respectively a third communication
coupling.
7. The method according to claim 1, characterized in that the
method further comprises supplying an upper end portion of the
upper section of the well pipe with a first coupling device making
possible selective connection or disconnection of the receiver
device or other equipment or pipe being provided with a fourth
coupling device complementary fitting with said first coupling
device, said first coupling device being located in a portion of
the well located above a settable upper barrier.
8. The method according to claim 7, characterized in that the
method further comprises supplying the upper section of the well
pipe with a second coupling device being located in a lower end
portion of said upper section, so that the upper section of the
well pipe is defined by the first coupling device and the second
coupling device, and that the method further comprises supplying an
upper end portion of the lower section of the well pipe with a
third coupling device.
9. The method according to claim 1, characterized in that the
method further comprises integrating relevant communication
couplings in the coupling devices.
10-15. (canceled)
Description
[0001] The present invention relates to a method of abandoning a
petroleum well. More particularly it concerns a method of
abandoning a petroleum well which is provided with at least one
measuring device arranged for communicating measuring results to a
receiver device by means of a communication means extending between
the measuring device in the well and the receiver device located at
a surface of the well.
[0002] In connection with search and exploration for and possible
production from hydrocarbon reservoirs under the earth surface,
petroleum wells are drilled. When some of, or all the mentioned
activities are completed, a petroleum well, hereinafter called
"well" may be abandoned.
[0003] To be able to abandon a well there are requirements
regarding protection of the well against fluid leaks through the
well and up to the surface. Such protection of a well may be
temporary or permanent. A person skilled in the art will know which
barriers are required for a temporarily protected well and for a
permanently protected well.
[0004] Even if a well is abandoned, it will be of great value to be
able to perform measurements in the well and in the reservoir. This
is to be able to collect information on possible changes in such as
pressure and temperature in the well and the reservoir. Such
measurements can give valuable information about such as stabilised
temperature in the reservoir and from reservoir to the sea bed,
development regarding pressure in the reservoir, so-called pressure
communication with another well or other wells in the area,
distances to geologic faults in the underground and extension of an
area with producible hydrocarbon volumes.
[0005] Additionally it might be useful to collect information about
pressure across barriers in the well and thereby obtaining
knowledge about the barrier integrity. Such barriers may for
example be, but are not limited to, mechanical plugs, cemented
sections, chemical products and gravel pack materials. By the
notion cemented in this context is meant a seal obtained by a
liquid seal material filling a space and then transforming to the
solid state.
[0006] For safety reasons authorities, among others, require that a
protected well has several, independent barriers.
[0007] A well comprises typically a composite casing where more
casings having different diameters are located one inside the
other. Well piping is installed in the casing as needed. Examples
of such well piping are drill pipe and production tubing.
[0008] A single casing or a composite casing, which may also
comprise other piping such as liner, are below called casing. The
casing typically extends down into the ground from a wellhead,
which as a submerged well is concerned is located above the
seabed.
[0009] According to prior art a well in the ground is permanently
protected by removing the upper portion of the well. This is done
by a rig vessel, which firstly is brought in over the well and
pulls at least a portion of the production piping out of the well.
The casing is thereafter cut below the sea-bed by means of a
cutting tool. After the casing has been cut, the cutting tool is
removed from the well whereafter the rig vessel lifting equipment
is connected to the casing and lifts the upper cut casing portion
out of the well.
[0010] s The method according to prior art calls for the
utilisation of relatively large vessels equipped with drilling
equipment, and these are, among other things, due to repeated
connection to the well, relatively time consuming and costly.
[0011] Another considerable drawback with prior art cutting of the
casing is that, in addition to the casing itself, any cable also
running inside the casing will also be cut. Communication via a
cable such as a signal transmission cable or a well pipe, between
for example a sensor in the well and a receiver device located
above the cut location, will thus not be possible after cutting of
the casing. A person with knowledge in the art will be familiar
with that the alternative to communication via cable, so-called
wireless communication, has a limited range. Wireless communication
will in most cases thus not be suitable for wells stretching far,
for example 2000 m into the earths crust.
[0012] The object of the invention is to remedy or reduce at least
one of prior art drawbacks.
[0013] The object is achieved by features given in the below
description and in the following Claims.
[0014] The present invention relates to a method of abandoning a
petroleum well which is provided with at least one measuring device
by means of which a communication means is provided to be able to
communicate measured results to a receiver device located at a
surface of the well, where the method comprises termination of the
communication means in a first communication coupling located in a
portion of the well above an upper well barrier, so that the
receiver device being provided with a fourth communication coupling
which complementary fits with said first communication coupling,
may selectively be connected to or disconnected from the measuring
device for communication of data out from the well.
[0015] In one embodiment the communication means is constituted by
a signal transmission cable or "lead".
[0016] In one embodiment the communication means is constituted by
a well pipe where data or measured results from the measuring
device are transmitted through the well pipe, for example by means
of sound waves. A person with knowledge in the art will appreciate
that the signals from the measuring device then need to be
transferred to the well pipe by means of a sound wave generating
device and that the receiver device need to be arranged to be able
to intercept the sound waves transmitted through the well pipe
material.
[0017] Further features of the method according to the present
invention are given in the following description and in the Claims
3 and 5-15.
[0018] The at least one measuring device may be provided by a
single or more spaced measuring devices such as sensors, or it may
be provided by such as a fibre optical cable or semi rigid rod of
the type described in Norwegian Patent Application NO 20065913
handed in by the present applicant and which is incorporated in
this document by reference.
[0019] In those cases where the communication means are provided by
a signal transmission cable or lead, the signal transmission cable
extending between the at least one sensor and the terminal point is
located to a well pipe located in the well. The well pipe may be,
but is not limited to, such as a production tubing.
[0020] Advantageously, the signal transmission cable and any other
leads or cables are, at least partly, placed in an enclosure
attached to or integrated in the well pipe. The enclosure will
inter alia be able to reduce the risk of fluid leaking through a
barrier, where the barrier is provided by means of a fluid
transforming to solid state. A cement plug is an example of such a
barrier. Leaks may occur in such barriers due to insufficient
packing of the barrier between lead(s) and well piping.
[0021] In the following is described an example of a preferred
embodiment illustrated in the attached drawings, where:
[0022] FIG. 1 shows a well where several casings extend from a
wellhead at the surface and where a well pipe provided with
settable packers is led into the well;
[0023] FIG. 2 shows a temporarily abandoned well where the well
pipe is terminated in the well and where settable packers and
internal well barriers are set;
[0024] FIG. 3 shows the same as FIG. 2, but where a measuring
device in the form of a data logger is connected to an upper
portion of the well pipe in order to be able to receive, via a
signal transmission cable or lead placed on the outside of the well
pipe, signals or data from sensors located in the well;
[0025] FIG. 4 shows the well in FIG. 2, but where a cementing pipe
is connected to the upper portion of the well pipe and where the
internal top well barrier has been removed and a sealing substance
is circulated into a lower portion of the well by means of a lower
circulation valve;
[0026] FIG. 5 shows the well in FIG. 4, but where sealing substance
is placed in three zones in the well and where the cementing pipe
and an upper portion of the well pipe is disconnected and removed
from a lower portion of the well pipe;
[0027] FIG. 6 shows the well in FIG. 5, but where a part of the
wellhead is removed; whereafter recesses are formed in the inner
casing and where sealing substance is introduced in a portion of
the annulus between the two innermost casings;
[0028] FIG. 7 shows the well in FIG. 6, but where the whole
wellhead is removed and the casings cut below the seabed, after
which the upper well pipe section once more is connected to the
lower well pipe section; and
[0029] FIG. 8 shows the well in FIG. 7, but where a data logger is
situated at an end portion of the upper well pipe section.
[0030] In the figures, that a person with knowledge in the art will
appreciate are only principle sketches, the reference numeral, 1
relates to a well lined with several casings 3 placed one inside
the other. The casings 3 extend from a surface 5 being such as a
seabed. A wellhead 7 is placed on the seabed 5 over the casings
3.
[0031] A well pipe 9 is placed in the well 1. In the example of the
embodiment shown, the well pipe is a production tubing.
[0032] The well pipe 9 includes an upper barrier 11 and a lower
barrier 13 where both may be set to seal an annulus between the
well pipe 9 and the innermost casing 3. This annulus is known as
the "A-annulus". The settable barriers or packers 11, 13 may be
activated/deactivated in a way known per se.
[0033] The well pipe 9 is further provided with an upper
circulation valve 15 and a lower circulation valve 17 arranged to
be able to circulate a sealing substance 19 (see FIG. 5) into the
well 1 to provide a so-called permanent barrier in the annulus
between the well pipe 9 and the casing 3 and internally in the well
pipe 9.
[0034] The well pipe 9 further consists of an upper well pipe
section 9a and a lower well pipe section 9b. The upper well pipe
section 9b is defined by a first coupling device 91 and a second
coupling device 92 located in an upper and a lower end portion
respectively of the upper well pipe section 9a. The second coupling
device 92 is arranged to be able to be connected to a complementary
fitting third coupling device 93 positioned in an upper end portion
of the lower well pipe section 9b. Correspondingly, the first
coupling device 91 is arranged to be able to be connected to a pipe
or other equipment provided with a complementary fitting fourth
coupling device 94. In the figures the first and the second
coupling devices 91, 92 are shown as so-called female or box
connectors, while the third and fourth coupling devices 93, 94 are
shown as so-called male or pin connectors. Which of the connectors
91, 92, 93, 94 being pin connectors and which are box connectors is
of no significance for the invention as long as said connectors fit
complementary together.
[0035] The coupling devices 91, 92, 93, 94 are controlled in a way
known per se by means of for example, but not limited to,
electricity or hydraulics. Advantageously the coupling devices are
made with arrangements (not shown) making connection to for example
a lifting tool (not shown) possible.
[0036] On the outside of the well pipe 9 are placed two measuring
devices or sensors 21, one at the top of the lower barrier 13 and
one at the top of the upper barrier 11. The sensors 21 are
connected to a signal transmission cable or lead 23 running along
the outside of the well pipe 9. The leads 23 are allocated to
communication connectors or contacts 91', 92' and 93' placed in the
coupling devices 91, 92 and 93 respectively. Depending on the
function of the pipe or equipment of the fourth coupling device 94,
this may be provided with a communication connector or contact 94'.
A receiver device 29 would for example have to be provided with a
contact 94' placed in the coupling device 94 if it shall be able to
be connected to the lead 23 ending in the contact 91' placed in the
first coupling device 91.
[0037] For the sake of clarity, the reference numerals for the
contact devices 91', 92', 93' and 94' are only given in FIG. 1.
[0038] Portions of the well pipe 9, above the circulation valves
15, 17, are provided with cable ducts 25 arranged to be able to
receive such as the lead 23 and any other cables (not shown). The
cable ducts 25 reduce the risk of fluid leaks up through the
interface area between the lead 23 and any other cables and the
well pipe 9. Experience shows that that it is very difficult to
achieve adequate packing of sealing substance 19, such as concrete,
in this area. The cable ducts 25 are made with transition without
acute angle against the outer surface of the well pipe 9.
Preferably the cable ducts 25 are filled inside with a suitable
sealing substance (not shown) after the lead 23 and possibly any
other leads are pulled through.
[0039] The well pipe 9 is also provided with a so-called
centraliser unit 12 which design and function will be known to a
person with knowledge in the art and which for that reason is not
discussed further in this document. Further details of the well
pipe shown, but not given reference numerals or closer description
in this document, will also be well known to a person with
knowledge in the art.
[0040] In FIG. 1 is shown an open well 1 wherein the upper well
pipe section 9a of the well pipe 9 is connected to a connecting
pipe 9c by means of the first 91 and fourth 94 coupling device. The
connecting pipe 9c extends up through the well-head 7 and for
example a rig (not shown) on a sea surface (not shown).
[0041] In FIG. 2 the well is temporarily abandoned. The upper
barrier 11 and the lower barrier 13 are set such that a portion of
the annulus between the lower well pipe section 9b and the casing
3, the so-called "A-annulus", is isolated. Internal flow within the
well pipe 9 is prevented by means of internal barriers or packers
27. The internal packers 27 are of a type known per se and are
therefore not discussed further in this document. The connecting
pipe 9c shown in FIG. 1 is disconnected from and removed from the
upper well pipe section 9a.
[0042] In FIG. 3 a logging unit 29 is connected to the upper well
pipe section 9a by means of the first coupling device 91 and a
coupling device 94 corresponding to the coupling device 94 for the
connecting pipe 9c shown in FIG. 1.
[0043] The logging unit 29 is arranged to be able to receive and
store signals from the sensors 21. The signals are led to the
logging unit 29 through the leads 23. The logging unit 29 may
possibly transmit data to a vessel on the surface (not shown) by
means of for example a cable (not shown). Alternatively the data
may be stored in the logging unit 29 and be brought out at a later
time when the logging unit is brought up to for example a vessel
(not shown).
[0044] The logging unit 29 is brought to and from the well 1 for
example by means of a lifting tool (not shown). The logging unit 29
has a size and a weight making handling by a small vessel
possible.
[0045] FIG. 4 shows a step in the process of preparing the well 1
to be abandoned permanently. A cementing pipe 9c' is connected to
the upper section 9a of the well pipe 9 in a way which corresponds
to the connecting pipe 9c or the logging unit 29 discussed above.
Following removal of the inside barrier 27 in the well pipe 9, a
sealing substance 19 is circulated into the lower portion of the
well 1 by means of the lower circulation valve 17. The objective of
the sealing substance 19 is to provide a first permanent barrier.
The sealing substance 19 may be of any suitable material, which
after placement is transformed from fluid state to solid state.
So-called "cement" is an example of such a suitable medium.
[0046] At the same time as the sealing substance 19 is circulated
in the well 1, fluid present in the well 1 is displaced by the
sealing substance 19. To achieve a controlled displacement of fluid
present in the well 1, the upper barrier 11 is provided with an
evacuation valve 31 arranged to be controlled between open and
closed positions. The evacuation valve 31 is for example, but not
limited to, electrically or hydraulically controlled. The valve
control system is of a type known per se and is therefore not shown
in the drawings. A person with knowledge in the art will appreciate
that the valve needs to be controlled between closed and open
positions, and that a check valve is not suitable for this
purpose.
[0047] FIG. 5 shows the well following the provision of two more
barriers that are provided by means of sealing substance being led
into portions of the well 1. The barriers are placed in portions
both inside in the lower well pipe section 9b and in the A-annulus
between the lower well pipe section 9b and the casing 3.
[0048] Cementing pipe 9c' shown in FIG. 4 and the upper well pipe
section 9a are pulled out of the well 1 by in the least that the
second coupling device 92 (see FIG. 4) and the third coupling
device 93 are disconnected from each other.
[0049] The upper well pipe section 9a is pulled out of the well to
be able to make room for a cutting or hole making tool (not shown)
which is arranged to be able to provide openings 34 in one or more
of the casings 3 so that sealing substance may be squeezed into a
portion of the annulus 33 defined between two casings 3. This is
shown accomplished in FIG. 6, where the well is to be regarded as
permanently abandoned. The annulus 33 between the two innermost
casings 3 is known as the B-annulus.
[0050] The third coupling device 93 placed in an upper end portion
of the lower well pipe section 9b is in FIG. 6 shown protected by a
cap 95. Preferably, the cap 95 is placed over the coupling device
93 before the operation of making holes in the casing 3 is carried
out and is preferably not removed before sealing substance 19 is
filled into a portion of the annulus between the casings 3.
[0051] In FIG. 7 the wellhead is removed and the casings 3 are cut
below the seabed 5. The casings 3 are cut typically 5-6 m below the
seabed 5.
[0052] Following removal of the cap 95 shown in FIG. 6, the upper
well pipe section 9a is again, in FIG. 7, connected to the lower
well pipe section 9b by means of the coupling devices 92, 93. The
cap 95 protects the upper end portion of the upper well pipe
9a.
[0053] The well 1 is in FIG. 7 protected by means of both the
settable barriers 11, 13 and the permanent barrier provided by the
sealing substance 19.
[0054] It is to be noted that in an alternative embodiment (not
shown), sealing substance 19 such as cement is also supplied to the
annulus defined between the upper well pipe section 9a and the
casing 3 after the upper well pipe section 9a is connected to the
lower well pipe section 9b. In this alternative solution, the upper
well pipe section 9a will be cast fixated to the well 1. It is to
be understood that the sealing substance must not be filled higher
up than to the lower edge of the first coupling device 91 if this
shall be utilised in the future.
[0055] While FIG. 3 shows a logging unit 29 connected to a
temporarily abandoned well 1, FIG. 8 shows the same logging unit 29
connected to a permanently abandoned well 1. Well data may thus be
collected from a permanently protected well 1.
[0056] In those cases where the well pipe 9, instead of the lead or
the signal transmission cable 23, is utilised as communication
means to transmit measured results or data from the measuring
device(s) 21 in the well to the receiver device 29, the method will
be the same as described above.
[0057] The present invention thus provides for possibilities to
collect information about any development in the well whether it is
in operation, is temporarily abandoned or permanently
abandoned.
[0058] By the very fact that the lower well pipe section 9b is left
in the well 1, the operation may be carried out by means of
relatively small vessels (not shown). This will among other things
imply reduced cost at the same time as a better permanently
protected well is obtained.
* * * * *