U.S. patent application number 13/124471 was filed with the patent office on 2012-01-05 for apparatus and methods for improved cement plug placement.
Invention is credited to Gerard Daccord, Simon James, Michael Montgomery, Bernard Piot, Radovan Rolovic, Joel Rondeau, Mathew Samuel.
Application Number | 20120000649 13/124471 |
Document ID | / |
Family ID | 40380186 |
Filed Date | 2012-01-05 |
United States Patent
Application |
20120000649 |
Kind Code |
A1 |
James; Simon ; et
al. |
January 5, 2012 |
APPARATUS AND METHODS FOR IMPROVED CEMENT PLUG PLACEMENT
Abstract
A method and apparatus for making real-time measurements of
downhole properties during cement plug placement. A wired placement
conduit (30) is lowered downhole releasing a sensor package (34).
The sensor package is capable of measuring downhole properties in
real-time in the period while cement plug sets.
Inventors: |
James; Simon; (Le Plessis
Robinson, FR) ; Piot; Bernard; (Paris, FR) ;
Rondeau; Joel; (Antony, FR) ; Montgomery;
Michael; (Sugar Land, TX) ; Daccord; Gerard;
(Vauhallan, FR) ; Rolovic; Radovan; (Sugar Land,
TX) ; Samuel; Mathew; (Sugar Land, TX) |
Family ID: |
40380186 |
Appl. No.: |
13/124471 |
Filed: |
September 30, 2009 |
PCT Filed: |
September 30, 2009 |
PCT NO: |
PCT/EP2009/007061 |
371 Date: |
June 21, 2011 |
Current U.S.
Class: |
166/250.04 ;
166/192; 166/386 |
Current CPC
Class: |
E21B 33/13 20130101;
E21B 47/005 20200501; E21B 47/08 20130101; E21B 47/06 20130101 |
Class at
Publication: |
166/250.04 ;
166/192; 166/386 |
International
Class: |
E21B 47/09 20060101
E21B047/09; E21B 33/12 20060101 E21B033/12 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2008 |
EP |
08167050.7 |
Claims
1. Apparatus for placing a cement plug in a well, comprising: a
pipe for delivering a cement slurry to a predetermined location in
the well to be plugged; at least one sensor located at a lower end
of the pipe and operable to measure parameters in the well at the
predetermined location; and an operating system located at the
surface for receiving output signals from the sensor; wherein the
sensor is configured to measure at least one parameter relevant to
cement plug placement and is connected to the operating system by
means of a cable. wherein the sensor performs a caliper measurement
for indicating hole diameter as the pipe is run into the well.
2. Apparatus as claimed in claim 1, wherein the sensor comprises a
differential pressure sensor.
3. Apparatus as claimed in claim 1, wherein the sensor comprises a
temperature sensor.
4. A method of placing a cement plug in a well, comprising:
providing a pipe for delivery of the cement plug with a sensor at
its end; introducing the pipe into the well such that its end is at
a predetermined location for placement of the plug; operating the
sensor to measure at least one parameter relevant to cement plug
placement to measure parameters in the well at the predetermined
location; and sending output signals from the sensor to an
operating system located at the surface by means of a cable.
wherein the step of operating the sensor comprises making a caliper
measurement of the well, at least in the region of the
predetermined location, to determine the diameter of the well.
5. A method as claimed in claim 4 wherein the step of operating the
sensor further comprises obtaining a differential pressure
measurement in the fluids in the well in region of predetermined
location.
6. A method as claimed in claim 4, wherein the step of operating
the sensor further comprises making a temperature measurement.
7. (canceled)
8. A method for real-time measurements of the properties of a
wellbore during cement plug placement comprising: providing a pipe
for delivery of the cement plug with a sensor at its end;
introducing the pipe into the well such that its end is at a
predetermined location for placement of the plug; operating the
sensor to measure at least one parameter relevant to cement plug
placement to measure parameters in the well at the predetermined
location; and sending output signals from the sensor to an
operating system located at the surface by means of a cable.
wherein the step of operating the sensor comprises making a caliper
measurement of the well, at least in the region of the
predetermined location, to determine the diameter of the well.
9. The method of claim 8, wherein the step of operating the sensor
further comprises obtaining a differential pressure measurement in
the fluids in the well in region of predetermined location.
10. The method of claim 8, wherein the step of operating the sensor
further comprises making a temperature measurement.
11. The method of claim 8, wherein the calliper measurement is
performed as the pipe is run into the well.
12. The apparatus of claim 2 further comprising a sensor for
temperature measurement.
13. The apparatus of claim 1, wherein the sensor is detachable from
the pipe.
14. The apparatus of claim 12, wherein the caliper, the
differential pressure sensor and the temperature sensor are part of
a sensor package that is detachable from the pipe so as to remain
at the predetermined location in the well and houses a sensor cable
which can be withdrawn to connect the sensor to the operating
system at the surface.
15. The method of claim 5 further comprising making a temperature
measurement.
16. The method of claim 9 further comprising making a temperature
measurement.
17. The method of claim 15, wherein all the measurements are made
by sensors located in a sensor package that is detachable from the
pipe so as to remain at the predetermined location in the well and
houses a sensor cable which can be withdrawn to connect the sensor
to the operating system at the surface.
18. The method of claim 16, wherein, all the measurements are made
by sensors located in a sensor package that is detachable from the
pipe so as to remain at the predetermined location in the well and
houses a sensor cable which can be withdrawn to connect the sensor
to the operating system at the surface.
19. The method of claim 17, wherein the sensor cable is connected
to the pipe such that withdrawal of the pipe from the well causes
the sensor cable to be withdrawn from the sensor package.
20. The method of claim 17, wherein the sensor cable is be
connected to a cable extending along the pipe to the operating
system at the surface.
21. The method of claim 4, wherein the cement plug is made from
Portland cement, magnesium oxychloride cement, epoxy resins, or
geopolymers, and mixtures thereof.
Description
TECHNICAL FIELD
[0001] This invention relates to a method and apparatus for use
during cement plug placement operations of the type encountered in
wells in the oil and gas industry. In particular, the invention
relates to methods using instrumented pipes and downhole
sensors.
BACKGROUND ART
[0002] Cement plugs are placed in wellbores for a variety of
reasons; for curing wellbore instability or losses, plugging a
wellbore or a portion of it, abandoning a wellbore or a section of
it, providing a base for initiating a deviation or kick-off and
more. Cement plugs are constructed by pumping a relatively small
amount of cement slurry down a drill pipe where it later sets
solid.
[0003] FIG. 1 shows a section of a well in which a cement plug is
being set. The well 10 has a viscous pill 12 set in the well 10 at
the bottom of the desired plug location. The end of a drill pipe 14
is then positioned just above the pill 12 and cement 16 is pumped
down the drill pipe 14 into the well to form the plug 18 on the
pill 12. As the plug builds up, the drill pipe is pulled back so
that it does not remain in the plug 18 when it sets. Once all of
the cement has been pumped into the well 10 and the plug 18 has
formed, the drill pipe 14 can be withdrawn and other operations
continued.
[0004] Drilling operations resume once the cement plug has set and
developed enough strength to fulfil its objective, for example to
initiate side tracking or to plug conductive fractures. There is
great uncertainty however about when it is safe to resume drilling
operations, to mitigate the risk of resuming drilling operations
too soon, it is common practice to wait extra time, typically 24
hours.
[0005] Achieving proper placement of the cement plug presents a
challenge as does uncertainty in the downhole temperature;
frequently too much time is allowed for the cement plug to become
set before an attempt to continue well operations is made.
[0006] This invention seeks to overcome many of the challenges
highlighted above by providing real-time measurements of wellbore
properties during cement plug placement.
DISCLOSURE OF THE INVENTION
[0007] A first aspect of the invention provides an apparatus for
placing a cement plug in a well, comprising: [0008] a pipe for
delivering a cement slurry to a predetermined location in the well
to be plugged; [0009] at least one sensor located at a lower end of
the pipe and operable to measure parameters in the well at the
predetermined location; and [0010] an operating system located at
the surface for receiving output signals from the sensor; wherein
the sensor is configured to measure at least one parameter relevant
to cement plug placement and is connected to the operating system
by means of a cable.
[0011] Preferably, the sensor performs a caliper measurement for
indicating hole diameter as the pipe is run into the well
[0012] A particularly preferred embodiment of the invention
comprises a temperature sensor.
[0013] Particularly when the sensor is a temperature sensor, the
apparatus can comprise a sensor package that is detachable from the
pipe so as to remain at the predetermined location in the well and
houses a sensor cable which can be withdrawn to connect the sensor
to the operating system at the surface. The sensor cable can be
connected to the pipe such that withdrawal of the pipe from the
well causes the sensor cable to be withdrawn from the sensor
package. The sensor cable can also be connected to a cable
extending along the pipe to the operating system at the
surface.
[0014] The apparatus preferably further comprises a release
mechanism by which the sensor package is held in the pipe, the
mechanism being operable by means of a body that can be pumped
through the pipe to detach the sensor package on contact with the
mechanism.
[0015] An anchoring system can be provided for securing the sensor
package in position in the well after it is detached from the
pipe.
[0016] A second aspect of the invention provides method of placing
a cement plug in a well, comprising: [0017] providing a pipe for
delivery of the cement plug with a sensor at its end; [0018]
introducing the pipe into the well such that its end is at a
predetermined location for placement of the plug; [0019] operating
the sensor to measure at least one parameter relevant to cement
plug placement and/or to measure parameters in the well at the
predetermined location; and [0020] sending output signals from the
sensor to an operating system located at the surface by means of a
cable.
[0021] The step of operating the sensor can comprise making a
caliper measurement of the well, at least in the region of the
predetermined location, to determine the diameter of the well.
[0022] When the sensor comprises a sensor package housing a sensor
cable which can be withdrawn to connect the sensor to the operating
system at the surface, the method can further comprise detaching
the sensor package from the pipe so that it remains at the
predetermined location in the well, and withdrawing the pipe.
[0023] When the sensor cable is connected to the pipe, the step of
withdrawing the pipe from the well acts to withdraw the sensor
cable from the sensor package.
[0024] The sensor cable can be connected to a cable extending along
the pipe to the operating system at the surface.
[0025] In a preferred embodiment, the sensor package is held in the
pipe by a release mechanism, the method comprising pumping a body
through the pipe to contact the mechanism to detach the sensor
package.
[0026] The sensor package can also comprise an anchoring system,
the method comprising securing the sensor package in position in
the well after it is detached from the pipe by operating the
anchoring system.
[0027] The method according to the second aspect of the invention
is preferably performed using an apparatus according to the first
aspect of the invention.
[0028] The cement can comprise Portland cement, magnesium
oxychloride cement, epoxy resins, geopolymers, etc. Other plugging
material might be used.
[0029] Further aspects of the invention will be apparent from the
following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 shows a prior art cement plug placement
operation;
[0031] FIG. 2 shows an embodiment of the invention;
[0032] FIG. 3 shows a further embodiment of the invention being
lowered downhole;
[0033] FIG. 4 shows the retraction of the wired placement conduit
and unrolling of the communication wire;
[0034] FIG. 5 shows an alternative embodiment whereby the wired
placement conduit is only partially retracted;
[0035] FIG. 6 shows the sensor package released and deployed to the
cement plug; and
[0036] FIG. 7 shows the sensor package being secured to the well
casing by means of a securing device.
MODE(S) FOR CARRYING OUT THE INVENTION
[0037] FIG. 2 shows a first embodiment of the invention, in which
the lower end of the drill pipe 14 is provided with a downhole
measurement package 20 comprising one or more sensors for measuring
parameters in the well. The sensor package is connected back to the
surface by means of a wire or cable 22. The wire or cable 22 can be
run along the inside or outside of the drill pipe 14, and connects
to an operating system 24 at the surface. The cable 22 need not be
continuous, wireless communication systems can be provided for at
least part of the connection to the surface such as at pipe joints
(see U.S. Pat. No. 7,019,665). The sensors in the downhole
measurement package can measure various parameters.
[0038] Including a sonic (or other) caliper measurement on the
wired pipe 14 can give an accurate indication of the well diameter
while running in to place the cement plug. This will allow the
spacer and cement volumes to be recalculated to minimise mixing
(optimise interfaces while pulling out) without loss of rig time
since a separate wireline caliper run may not be required. It has
to be noted that the term cement shall be understood as plug
forming material even if cement is the preferred material.
[0039] A temperature measurement can give an idea of how long to
wait on cement. Sensitivity tests on the cement thickening time
beforehand will lead to optimised waiting time.
[0040] A downhole viscosity measurement can allow the quality of
the viscous plug to be evaluated. If it is insufficient a second
viscous pill can be placed prior to placing cement, thus minimising
the risk of slumping.
[0041] Once the cement plug is placed correctly a temperature (or
other) probe can be dropped into the cement as the drill pipe 14 is
being pulled out. This can be connected via thin conductor or fibre
optic to the wired pipe 14. The temperature monitor can allow
indication of cement setting and pull out at the earliest time.
This is particularly applicable to wells where the pipe is not
pulled out on a routine basis during the setting.
[0042] A further embodiment of the invention provides a method of
optimising cement plug placement by use of a wired placement
conduit. A sensor package is deployed into the cement plug while in
its liquid state prior to setting to take measurements of down hole
properties. The method comprises assembly and deployment of the
wired placement conduit which permits the correct placement of the
sensor package and the unrolling of the communication wire and
deployment of the slurry placement device which activates the
release of the sensor package. Alternatively, the wire can be
coiled on the conduit/drill pipe, from which it would unroll as the
pipe is withdrawn.
[0043] The wired placement conduit is assembled on the surface
prior to deployment. The sensor package and communication wire
rolled as a bobbin are subsequently fastened to the lower end of
the wired placement conduit. The wired placement conduit is lowered
downhole prior to the cement slurry being pumped.
[0044] The slurry placement device is launched from the surface
through the wired placement conduit thus activating the release of
the sensor package. The release of the sensor package generates a
pressure pulse. The wired placement conduit is retracted to the
surface in response to the pressure pulse. The wired placement
conduit may be partially retracted at a distance sufficient to
ensure that the end is clear of the setting material. The
communication wire is unrolled to the surface in response to the
pressure pulse.
[0045] The sensor package is capable of measuring downhole
properties in a similar manner to that described above. These
include but are not limited to; temperature, viscosity, density,
pH, resistivity measurements, differential pressure, elastic
modulus and acoustic impedance. The sensor package may comprise
multiple distributed sensors along the cement plug length. The data
obtained from the sensor package can be used to manage the
operation. For example, a viscous pill may be used in response to
obtaining a low viscosity measurement indicative of slumping.
[0046] The sensor package may be attached to the well at the
desired depth by a securing device. The securing device may
comprise arms which permit contact with the well walls.
[0047] The wired pipe may comprise a drill string. In an
alternative embodiment the wired pipe may comprise coiled tubing.
Devices located on the wired placement conduit permit the
measurement of the hole diameter. Sonic measurements may be taken
to determine hole diameter. Alternatively calipers may be
incorporated to measure hole diameter.
[0048] The communication wire may comprise a fibre optic cable
and/or an electrical cable.
[0049] This invention provides a method and apparatus for deploying
sensors into the liquid cement plug immediately following its
placement and until it is almost set. As the material evolves with
time, an operator can follow in real time its actual properties.
This enables the operator to make informed decisions, based on
these measured properties, of when it is possible to resume
drilling operations. The amount of unproductive time is
minimised.
[0050] FIG. 3 shows the wired placement conduit 30 being deployed
down the wellbore 32. Prior to the wired placement conduit being
lowered downhole it is assembled at the surface with the sensor
package 34 and communication wire 36 rolled as a bobbin fastened to
the lower end of the wired pipe 30. The wired placement conduit may
be either a drill string or coiled tubing. The wired placement
conduit is lowered into the hole 32 and the cement slurry is
pumped. Once the cement plug 38 is in place, the slurry placement
device 40 is launched from the surface through the wired placement
conduit. The slurry placement device may comprise a dart, ball or
other similar device. Upon reaching the end of the wired placement
conduit 30, the slurry placement device 40 hits a seat which
activates the release of the sensor package. 34 A pressure pulse
may be generated and received at the surface providing a positive
indication of the release of the sensor package. 34
[0051] FIG. 4 shows the retraction of the wired placement conduit
30 and unrolling of the communication wire 36; this occurs in
response to the reception of the pressure pulse. When the sensor
package 34 is released the wired pipe 30 is progressively pulled
out of the hole 32. The communication wire 36 unrolls until it
reaches the surface. The communication wire 36 may be an electrical
wire, a fibre optic or a combination of both.
[0052] FIG. 5 shows an alternative embodiment of the invention
whereby the wired placement conduit 30 may only be pulled up a
certain distance to ensure that the end is clear of the setting
material 38 while the sensor package 34 remains in contact with it.
The communication wire 36 connects to the wired placement conduit
30 and the signal is transmitted through the wired placement
conduit 30 to the surface. This embodiment eliminates the need to
retract the wired placement conduit 30 completely to the
surface.
[0053] FIG. 6 shows the sensor package 34 released and deployed to
the cement plug 38. The sensor package 34 is capable of measuring
downhole properties. These include but are not limited to;
temperature, viscosity, density, pH, differential pressure, elastic
modulus and acoustic impedance. The sensor package 34 may comprise
multiple sensors 42 distributed along the cement plug length.
[0054] FIG. 7 shows the sensor package 34 being secured to the
borehole 32 at the required depth by means of a securing device.
The deployment of anchoring arms 44 permits contact to be made with
the well casing 46 to hold the package 34 in place. This avoids the
package sinking out of the plug or rising to its surface, or
becoming displaced by contact with other equipment.
[0055] Other changes can be made within the scope of the
invention.
* * * * *