U.S. patent application number 16/075411 was filed with the patent office on 2019-03-07 for leak detection system for intermittent use pipelines.
The applicant listed for this patent is Halliburton Energy Services, Inc.. Invention is credited to Mikko Jaaskelainen, Brian V. Park.
Application Number | 20190071965 16/075411 |
Document ID | / |
Family ID | 60267034 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190071965 |
Kind Code |
A1 |
Jaaskelainen; Mikko ; et
al. |
March 7, 2019 |
LEAK DETECTION SYSTEM FOR INTERMITTENT USE PIPELINES
Abstract
A system is described for reliably detecting leaks in a
distributed manner in intermittent use pipelines by making use of
thermal or acoustic events triggered by the leak. The system can
work in pressurized or unpressurized pipelines and in high flow or
no flow conditions.
Inventors: |
Jaaskelainen; Mikko; (Katy,
TX) ; Park; Brian V.; (Austin, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Halliburton Energy Services, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
60267034 |
Appl. No.: |
16/075411 |
Filed: |
May 11, 2016 |
PCT Filed: |
May 11, 2016 |
PCT NO: |
PCT/US2016/031808 |
371 Date: |
August 3, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F17D 5/02 20130101; F17D
5/04 20130101; G01M 3/38 20130101; G01M 3/047 20130101; E21B 47/135
20200501; E21B 47/06 20130101; E21B 47/117 20200501; E21B 47/113
20200501; G01M 3/002 20130101 |
International
Class: |
E21B 47/10 20060101
E21B047/10; E21B 47/06 20060101 E21B047/06; E21B 47/12 20060101
E21B047/12 |
Claims
1. A system for detecting pipeline leaks for intermittent use
pipelines comprising: a pipeline to carry a pipeline product that
is be of at least intermittent use; a trough in which the pipeline
is to rest; at least one optical fiber distributed sensing cable to
run through the trough and to be located below the pipeline;
separated baffles located along the trough to support the pipeline
and to control a spacing between the pipeline and the at least one
optical fiber distributed sensing cable; and a reactive material to
be positioned in a bottom of the trough and to be in contact with
the at least one optical fiber distributed sensing cable; wherein
the reactive material is to react with the pipeline product if the
reactive material comes in contact with the pipeline product,
creating at least one of a thermal and an acoustic event.
2. The system of claim 1 wherein the at least one optical fiber
distributed sensing cable is part of a distributed temperature
sensing (DTS) system that is to detect thermal events along the
pipeline.
3. The system of claim 1 wherein the at least one optical fiber
distributed sensing cable is part of a distributed acoustic sensing
(DAS) system that is to detect acoustic events along the
pipeline.
4. The system of claim 1 wherein the pipeline product is a
hydrochloric acid, wherein the reactive material at the bottom of
the trough is calcium carbonate that is to react with the
hydrochloric acid, releasing thermal energy that to be measured by
a DTS system.
5. (canceled)
6. The system of claim 1 wherein the trough in which the pipeline
rests comprises a V-shaped bottom.
7. The system of claim 1 wherein the reactive material is in
granular form.
8. The system of claim 1 wherein a material of the pipeline is a
hydrocarbon, wherein the reactive material is a material that is to
dissolve in hydrocarbons, releasing acoustic energy that is to be
measured by a DAS system.
9. (canceled)
10. The system of claim 1 wherein the reactive material is supplied
as at least one of a gel and a brick form that is to stay in place
in sloped pipeline deployments.
11. The system of claim 1 wherein the reactive material in the
bottom of the trough is supplied encapsulated within a sensing
cable to run through the trough and located below the pipeline.
12. A system for detecting pipeline leaks for intermittent use
pipelines comprising: a pipeline carrying a pipeline product that
is to be of at least intermittent use; a trough located in a trench
in soil and with retaining walls surrounding the trench, wherein
the pipeline is to be positioned in the trough; at least one
optical fiber distributed sensing cable to run through the trough
and to be located below the pipeline; a reactive material in a
bottom of the trough and covering the at least one optical fiber
distributed sensing cable; wherein the reactive material is to
react with the pipeline product in response to being in contact
with the pipeline product, creating at least one of a thermal and
an acoustic event; and a trench lid to be placed on the retaining
walls after deployment of the trough, the pipeline, the at least
one optical fiber distributed sensing cable, and the reactive
material.
13. The system of claim 12 wherein the at least one optical fiber
distributed sensing cable is part of a distributed temperature
sensing (DTS) system and is to detect thermal events along the
pipeline.
14. The system of claim 12 wherein the at least one optical fiber
distributed sensing cable is part of a distributed acoustic sensing
(DAS) system and is to detect acoustic events along the
pipeline.
15. The system of claim 12 wherein the pipeline product is a
hydrochloric acid, wherein the reactive material at the bottom of
the trough is calcium carbonate that is to react with the
hydrochloric acid, releasing thermal energy that is to be measured
by a distributed temperature sensing (DTS) system.
16. (canceled)
17. The system of claim 12 wherein the trough in which the pipeline
rests comprises a V-shaped bottom.
18. The system of claim 12 wherein the reactive material is in
granular form.
19. The system of claim 12 wherein a material of the pipeline is a
hydrocarbon, wherein the reactive material is a material that is to
dissolve in hydrocarbons, releasing acoustic energy that is to be
measured by a distributed acoustic sensing (DAS) system.
20. (canceled)
21. The system of claim 12 wherein the reactive material is
supplied as at least one of a gel and a brick form that is to stay
in place in sloped pipeline deployments.
22. The system of claim 12 wherein the reactive material in the
bottom of the trough is supplied encapsulated within a sensing
cable to run through the trough and located below the pipeline.
23. A system for detecting pipeline leaks for intermittent use
pipelines comprising: a pipeline to carry a pipeline product that
is to be of at least intermittent use; at least one optical fiber
distributed sensing cable to be positioned beneath the pipeline;
and a reactive material supplied encapsulated within a sensing
cable located below the pipeline; wherein the reactive material is
to react with the pipeline product in response to being in contact
with the, creating at least one of a thermal and an acoustic
event.
24. The system of claim 23 wherein the optical fiber distributed
sensing cable is part of at least one of a distributed temperature
sensing (DTS) system that is to detect thermal events along the
pipeline and a distributed acoustic sensing (DAS) system that is to
detect acoustic events along the pipeline.
25. (canceled)
Description
BACKGROUND
[0001] The purpose of the invention is to enable leak detection in
pipelines where the pipeline is intermittently used, i.e. extended
periods of inactivity with low or no pressure in an environment
where the pipeline fluid may approach the environmental ambient
temperature. The pipeline may contain hydrocarbons, or for example
be a buried hydrochloric acid pipeline intermittently used for
down-hole well stimulation. Hydrochloric acid is often used to
stimulate carbonate reservoirs by dissolving the carbonate
formation, and the ground where the pipeline is buried may also be
carbonate, which may be a concern if the hydrochloric pipeline
leaks. The great challenge with any non-pressurized and
intermittently used pipeline is the ability to detect a leak at any
time.
[0002] Conventional leak detection systems utilize single point
field instrumentation (e.g. for flow, pressure, fluid temperature)
to monitor internal pipeline parameters, and these pipeline
parameters are subsequently used for inferring a leak.
[0003] The issue with each of these types of sensors is: (a) when
there is no flow, then the flow sensors used to measure normal
flows will not be able to detect the low flows of a leak; (b) when
there is no pressure then pressure sensors cannot detect a pressure
change due to a leak; and (c) with a buried pipeline and no flow
the pipeline contents will approach environmental temperatures so
temperature sensors will not detect a leak.
[0004] Similarly, distributed fiber optic sensors like Distributed
Temperature Sensing (DTS) or Distributed Acoustic Sensing (DAS)
systems rely on deviations from a base line. But DTS systems--rely
on the leaked fluid having a different temperature than the
location where the optical fiber distributed sensing cable is
located. This may not be the case with a buried pipeline where the
fluid may approach the environmental temperature over time when the
pipeline isn't in use. In the case of DAS systems--they rely on
acoustic noise generated when the pipeline is pressurized and the
sound generated when the fluid escapes the high pressure inside the
pipeline. But this may not be case when the pipeline is inactive
and not pressurized.
[0005] There are consequences to not detecting a leak. In the case
of hydrochloric acid pipeline leaks during the inactive time may
leak without means to detect the event. And the acid may then
dissolve the carbonate foundation on which the pipeline rests, and
other structures may also be impacted by a large acid leak.
[0006] There is a need for a better system that can detect small
leaks during normal operation and also leaks during periods between
well stimulation and pipeline usage if fluid is left in the
pipeline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 FIG. 1 illustrates prior art deployment of optical
fiber for pipeline leak detection.
[0008] FIG. 2 illustrates an enhanced deployment method where
environmental effects may be reduced.
[0009] FIG. 3 illustrates a side view of the deployment of FIG.
2.
[0010] FIG. 4 illustrates a system that could achieve the desired
objective.
[0011] FIG. 5 illustrates an alternate embodiment in which a
pipeline may be placed in a trough inside a buried trench.
DETAILED DESCRIPTION
[0012] In the following detailed description, reference is made to
accompanying drawings that illustrate embodiments of the present
disclosure. These embodiments are described in sufficient detail to
enable a person of ordinary skill in the art to practice the
disclosure without undue experimentation. It should be understood,
however, that the embodiments and examples described herein are
given by way of illustration only, and not by way of limitation.
Various substitutions, modifications, additions, and rearrangements
may be made without departing from the spirit of the present
disclosure. Therefore, the description that follows is not to be
taken in a limited sense, and the scope of the present disclosure
will be defined only by the final claims.
[0013] The invention use materials deployed in the fluid leak path
and the materials are selected such that exothermic reactions occur
when the fluid contacts the material. The optical fiber distributed
sensing cable is placed inside a trough to control leaked fluids
towards the material and sensing cable such that the exothermic
event is detected when the fluid contacts the material.
[0014] FIG. 1, shown generally as 100, illustrates prior art
deployment of optical fiber for pipeline leak detection. The
optical fiber cable 140 is buried below the pipeline 120 such that
there is a thermal gradient between the pipeline 120 and the
location where the sensing fiber optic is located. A leak 130 will
cause fluid 150 of a one temperature to seep into the ground and
eventually reach the optical fiber distributed sensing cable in an
environment with a different temperature. This is detected by the
fiber optic sensing system. The underlying assumption here is that
there is a difference in temperature between the optical fiber
distributed sensing cable 140 and the pipeline product, and that
sufficient amount of pipeline product reaches the sensing cable to
generate a decent size thermal event. This may not always be true
due to soil variations, seasonal temperature changes, rain and
other environmental effects.
[0015] FIG. 2, shown generally as 200, shows an enhanced deployment
method where environmental effects may be reduced. A pipeline 210
is trenched and a glass fiber reinforced plastic (GRP) trough 250
is located in the trench (trench not shown). Baffles 240 located
along the trough support the pipeline and control the spacing
between the pipeline 210 and optical fiber distributed sensing
cable 230, and also provide a barrier for fluid migration in case
of a leak. A lid 220 may be attached on top of the trough to
provide an environment where rain and other environmental effects
are reduced and thereby generate a more stable environment for the
sensing system. The space inside the trough may be filled with
gravel or other suitable materials to support the weight of the
pipeline 210 when filled while proving a good migration path for
fluid from a pipeline leak down to the optical fiber distributed
sensing cable 230. The V-shaped bottom of the trough 250 will focus
leaked fluids towards the optical fiber distributed sensing
cable.
[0016] FIG. 3, shown generally as 300, illustrates a side view of
the arrangement of FIG. 2. Pipeline 210, containing pipeline
product 320 rests on the structure of the baffles 240. The optical
fiber cable 230 is located at the lowest part of the arrangement
and any leaked pipeline product 340 from leak 330 naturally
collects there surrounding the detecting fiber cable 230.
[0017] The arrangement in FIGS. 2 & 3 will enhance the ability
to detect a pipeline leak, but there may still be conditions where
the thermal differences between the pipeline product and the
optical fiber distributed sensing cable is very small. So what is
needed is a system that can detect very small leaks.
[0018] One example of such a system could be a pipeline used for
acid transportation. Hydrocarbon wells drilled in carbonate
reservoirs are commonly stimulated by acid injection of e.g.
hydrochloric acid where the acid dissolves the carbonate and
increase the flow area to contact a larger reservoir volume. The
surface infrastructure may be located on carbonate rock and a leak
would have a serious negative impact on the foundation of the
infrastructure. It is therefore desirable to have a leak detection
system that can monitor leaks irrespective of environmental
conditions.
[0019] FIG. 4 shown generally as 400, illustrates a system that
will achieve the desired objective. FIG. 4 shows the system in
FIGS. 2 & 3 with the addition of a material 410 located at the
bottom of the trough. In the case of an acid pipeline the material
can be calcium carbonate as it is well known that it will cause a
strong exothermic reaction when in contact with the hydrochloric
acid. The rise in temperature will depend on the actual
concentration of the acid and the material, in this case calcium
carbonate even though other similar chemicals obviously fall within
the scope of the invention. This will generate an event that will
deviate from the thermal base line regardless of environmental
conditions, whether there is flow or not, pressure or not, and can
easily be detected with a DTS monitoring system. The reaction
between the acid and calcium carbonate will bubble and also
generate noise when the bubbling of the chemical reaction occurs,
and this can be detected with a DAS system. The optical fiber
distributed sensing cable may be coated in a material that is acid
resistant, e.g. Teflon. Other materials well known to generate
exothermic reactions with hydrochloric acid include e.g. lithium,
potassium, calcium, sodium, magnesium, aluminum, zinc, iron and
lead. Suitable materials may be selected based on applications and
desired thermal response as e.g. zinc may generate a thermal event
of around 8-10 C whereas magnesium may generate a vigorous thermal
event of up to 60 C. It may however not be desirable to have
materials like lithium and magnesium in some applications due to
the material properties.
[0020] Water may also be used in the trough because hydrochloric
acid gives off heat when it is added to water. The limitation is
that water may evaporate or leak off in time, so a solid material
like calcium carbonate has the advantage of being permanent.
[0021] Similarly, thermal and acoustic signatures can be generated
with other material combinations. The materials may be designed for
other pipeline products to for example release acoustic energy when
wetted. Thus a custom product with stored acoustic or mechanical
energy may be housed in a material that will dissolve when in
contact with, for example, hydrocarbons, and the released energy
may be detected with a Distributed Acoustic Sensing (DAS)
system.
[0022] As an alternative to fluid or granular reactive materials
the granular material could be supplied as a gel or bricks to
facilitate keeping the reactive material in place for pipelines
with steep slopes.
[0023] The reactive material can also be made available in other
ways. In an alternative embodiment it can be supplied encapsulated
within a sensing cable. Sensing cables may have various
encapsulations and/or fillers, and it is common for these
encapsulations to be extruded onto the sensing cables or fillers
may be added to the cable construction. The encapsulation material
may be melted during the process and it may possible to mix
materials with exothermic reaction into the extrusion process, or
various filler materials can be manufactured to include exothermic
materials.
[0024] It is also common to add tape on top of sensing cables or in
cable layers and this is another possible embodiments where layers
of tape are used and where one layer may include materials with
exothermic properties. The encapsulation may then act as an
exothermic barrier around the sensing cable, or the outer layer of
a sensing cable may dissolve when exposed to the pipeline fluid to
expose layer/fillers/tape with exothermic materials.
[0025] Making use of the encapsulation approach described above an
alternate embodiment could be employed in which no trough is needed
and no baffles, similar to that shown in FIG. 1. The sensing cable
with encapsulated reactive material could be deployed directly
below the pipeline and gravity would drive any liquid leaks to seep
down and active the reactive material within the sensing cable. As
with the other approaches described the distributed sensing could
be either DTS or DAS systems.
[0026] In an alternate embodiment as shown generally as 500 in FIG.
5 the concept can be applied by use of retaining walls 510 around a
trench dug into any soil 515 with a simple trough 520 inside the
retaining walls and carrying a pipeline 530 for delivering a
pipeline product 550. Optical fiber sensing cables 535 can be
placed under the pipeline and a material 540 that is reactive to
product 550 is poured into the trough so that it covers the optical
fiber sensing cables. The material might be liquid or a granular
solid. Once in place a trench lid 560 could be placed in place to
protect the pipeline in place and to offer convenient access to the
pipeline for maintenance purposes.
[0027] Value Added
[0028] Earlier attempts rely on the thermal difference between the
pipeline product and the environment where the optical fiber
distributed sensing cable is located, and this condition may not be
satisfied thus resulting in a leak detection system that cannot
detect leaks under certain environmental conditions. The invention
generates a thermal event triggered by a leak regardless of
environmental conditions.
[0029] Although certain embodiments and their advantages have been
described herein in detail, it should be understood that various
changes, substitutions and alterations could be made without
departing from the coverage as defined by the appended claims.
Moreover, the potential applications of the disclosed techniques is
not intended to be limited to the particular embodiments of the
processes, machines, manufactures, means, methods and steps
described herein. As a person of ordinary skill in the art will
readily appreciate from this disclosure, other processes, machines,
manufactures, means, methods, or steps, presently existing or later
to be developed that perform substantially the same function or
achieve substantially the same result as the corresponding
embodiments described herein may be utilized. Accordingly, the
appended claims are intended to include within their scope such
processes, machines, manufactures, means, methods or steps.
* * * * *