Journal of Environmental Protection, 2011, 2, 1055-1061
doi:10.4236/jep.2011.28121 Published Online October 2011 (
Copyright © 2011 SciRes. JEP
Pipeline Potential Leak Detection Technologies:
Assessment and Perspective in the Nigeria Niger
Delta Region
Jasper Agbakwuru
Offshore Technology, Faculty of Science and Technology , University of Stavanger, Norway
Received August 9th, 2011; revised September 11th, 2011; accepted October 7th, 2011.
This paper examines the advances in pipeline third party encroachment alert systems and leak control methods in the
oil/gas industry. It also highlights the extent of spill/pollution issues in the Niger Delta region due to intended/unin-
tended damages and suggests a possible method of control. It is believed that the best option to avoid pollution due to
pipeline fa ilure is to ensure that hydrocarbon does not exit fr om the pipeline. With the different methods considered in
this review, acoustic monitoring of change in the operational sound generated from a given pipeline section is sug-
gested to be practicab le to identifying sound abnormalities of th ird party encroachments. One established challeng e of
the acoustic system for buried pipelines protection is attenuation of acoustic transmission. An attempt to check the per-
formance of an acoustic transmission on steel pipelines submerged in water points to a similar research on plastic wa-
ter pipelines that a ttenuation is small compared with pipe buried in soil. Fo rtunately, Niger Delta of Nigeria is made of
wetland, swamps and shallow water and co uld therefore offer an oppo rtunity to deploy acoustic system for the safety of
pipelines against third party attacks in th is region. However, the numerous configura tion and quantity of oil installation
in this region imply that co st of application will be enormou s. It is therefore suggested that a combination of impressed
alternating cycle curren t (IACC) which traces encroachment on the pipeline coating and an acoustic system be used to
manage intended and unintended pipeline potential damages. The IACC should be used for flow lines and other short
distance delivery lines within the o ilfield, while the relatively large diameter and long length delivery, trunk and trans-
mission lines should be considered for acoustic p rotection. It is, however, noted that further efforts are required to re-
duce cost and improve effectiveness of these systems.
Keywords: Pipeline, Leaks, Detection, Niger Delta, Oil Spill, Oil Pollution
1. Introduction
Due to environmental, economic and social cost of hy-
drocarbon leaks, the oil and gas industry places great
importance to the need to minimise ugly events of oil
spill or pollution from occurring. The causes of pipeline
leaks could be categorised into four main classes: Opera-
tional, structural, unintended or intended damages [1].
Operational class includes all leaks from operation of oil
and gas pipelines such as equipment failure (for instance
flange sealing problems due to damaged seals or loose
bolts/nuts), human error etc. Structural problems include
the failure of pipeline in burst, collapse, fatig ue, fracture,
buckling, corrosion (wall thickness loss), and internal
loadings etc. The intended damages come in the form of
terrorist attack, sabotage/theft. The unintended damages
are those that are often caused by construction workers
working in the vicinity of the pipeline.
While it is fair to put that as at today, the industry have
made some significant efforts in building barriers against
the activation of first two classes, there are still chal-
lenges in the latter two, especially, related to cost and
In describing the problem, Yo-Essien of Nigeria oil
spill detection and response agency (NOSDRA) believes
that the enormous oil installations deployed in the Niger
Delta region explains their vulnerability to vandalism.
Presently, the Niger Delta region plays host to 600 oil
fields of which 360 fields are onshore while 240 are off-
shore with over 3000 kilometers of pipelines crisscross-
ing the region and linking some 275 flow stations to
various export terminals. The main area of the delta is
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region
about 46,200 km2 (equivalent to about 1/20th of the area
of the country). According to him, it is pertinent to note
that oil spills resulting from pipeline vandalism has con-
tinued to be a challenge, with most incidents alon g major
pipelines and manifolds [2].
Considering the situation in the Niger Delta of Nigeria,
it is imperative that the different methods and available
technologies be studied in order to suggest a strategy for
research and development in handling the challenges in
the protection of oil and gas pipelines against growing
intended an d unintende d damages.
This paper is motivated by the importance to have full
control of the pipeline against intended and unintended
damages. Recently, the Directorate of Petroleum Re-
sources (DPR, Nigeria) claims that activities of oil theft
cost Nigeria about 300,000 barrels per day. It is also re-
ported that Nigeria lost about $1.5 billion yearly to the
crude oil theft [3]. Of recent, the Chairman of SHELL
Nigeria, claims that the criminal gangs continue to steal
oil from SHELL pipelines at estimated rate of 100,000
barrels per day [3] The Managing Director of SHELL in
his response on the recent publication on oil spill in the
region by the Amnesty International, firms that without
addressing the complex issues in the Niger Delta, and
without all stakeholders playing their part, this problem
will continue to be on th e increase [4]. This is evident in
the statistical oil spill data sh own in Figures 1(a) and (b)
for 2011.
The recent oil spill data from SHELL Nigeria, the
largest oil producing company in Nigeria, indicate that
the majority of the spills have been caused by sabotage
or theft. The recent spill statistical data is shown in Fig-
ures 1(a) and (b).
The several thousands of human lives lost, millions of
barrels of oil spilled to the fragile environment, thou-
sands of people displaced from their homes and millions
of dollars (US) of property destroyed in the region by
pipeline failures have been documented in the literature
Construction/digging activities with improper supervi-
sion and survey in brown fields lead to unintended dam-
ages. Most often, due to fear of consequent liabilities, the
pipeline operator is often not informed of such damages
by the intruding construction contractors or persons, ex-
cept perhaps when such damages result to obvious im-
mediate spill/pollution. Unfortunately, most of these un-
intended damages in the form of external coating dam-
ages, kinks, gouges and dents deteriorate with devastat-
ing consequent failure months or years later causing
safety, environmental and public concern.
This is also a global issue. Chastain (2009 ) quoted the
API recent report of pipeline failure incident in United
States between 1999 and 2006: 77% fatalities, 49 % inci-
Figure 1. (a): Showing the 2011 Oil spill monthly statistics
from pipelines of Shell Nigeria; (b): Showing some yearly
oil spill statistics from pipelines of Shell Nigeria. (Source:
SHELL Oil Spill 2011 data.
dent involving evacuations, 41% of barrels released by
right of way incidents, 27% of incidents involving a re-
lease of 50 barrels or more [8].
Clearly, the prevention of damage to the pipeline must
be an industry priority. Unfortunately, pipeline operators
appear to have inadequate cost effective industrial tech-
nology to manage most of the pipeline exposures that
generates pollution, sp ill or loss of hydrocarbon oil from
containments such as pipelines in the class of intended
and unintended actio ns. It is noted that till date, there h as
never been an effective solution for securing pipelines
against damage caused by terror, sabotage, theft [9,10].
A lot of patents and methodologies have been devel-
oped for the pu rpose of leak identificatio n using acoustic
signatures [11]. These efforts in our opinion is reactive in
nature and a proactive action is required in preventing
exit of oil content of oil pipelines uncontrollably to the
environment with its attendant environmental, economic
and social consequences.
opyright © 2011 SciRes. JEP
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region1057
In this paper, various methods of hydrocarbon spill/
leak control and barriers used by the industry today have
been considered. Most of the review of the technologies
in this work is on an industrial context. Therefore it will
be discussed with reference to the work of pipeline in-
tegrity maintenance and inspection companies most of
whom are members of the Offshore Technology com-
munity [12]. This group has been selected as they are
among the known major operators of innovative and
modern systems for pipeline integrity systems, leaks and
2. Review of Leak Detection Methods
The methods and techniques for the detection of hydro-
carbon leaks from pipelines as used by the oil and gas
industry to-date is reviewed and can be categorised into
nine main classes based on the principle of operation (see
Table 1). Details of these methods have been detailed in
a review of the Pipeline Leaks and Inspection Technolo-
gies in the Oil and Gas Industry [13]. It is noted that
most of the system above could be integrated to the Su-
pervisory Control and Data Acquisition (SCADA) for
alert systems in line with API RP1167.
There has been a recent development in the observa-
tions of leaking pipelines in muddy water. This devel-
opment became necessary due to the underwater poor
visibility inheren t in the Niger Delta region, especially in
the wet season [14]. Further work is in progress to en able
the system to operate remotely to locate leaks.
The methods tabled in Table 1 have been identified to
be useful in two areas:
1) Identifications of available leaks irrespective of the
class of the causal damage
2) Potential leaks identification due to metal loss
(corrosion, gouges etc.).
3. Review of Potential Leak Detection
These are controls that are in place to stop or prevent
events that would otherwise lead to escape of oil from
the pipeline.
3.1. Acoustic Systems
The acoustic impact detection system often comprise of
multiple acoustic sensors, power supply and remote
transmitting devices which are placed along the pipeline
at fixed intervals.
Pipeguard technology developed by Magal Security
Ltd (Israel) is perhaps one of the recent technologies in
this field. The company has been granted a research and
development grant in March-2011 to further enhance its
PipeGuard technology for protection of gas pipelines.
Multiple Pipeguard sensors are typically interconnected
Table 1. Categorisation of leak detection methods.
Leak detection methods
SN Method Examples of tool/systems that use the
1Laser Scanning Laser scanning, Buckle detectors, etc.
2Ultrasonic Intelligent pigging, Automatic
ultrasonic tester, TOFD, Ultrasonic
probe testers etc.
3Acoustic Acoustic Leak detector, hydrophones ,
Electromagnetic Acoustic T ransducers
(EMAT), piezoelectric meter etc.
4Fibre Optics Optical sensors (for leak, strain, fatigue
and ground movement detection), etc
5Visual Inspection Use of human eye, Inspection light,
Robotic crawlers etc.
6Magnetic flux
leakage method Int elligent pigging, Eddy current,
Magnetic particle inspection etc.
7Inventory accounting
(pressure differentials,
mass flow-rates etc)Negative pressure wave detectors
Hydrocarbon Leak
detection sensors
Fluorescence detectors, Hydrochemical
9Temperature based
sensors Thermal spray technology etc.
by wireless or cellular mesh network and alarms are dis-
played on geospatial map before the damage is done.
Reception of raw seismic signalling is achieved using
several geophones in a row, highly sensitive to the fre-
quency domain, typical to the act of digging. The loca-
tion of the identified threat is derived from accurate
measurement of the signal at each sensor both in term of
direction and distance from the unit [9]. The company
has extended this to th e use of infrasonic seismic sensors
with the ability of identifying threats based on their
acoustic signatures. The sensors are installed few feet
above the pipeline structure [8].
General Electric (GE) developed a related system
popularly called ThreatScan. The ThreatScan is used for
both buried and above ground pipelines. The power sup-
ply is solar with a battery back-up for “no sun” condi-
tions. Each sensor communicates directly with the satel-
lite system and relays data to the GE’s monitoring facil-
ity where it is analysed [8,15]. It can be used for Sabo-
tage warning and detection of illegal hot tapping (prod-
uct theft) but in our opinion, the characteristic alert noti-
fication up to 0 - 30 mins is adequate to pipeline intru-
sion to happen uncontrolled, jeopardising the essence of
the system. This tool is currently in use by some pipeline
operators in the USA.
3.2. Patrols and Satellite
Pipeline patrol and Security guards is the act of patrol-
ling the pipeline right-of- way (ROW), keeping watch
Copyright © 2011 SciRes. JEP
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region
over the pipeline by air, land or sea. Use of remotely
piloted aerial patrol drones can provide video or photo-
graphic features for pipeline right of way monitoring.
The use of satellite is also being considered in some
quarters. For pipelines in creeks, swamps and difficult
terrain and where the pipelines run into thousands of
kilometre, in a spaghetti network in mangrove trees and
creeks as in the Nigeria Niger Delta region, this method
becomes almost impossible.
3.3. Fibre Optics Systems
A project was initiated by the US department of Energy,
Office of Fossil Energy in this area in 2001 and the over-
all objective was to develop and demonstrate an optical
fiber intrusion detection device that would prevent out-
side force damage by detecting and alarming when con-
struction equipment is near the pipeline vicinity [16].
The principle used in this project was that when heavy
equipment comes into the right of way, it compresses the
soil and creates vibration which changes the dynamics of
the light and reflects the changes to the source. Field
testing of the basic concept has been proved. However,
according to the report of the project close-out, the sensi-
tivity of the technique needs substantial improvement to
be practiced in the industry [8]. This project was cham-
pion by Gas Technology Institute (GTI).
A similar product developed by Future Fibre Tech-
nology (FFT) differs by sending continuous signal in-
stead of pulse light. Their system has also three sensing
fibre strands instead of one strand used in the GTI pro-
ject. Two fibre strands measure the changes in the mo-
tion, sound or vibration while the third delivers informa-
tion to determine location of the event. This tool is cur-
rently being used in Europe and USA [8]. Both systems
however require the fibre to be installed along and close
vicinity to the pipeline
3.4. The Impressed Alternating Cycle Current
This is a kind of pipeline monitoring method consisting
of impressing electrical signals on the pipe by generating
a time-varying voltage between the pipe and the soil at
periodic locations where pipeline access is available. The
signal voltage between the pipe and ground is monitored
continuously at receiving stations located some distance
away. Third party contact to the pipe that breaks thro ugh
the coating changes the signal received at the receiving
stations. Based on information recently found in pub-
lished studies, it is believed that the operation of IACC
on a pipeline will cause no interference with CP systems
[17]. Initial results on operating pipelines showed that
IACC signals could be successfully propagated over a
distance of 3.5 miles (5.63 km), and that simulated con-
tact can be detected up to a distance of 1.4 miles (2.4
km), depending on the pipeline and soil conditions [17].
This method will allow existing pipelines to be retrofit-
ted for monitoring without excavation because the tech-
nique uses existing cathodic protection (CP) test points.
In addition, the method could be readily applied to new
Huebler, (2002) gave the benefits and drawbacks of
the technologies especially for pipeline right of way in-
trusion detection [10], many of which are presented in
Table 2.
4. Discussion
The application of the acoustic methods in the manner of
the most recent technology may require modifications for
use in submerged steel pipelines and manifolds where
attack or encroachment on a pipeline is not through the
act of “digging or ground breaking”. Verification of per-
formance of the acoustic method in submerged pipeline
is yet to be documented. An experience to trace acoustic
transmission on water pipeline at depth of 12 m suggest
that it would not pose a bigger challenge and may even
prove to be easier than land based pipelines. This ex-
perience conforms to the work of Muggleton and Bren-
nan (2004) on the sound attenuation in plastic pipelines
submerged in water. They found that energy does not, in
fact, radiate into the water and the attenuation is small
compared with that for a pipe buried in soil [18].
In managing the noise level in acoustic methods, it
could be possible to study sound generated from a given
pipeline and identify the anomalies that could occur in
the form of act of digging, cutting, ho t tapping and drill-
ing. And then concentrate on monitoring deviation from
“normal” noise levels as a measure of control. This sug-
gestion is relevant because most of the trunk and trans-
mission pipelines on land are located alongside motor-
able roads from where most noise could be generated.
(Using fibre optics in this scenario would lead to a lot of
noise generation). The oil field stations in the region are
not too distant from each other. The implication is that
the acoustic and alternating current attenuation may be
managed by localising the monitoring system to closest
station as possible and identifying the “normal” condi-
Pipeline networks in most oilfields in the Niger Delta
of Nigeria are more or less “spaghetti” in swamps and
shallow water. Unfortunately, the networks of pipelines
are often the small flow lines in the range of 4 inch to
8inch running from various points and sometimes cross-
ing each other. Use of acoustics and fibre optics methods
for these small diameter pipelines for detection of in-
tended and unintended damages would be technically
and financially cumbersome. New method or combina-
tions of me t hods wo ul d therefore be req ui red.
opyright © 2011 SciRes. JEP
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region
Copyright © 2011 SciRes. JEP
Table 2. Benefits and draw bac ks of the tec hnologies.
Comparison of different technologies
SN Technology Benefits Drawback
1 Satellite monitoring at visible wavelengths. No equipment to install on ground. Uses
commercial satellites. Possible replacement
for weekly flyovers of pipelines.
Requires sunlight. Affected by cl oud co ve r. A
method is needed to pick out acti vi ty over narrow
pipeline in broad image
2 Satellite monitoring at several wavelengths. Could detect encroachment at night an d
through cloud cover.
Requires more than one satellite. A method is
needed to pick out activity over narrow pipeline in
broad image.
3 Ground-based visual surveillance. Can use commercially available cameras.
System is needed to minimize the amount of
human monitoring. May not see directional boring
encroachment. Separate camera needed for each
4 GPS system and computerized pipeline
maps. No equipment installed on pipeline.
Requires equipment on each piece of construction
equipment. Requires equipment operators to
maintain equipment. Restricted use in right of way
5 The impressed alternating cycle current
(IACC). Continuous monitoring. Could be u sed in
conjunction with acoustic det e ct i o n .
Detects rather than prevents damage. Requires
breaking of coating for detection. Requires
minimum breaks in pipeline coating.
6 Acoustic detection of impacts.
Continuous monitoring. Localized
installation of sensors. Could be used in
conjunction with cathodic prot ec ti o n
Detects rather than prevents damage. Sensors
attached to outside pipe wall. Only one chance to
detect transient signal. Issues of background noise
must be solved. May be too costly if close sensor
spacing is required.
7 Distributed optical fibe r with
interferometr-ic detection. Continuous m on i t o ring. Sam e for m factor as
pipeline. Sensitive technique
Continuous fiber must be installed along pipeline.
Methods are needed to distinguish hazardous and
benign encroachment . Detects changes to the entire
fiber cannot distinguish simultaneous events or
events plus benign encroachment.
8 Distributed optical fiber with optical time
domain reflectometry.
Potential to monitor miles of pipeline from
each location.Continuous monitoring. Same
form factor as pipeline. Can detect and
distinguish simultaneous events at different
points along optical fiber.
Continuous fiber must be installed along pipeline.
Methods are needed to distinguish hazardous and
benign encroachment.
*Part-sourced from [11].
Figure 2 is a map of major oil and gas p ipelines in the
Niger Delta. The sum of oil and gas pipelines in the
Western and Eastern regions is indeed a congested field.
So far, it appears that the best proposal could be a
combination of Impressed Alternating Cycle Current
(IACC) and the Acoustic methods. The IACC would be
employed in the short and congested relatively smaller
diameter lines. The acoustic would be used for longer
transmission, trunk and distribution lines. Further im-
provement in terms of cost and effectiveness however, is
required for the acoustic system.
Directional drilling HDD pipe laying equipment was
recently used to lay a gas pipeline 45 metres beneath the
1.7 km Escravos River [19]. This approach has been felt
in different quarters to be the future oil and gas pipeline
installation to end the pipeline vandalism and illegal oil
bunkering in the oil industry in the Niger Delta region
The technology seems attractive for new pipelines,
especially long distance pipelines, but the attendant pipe-
line maintenance issues and over-burden problems re-
main a concern, especially in the future.
5. Conclusions
This section has, in summary term, attempted to discuss
the complex and diverse subject of leaks and potential
leak detection. The oil theft and pollution in the Niger
Delta region have shown an increasing trend over the
years and the consequence of technology and research
not growing to cover the challenges posed by these could
further complicate the social, economic and environ-
mental concerns in this region.
There is indeed a growing need for potential leak de-
tection technologies in the area of intended and unin-
tended pipeline damages in the Nigeria Niger Delta as in
many other part of the world. In proposing a combination
of IACC and an acoustic system in this region, it is
hoped that efforts would be made to test the integration
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region
Figure 2. A Map of Nigerian Niger Delta showing some oil
fields and pipelines (Source: Urhobo Historical Society,, As-
sessed 26.07.2011).
and workability in terms of cost and effectiveness.
6. Acknowledgements
One does express his gratitude to AS Norske SHELL fo r
provision of fund for the research studies in the area of
oil/gas leak detection technologies. I also acknowledge
the efforts of the Prof. Gudmestad O. T., for taken time
to review and suggest improvement to this review work.
[1] E. W. McAllister, “Pipeline Rules of Thumb Handbook:
Quick and Accurate Solutions to Your Everyday Pipeline
Problems,” 6th Edition, 2005, pp. 547-556.
[2] L. P. E. Yo-Essien, “Oil Spill Management in Nigeria:
Challenges of Pipeline Vandalism in the Niger Delta Re-
gion of Nigeria,” National Oil Spill Detection and Re-
sponse Agency (NOSDRA) Abuja, 2008.
[3] E. Ugwuani, “Shell Records 2580 Barrel Oil Spill,” The
Nations, 7 June 2011.
[4] M. Sunmonu, “SPDC Response on Amnesty International
Publication on Spills in the Niger Delta,” 2010.
[5] K. N. Aroh, I. U. Ubong, C. L. Eze, I. M. Harry, J. C.
Umo-Otong and A. E. Gobo, “Oil Spill Incidents and
Pipeline Vandalization in Nigeria: Impact on Public
Health and Negation to Attainment of Millennium De-
velopment Goal: The Ishiagu Example,” Disaster Pre-
vention and Management, Vol. 19, No. 1, 2010, pp. 70-87.
Emerald Group Publishing Limited.
[6] P. O. Olajide, S. O. Ajisebutu, S. B. Williams and L. B.
Ogbeifun, “Fish Kills and Physiochemical Qualities of
Crude Oil Polluted River in Nigeria,” Research Journal
of Fisheries and Hydrobiology, Vol. 4, No. 3, 2009, pp.
[7] Amnesty International, “Nigeria: Petroleum, Pollution
and Poverty in the Niger Delta,” Index: AFR 44/017/2009,
[8] S. Chastian, “Pipeline Right of Way Encroachment: Ex-
ploring Emerging Technologies That Address the Prob-
lem,” Documents and Resource for Small Business and
Professionals, 2009.
[9] Press Release, “Magal Receives R&D Contract to En-
hance Its Pipeguard Technology for Protection of Gas
Pipelines,” Research Sponsored by a Large US Gas Util-
ity, 2011.
[10] J. E. Heubler, “State-of-the-Art in Detection of Unautho-
rized Construction Equipment in Pipeline Right-of-Way,”
Transport Research Board of Academics, GTI Project
61139, 2002, p. 28.
[11] Free Patents Online, “All Inventions of Mankind”,
Available at:
[12] The Website for the Offshore Oil and Gas Industry,
“Pipeline Inspection and Maintenance,” 2011.
[13] J. Agbakwuru, “A Review of Pipeline Leaks and Inspec-
tion Technologies in the Oil and Gas Industry,” Pipeline
Course of the University of Stavanger, Unpublished,
[14] J. A. Agbakwuru, O. T. Gudmestad, J. Groenli and H.
Skjaveland, “Development of Method/Apparatus for
Close-Visual Inspection of under-Water Structures (Es-
pecially Pipelines) in Muddy and Unclear Water Condi-
opyright © 2011 SciRes. JEP
Pipeline Potential Leak Detection Technologies: A s sessment and Perspective in the Nigeria Niger Delta Region
Copyright © 2011 SciRes. JEP
tion,” Proceedings of the 30th International Conference
on Ocean, Offshore and Arctic Engineering, OMAE,
Rotterdam, 19-24 June 2011.
[15] GE Oil and Gas, “PII Pipeline Solution ThreatScan: Real
Time Monitoring for Threats and Impacts on Pipelines”,
[16] US Department of Energy, Office of Fossil Energy, “De-
tection of Unauthorized Construction Equipment in
Pipeline Right-of-Way, 2011. doc=256
[17] G. L. Burkhardt and A. E. Crouch, “Realtime Monitoring
of Pipelines from Third-Party Contact,” Semi-Annual
Technical Progress Report No.4, Cooperative Agreement
DE-FC26-03NT41878, Southwest Research Institute®
Project 14.10211, 2005.
[18] J. M. Muggleton and M. J. Brennan, “Leak Noise Propa-
gation and Attenuation in Submerged Plastic Water
Pipes,” Journal of Sound and Vibration, Vol. 278, No. 3,
2004, pp. 527-537. doi:10.1016/j.jsv.2003.10.052
[19] D. K. Olofin, Gulf Oil Co., Western Geophysical Co. and
R. A. Will, “Acquisition and Processing of Shallow Wa-
ter 3-D Seismic Surveys over Producing Fields in the
Northwest Niger Delta Offsho re,” Technology Conference,
Houston, 6-7 November 1989.
[20] S. Adebayo, “HDD Technology Takes Pipeline Across
1.7 km Escravos River,” Fortune Business, 2010.