In pipeline surveillance, satellite methods discussed in Peng, Yun and Hong Kong are widely used in the USA and Canada because the majority of their pipeline incidents are due to excavation damages. In Europe however, the Unmanned Aerial Vehicles (UAV) method is attracting some interests since they might be utilized in mission critical tasks that present high safety risks for people. Also fiber optics method is usually used due to high sensitivity of fiber optic sensors as applied to leakage detection. WSN comprises motes otherwise referred to as wireless sensor nodes that are interconnec
In pipeline surveillance, satellite methods discussed in Peng, Yun and Hong Kong are widely used in the USA and Canada because the majority of their pipeline incidents are due to excavation damages. In Europe however, the Unmanned Aerial Vehicles (UAV) method is attracting some interests since they might be utilized in mission critical tasks that present high safety risks for people. Also fiber optics method is usually used due to high sensitivity of fiber optic sensors as applied to leakage detection. WSN comprises motes otherwise referred to as wireless sensor nodes that are interconnected wirelessly to live and detect physical quantities like temperature, pressure, sound, video, etc.
It is low cost, reliable, available, functional in adverse conditions and compatible with other methods thus providing redundancy and reliability. Pipelines naturally span wide geographical areas and therefore need robust real-time monitoring for adequate security. The low-cost nature of WSN makes it very adequate for this task. However, power sustainability and multimedia transmission are among some challenges of WSN in meeting wide area coverage and real-time demands of pipeline surveillance. Implementing distributed architecture and data fusion in WSN design also as choosing high resource motes and good topology effectively enhances pipeline surveillance systems.
Pipeline Threats and Detection
Human threats could be available in the shape of vandalism, sabotage, operational error, and construction works. Some attacks on pipelines are caused by groups of individuals who are in dispute with Government, or pipeline operators. This might be militant groups that attack pipelines as in the case of Niger Delta, in Nigeria. Also, due to sheer greed or poverty, people resort to tampering with pipelines for private gains. Instances include the case of theft from a pipeline passing underneath Deputy Prime Minister’s house in London, and protracted cases
of pipeline sabotage in Nigeria. Moreover, there are growing concerns that terrorists might begin to use oil and gas pipelines as weapons of mass destruction. Operational errors contribute considerably to pipeline failure either thanks to system failure, or technicians and pipeline operators at work. Also, systems put in situ to watch corrosion also as Supervisory Control and Data Acquisition (SCADA) systems could fail resulting in pipeline failure. Concluding the discussion of human threats, construction work may be a major explanation for pipeline failure within the developed countries. In the USA, pipeline incidents through construction work are mitigated using pipeline right-of-way surveillance, satellite surveillance, public awareness activities and one call system. Other methods are acoustic monitoring and fiber-optic sensors
buried along the pipeline.
Deterrence of terrorists, vandals and thieves are often achieved by detecting common weapons used by these groups including explosives, guns, knives and other sharp objects. Vandals use axes, explosives and other sharp objects while thieves are likely to use drills, and containers or A Framework for Integrated pipeline Monitoring and Incident Mitigation Systems tanks to siphon fuels. Technologies wont to detect metallic and non-metallic weapons and explosives include Terahertz imaging can detect objects from a distance of 0.5km which is deemed sufficient for proactively initiating defensive actions.
Natural threats to pipelines are mainly corrosion and natural disasters like earthquakes and landslides. Pipeline corrosion is an electro-chemical process that changes metal back to ore as a result of a difference in potential between two points having a path for the flow of current which results in one among the points losing metal. differing types of corrosion are identified like uniform attack, pitting, inter-granular or exfoliation, crevice, filiform, galvanic corrosion and stress corrosion. Coating prevents corrosion in pipelines, and in most cases cathodic protection is additionally wont to further protect pipelines.
Intelligent or smart pigs are used to gather pipeline data and detect leakages and metal loss. Corrosion detection technologies available include Visuals, Eddy Current, Ultrasonic, Radiography, Thermography, Robotics and Automation, Data Fusion and Sensor Fusion. In pipeline systems, pigging and eddy current are widely used to detect corrosion. Natural disasters like earthquakes and landslides, thanks to their unpredictability, also constitute threats to pipelines. Scientists have reported the potentials of using seismic data to predict earthquakes and landslides but accurate predictions are still not possible.
Besides pipeline surveillance, other applications of WSN in the oil and gas sector include leakage detection, Tank Level Monitoring, Equipment Condition Based Monitoring (CBM), Pipeline Pressure Relief Valve Monitoring (PRV), Refineries Pressure Relief Valve Monitoring (PRV) and Wellhead Automation and Monitoring. Although most pipeline surveillance systems have focused on leak detection, few pipeline surveillance systems have tried to deal with threat detection in pipelines.
Forms of Attacks
Often, pipeline operators make new connections to pipelines to expand or modify their existing system. This usually involves a shutdown (3 days or more) of the pipeline system and purging the oil or gas to make sure a secure atmosphere. Hot tapping is an alternate process used to establish pipeline connections while the pipeline remains in commission. It's used for corrosion repairs, upgrade work or other modification works on pipelines with no downtime.
Alas, this industrial technical process is now getting used by thieves to siphon fuel from pipelines. Explosive attack is administered using explosives like dynamites, C-4, HMX, RDX, and TNT. These attacks are administered by militants, vandals, saboteurs’ terrorists or thieves. Most attacks on pipelines using explosives are done when the pipeline isn't operational. Explosive attacks administered while pipelines are operational end in fire and will claim the attackers’ lives.
Tampering attacks, as utilized in this text , ask attacks by third parties which neither involve hot taps nor explosives, still they're aimed toward stealing fuels from the pipeline. This often involves drilled holes on the pipeline, cutting the pipeline with hacksaw, or third party tampering with well head, clamps, valve settings and flanges.