Wireless Sensor Networks based Pipeline Vandalisation and Oil Spillage Monitoring and Detection: Main Benefits for Nigeria Oil and Gas Sectors

— Wireless sensor network has been applied in many areas of human endeavour since its development, especially in environment monitoring. The technology can be used to monitor pressure and temperature of pipeline carrying petroleum product, detection of oil spillage and pipeline vandalisation. Wireless sensor network has also been developed and deployed by many developed countries for other numerous applications, but it is yet to be utilized in Nigeria despite the country facing daily pipeline vandalisation and oil spillage. To ensure that the country benefits from the advantages of using wireless sensor network, there is need to enlighten organisations in oil and gas sector about the technology. This research paper specifically explore the wireless sensor network technology, types, applications, challenges and the features that makes the technology, a viable alternative in pipeline vandalisation and detection of oil spillage in Nigeria.


INTRODUCTION
ETROLEUM and its products is the mainstay of many countries' economy especially Nigeria.Since the commencement of commercial oil production in 1958 by Dutch Oil, Nigeria has witnessed a phenomenon growth in her economy [Egberongbe et al.,1].The production and growth of oil and natural gas sector are constrained by Sabotage and incessant vandalisation of pipeline carrying petroleum products.According to Society for One Nigeria, the country has lost more than seven billion dollars ($7.0bln) in revenue due to pipeline vandalisation and crude oil theft [Society for One Nigeria, 2].While Okpo & Eze [3] noted that, the use of fossil fuel such as petroleum has negatively impacted on the biosphere as it releases pollutants and greenhouse gases into the air and damage the ecosystem through events such as oil spillage.Specifically, pipeline vandalisation has led to oil spillage into the environment.The resultant effects are the loss of arable land, destruction of soil organisms and plant nutrients, and decreasing fish stock which is the main livelihood of people at the Niger Delta of Nigeria.Nigeria is considered to have the worst oil spillage and environmental pollution resulting from such activities in the world [Benedict,4].
To protest the adverse effects of oil spillage to their environment and community, Indigene of the oil producing areas and other criminally minded individuals often attack oil infrastructures, kidnap oil workers, engage in oil bunkering, causing more damage and forcing companies to shutdown oil productions with its consequent revenue loss [Egberongbe et al.,1].To ensure effective monitoring, detection and report of oil spillage into the environment, petroleum industries in developed countries and recently developing countries are now using latest network technologies to monitor pipeline to ensure environmental safety and economic growth [Imad Jawhar et al.,5].One of these technologies is the wireless sensor networks, which monitor and report uninterrupted updates and status of what is happening within and outside the pipeline installation areas.Research in computing and communication technologies has led to the development of wireless sensor networks that offer distributed sensing, which can be used for numerous applications.Some of these applications apart from pipeline and environmental monitoring are medical, military, and civil engineering and for commercial purposes [Puccinelli & Haenggi,6] There are a lot of research efforts in both developed and developing countries in the use of Wireless sensor Networks in pipeline and environmental monitoring and detection of oil spillage.These researches include development and deployment of Wireless sensor network [Ivan Stoianov et al.,7;Ning Xu et al.,8], framework for oil and gas pipeline monitoring [Imad Jawhar, 5], Deployment, security and risk assessment [Iwendi & Allen,9], Quality of Service provision and routing protocols [Bhaskar Bhuyan et al.,10], Ambient Data collection and QOS implementation in Wireless sensor Networks [Shukla et al.,11] and Energy aware routing and Quality of Service [Akkaya & Younis,12].These researches have been conducted for different applications in organisations outside Nigeria Shore.With the increasing security threat to oil and gas installations and, the human and material resources in monitoring these infrastructures, there is need for Nigeria government, agencies and companies in oil and gas sectors to think towards applying wireless sensor networks to counter the above mentioned menaces.This paper set to specifically explore the wireless sensor network technologies, applications and the driveable benefits of using this technology to combat pipeline vandalisation and secure oil installations in Nigeria petroleum industry.

II. OVERVIEW OF WIRELESS SENSOR NETWORKS
As stated earlier, researches in microelectronics mechanical system (MEM) technology, computer science and communication has given rise to the development of cheap and low powered sensor nodes that can communicate wirelessly in short distance.These devices are made up of sensing capabilities, communicating components and data processing; leverage the idea of sensor network based on collaborative effort of different nodes [Akyildiz et al.,13].Wireless sensor networks are the collection of self-powered sensor nodes that coordinates to perform some specific tasks.The sensor nodes gather information or detect special events and send the data to base station to be processed.The technology is made up of three main elements.There are target sensing, processing the gathered data from the field of applications and communicating the processed results to the user [Puccinelli & Haenggi,6].data from the networks and process the data which is communicated to the user.They may query the sensor nodes for events of interest. Agents: The wireless sensor network agents generate events of interest and transmit them to the nodes.Egea-lopez et al., [14] stated that sensor agent may cause variation in a physical magnitude which can be propagated through the environment and simulates the nodes.The agent is useful in the implementation of independent behaviour of the nodes.

Node Model
Wireless sensor nodes are divided into four abstract tier models [Egea Lopez et al.,14].They include:  Protocol tier: Comprises all the network communication protocol layers such as MAC layer, routing layer and application layer. Physical tier: This represents the hardware components such as the set of physical sensor, energy module and mobility module and their effects on the performance of nodes.The composition of the physical tier depends on the applications.Physical hardware describes how the monitoring hardware behaves, the energy module simulate the power consumption of the nodes while the mobility module control the physical positions of the nodes.
 Media-tier: Media tier is the link connecting the individual nodes to the physical environment.The link maybe a radio channel or physical channels such as micro wave, radio wave or infra-red and cables respectively.Typical structure of wireless sensor network is shown in figure 1 below.

Types of Wireless Sensor Network
According to Jennifer Yick et al., [15], there are different types of wireless sensor networks available depending on the environment where they are deployed.They included terrestrial, underwater, underground, multi-media and mobile wireless sensor networks.This section of the research paper will explain extensively these types of wireless sensor networks and their application in environmental monitoring and target tracking.i.
Terrestrial wireless sensor networks: These consist of thousand of cheap wireless sensor nodes deployed in a geographical area in ad hoc or pre-planned manner.Ad hoc deployment allow sensor nodes to be dropped randomly on the location of interest while pre-planned deployment, nodes are placed in grid, optimal, 2dimesional and 3-dimesional models.above can be minimised within the network through the development of transmission techniques that support high bandwidth and low energy consumption.
To enhance the quality of service provisioning in the network, and ensure reliable content delivery, innetwork processing, filtering and compression need to be adopted.Also, cross layer interaction among the layer can improve the processing and delivery process.Table 1 below lists the different types of wireless sensor network, applications and the challenges hampering their deployment and acceptance.

Applications of Wireless Sensor Networks
As stated in the

Home Application
 Integration of smart sensor nodes and actuator into home appliances such as vacuum cleaner, microwave ovens, refrigerators and video players that can interact with each other internally and externally through internet to allow users to manage home devices remotely.

Commercial Applications
 Environmental control of office buildings where a distributed wireless sensor networks integration can be used to control air flow, temperature and to reduce energy consumption. Can be deployed in museums to provide paging and locations in the museums. Wireless sensor nodes are being deployed in cars to help detect and identify threats within geographical area and report these threats to remote end user for proper analysis. Structural health monitoring system for detection and localisation of damage in building, bridges, ship and aircrafts [Ning Xu et al.,8].

III. PIPELINE VANDALISATION AND OIL SPILLAGE MONITORING: WIRELESS SENSOR NETWORKS AS VIABLE ALTERNATIVE
The wireless sensor network technology has established itself as a viable alternative in target monitoring and detection.The use of human resources and security agencies (Police, civil defence and military) in pipeline monitoring and detection of oil spillage has become a huge burden on the government due to the expensive nature of the system.Even the alternative sensing technology such as oil spillage trajectory model which is a model that predict the number of days it will take oil spill to get to the coast line of Nigeria proposed by Egberongbe et al., [1] has not save the difficult task.They pointed out that, it will take an average of 5.5 days to detect oil spillage at Nigeria coastline.This is long time for destruction of huge magnitude to occur in the environment.
Another techniques that has been deployed by oil and gas industries in Nigeria [Egberongbe et al.,1] is the establishment of Nigeria Sat-1 Satellite that provides oil spillage position and serves as oil spill model inputs.There was also the creation of regional spill response centre along coastline but this has not provided the best method in oil spillage monitoring.The use of wireless sensor networks in target monitoring has gained prominence in recent years.These include wireless sensor network for steamflood and waterflood pipeline monitoring developed by SunHee Yoon et al.,- [17], oil and gas monitoring in the United Arab Emirate [Imad Jawhar, 5], Development of Wireless sensor networks for detection of topological changes [Farah et al.,18] to mention but a few.Nigeria can tap onto these developments and applications of wireless sensor network to monitor oil and gas infrastructure and promptly detect and respond to damages in pipeline carrying petroleum products.There are number of reasons why wireless senor networks have been deployed in target monitoring.This section of the paper will explain the advantages of wireless sensor networks over other traditional sensing technologies in pipeline vandalisation monitoring and oil spillage detection in Nigeria.
Stanlava [19] in his research on the application of wireless sensor networks, noted that four technologies have driven its application and acceptance.These technologies include Radio Frequency Identification (RFID), Global Positioning System (GPS), General Packet Radio Service (GPRS) and Wireless Local Area Networks (WLAN/802.11).Wireless sensor networks rely on existing low powered Radio Frequency Identification services.RFID is widely used for device tracking and to keep track of sensor nodes deployed in oil and gas fields.To ensure effective location of target such as leaking pipeline, vandal positions and exact location of existing defective infrastructure, wireless sensor networks deploy emergency response application, Global Position system (GPS) with camera as a supporting technology.Data collected by wireless sensor network can be appropriately presented over the internet using the General Packet Radio Service (GPRS).This enhances the time it takes to transmit data to appropriate decision maker to take actions.Stankovic further noted that the data can be transmitted over the internet through wireless local area network (WLAN/802.11)while the same data can be presented to mobile phone format using Bluetooth technology.
Autonomy is another attractive feature of wireless sensor network technology [Chanin & Hollaran,20].When the nodes are deployed in oil and gas field, the microprocessor can automatically initiate communication with other nodes to form wireless mesh networks and relay information to each other through the central node.The above feature has made wireless nodes to be deployed in any location.
Other advantages of wireless sensor networks as enumerated by [Chanin & Hollaran,20;Huen & Sohu,21] which has made it sought after technology in target monitoring and detection are:  Uses inexpensive and low-powered microcontrollers and transceivers making it affordable to many organisations. The mesh networking employed to transmit data from one point to another consumes less energy than the traditional sensing technology. Ad hoc nature of the network allow addition of wireless nodes when required [Bhattacharyya et al.,22]. The technology offer better coverage than centralised sensing network as more wireless nodes can be deployed in large area. Considerable reduction in data loss due to remote sensing and monitoring, and data are collected in realtime. Negative environmental condition cannot affect pipeline monitoring as that can be done remotely especially in inaccessible area. The technology can allow many user to view and manipulate the data transmitted simultaneously as data are retrieved from remote site.The data can be automatically analyse and appropriate action taken when phenomenon of interest occurs. Sensor nodes are self-healing, nodes can be added or removed without bringing the network to a halt.The network can reconfigure itself and determine the best route to the base station.This is important if any node die during vital operation.The above feature and advantages derivable from the application of wireless sensor networks has expose the reason behind the adoption of this technology as a veritable tool in infrastructure monitoring.Organisations in oil and gas and environment has deployed this important development, and Nigeria cannot be an exception to this.There is need to enlighten industrial player, government and researchers on the benefits of wireless sensor networks in pipeline vandalisation monitoring and oil spillage detection.This will enable these organisation to appreciate the technology and work towards its implementation.

IV. CONCLUSION AND FUTURE WORKS
The effects of pipeline vandalisation and oil spillage in the environment are enormous.Despite its negative consequences, it is a frequent occurrence in Nigeria.
Monitoring of pipeline infrastructure is a costly task, therefore devising a more effective means that is less expensive is very important.Wireless sensor networks which has been used in other countries to monitor and detect defective infrastructure.To obtain timely information on pipeline vandalisation and oil spillage can help in mitigating their negative effectives on the environment.This research has effectively outline the benefits of using wireless sensor networks in oil and gas sector in Nigeria.Further research of this work will look at the implementation requirement, implementation and development and quality of service provisions for wireless sensor networks, deployed for pipeline vandalisation and oil spillage monitoring and detection in Nigeria.

table above
Monitoring of pressure and temperature of pipeline carrying petroleum products [Imad Jawhar et al., 5]. Detection of oil spillage, pipeline vandalisation, leak and rapture in water supply and pipeline block to reduce maintenance cost [Ivan Stoianov et al., 7]. Deployed sensor nodes can be used to detect forest fire and relay the exact location and origin to the base station to enable quick intervention.