When construction planning started for a new crude pipeline across disputed territory in the Kurdistan region of the Middle East, initial research was fulfilled using high-resolution imagery sourced from satellites operating hundreds of miles above the Earth’s surface.
Reducing construction costs, as well as minimising exploration risk and improving security are all key areas in which satellites are increasingly employed by the oil industry. Plotting a pipeline route across inhospitable terrain is always a complex task, as is tracking damage resulting from deliberate acts of vandalism or natural hazards such as landslides or flooding.
Tracking developments over a particular incident, for example, illegal tapping of a crude oil pipeline, a landslide rupturing a line or choosing a route across a potentially hostile border, requires accurate, timely information for multi-disciplinary teams – oil company engineers, geophysicists and planners. Satellite technology is now a very cost-effective method of acquiring and processing images, particularly from some of the most remote and hostile parts of the world, even making it possible to source imagery through the heavy cloud cover in tropical regions or low levels of available light. With a range of resolutions available, typically lower resolution imagery and Digital Elevation Models (DEM) are used for regional planning with high-resolution data offering more detailed assessments.
Satellite imagery is digitally processed in order to accurately position the imagery and to maximise the information content of the data. Orthorectification is performed, to reduce the distortions caused by relief and many sensors offer the capability to acquire data suitable for creating DEMs that are essentially 3D representations of the ground surface. Editing can be performed to produce Digital Terrain Models (DTM), which have manmade structures or vegetation removed. DEM data can be processed to map and engineer the most direct and inexpensive transportation routes.
Image resolution (an area represented by a pixel in a particular image) can be rated as low as 50cm resolution, meaning that each pixel represents a 50cm x 50cm area on the Earth’s surface.
With such detail available, satellite imagery is now a key part of the oil companies technical armoury and is effectively used when planning a pipeline route or monitoring its physical condition.
Satellite Data Crunching
Satellites orbit the Earth in networks known as constellations, with individual satellites performing specific functions and delivering different types of data. The Geo-intelligence Programme Line of Airbus Defence and Space, for example, uses several constellations, including the Pléiades network that has the capability of acquiring imagery anywhere in the world within a 24-hour time period in the event of an emergency. The company also draws on its SPOT 6 and 7 satellites as well as the radar satellites TerraSAR-X and TanDEM-X – with resolutions across optical and radar ranging from 0.25m to 40m. It is this breadth of capabilities, which enable specific solutions to meet the complex challenges faced in the oil, gas and mining industry.
Challenges faced by engineers preparing an onshore pipeline include assessing the nature and distribution of natural vegetation and agriculture, geological variations and existing infrastructure including villages, towns or cities. Using data and imagery sourced from satellites not only provides a highly accurate overview of the planned route, it also allows the identification of subtle changes in landscape, or land-use over a short period of time (days and weeks) or much longer periods, ensuring an up-to-data situational awareness.
Significant construction projects need regular monitoring to ensure operational safety, effectively manage progress (particularly if subcontractors are involved), fulfil regulatory obligations and assess any potential environmental impact. Additionally, political and social instability, or environmental protection of local wildlife and fauna can make systematic observations of the site necessary.
Before commissioning construction, engineers face the challenge of planning a route avoiding physical obstacles and cultural landmarks whilst minimising the pipeline’s overall length. This is in addition to, security and community considerations. Satellite imagery and DEMs from both radar and optical satellites have become widely used in pipeline corridor and site selection projects, for identifying, selecting, routing and continuous development planning.
Satellite imagery can be used to derive a number of different layers of interpretation, using both manual and automated techniques. For the crude oil pipeline project in Kurdistan, detailed SPOT and Pléiades satellite data were used to derive layers, which included:
Derived terrain evaluation layers to assist construction planning:
- Contours and topographic mapping.
Derived geological interpretation:
- Identification of variations in ground conditions such as areas of bedrock outcrop or superficial deposits.
- Identification of potential geo-hazards, such as active faults and alluvial fan deposits which may represent seasonal flooding.
- Current infrastructure, to establish access routes for construction, settlements.
With the use of GIS, imagery and derived datasets can be integrated with other spatially referenced data sources for querying and assessment.
Traditional methods of pipeline planning and monitoring involve significant cost and time commitments in personnel and equipment for ground-based data collection, or the costs and potential hazard encountered with airborne survey. Satellite methods allow rapid information collection to make intelligence driven planning decisions and support field data collection at specific areas of interest, together with complimenting any in situ monitoring.
Many pipelines lie above ground and are vulnerable to human interference including theft, vandalism or terrorist attack. Being exposed to the elements also speeds degradation of the pipework and supporting structures. Natural disasters from hurricanes and floods to fires and earthquakes also regularly damage pipelines.
Many different types of oil and gas are carried though pipelines, ranging from crude oil to refined products including jet fuel for distribution at airports and marine diesel from distribution at sea and river ports. The US government’s Pipeline and Hazardous Materials Safety Administration says that for oil pipelines, potential routes are initially determined by demand patterns, including predicted required flow of crude oil from a producing field to a refinery or the expected flow of refined products from a refinery to cities and other industrial complexes. Satellite generated data can now be more effectively integrated into early project development, reducing costs and enhancing project execution. Energy companies, particularly their exploration and production departments, have long understood the benefits GIS data can offer. However, in recent times the technology has been taken up enthusiastically across other departments, realising that such imagery allows a multi-functional application.
Across important oil producing areas such as Nigeria, Columbia and Mexico, incidents of illegal tapping are common. Mexico’s state oil company Pemex reports illicit tapping of its crude oil, gasoline and diesel carrying pipelines has risen by over 20% over the past five years and cost the company $1.4billion in lost revenue in 2014. That year saw 4,127 taps discovered, up from 3,278 on the previous year. While in Nigeria, recent estimates put the loss to illegal tapping of trunk lines, which is being carried out on an industrial scale, is costing the country’s government $1bn per month. Monitoring physical conditions of pipelines is achieved in a number of ways. High sensitivity pressure monitors at the inlet and outlet of the line can detect changes in pressure that will suggest a leak. However, satellite imagery can help complement these measurements by providing supporting information.
While illegal tapping is largely caused by deliberate intervention, pipelines are frequently damaged accidentally through human activity, such as collisions with agricultural vehicles or unlicensed construction. In this instance, satellite imagery is often used to identify oil on ground post event, or potentially pre-event to assess changes which may indicate preparations for pipeline tapping or damage, such as an unplanned access road being carved through the jungle heading towards a pipeline.
Planning and safety
The latest satellite imaging is undoubtedly boosting clarity, giving planners and engineers greater insight into geographical and geological features throughout the life of a pipeline. Construction projects such as the pipelines in Kurdistan, which need planning and then, when operating, monitoring for signs of interference, are benefitting by using satellite-sourced, , time-lapse imagery to support complex engineering and security decision making.