Hijacked ARIS 13 Oil Tanker Urgently Located with Pléiades Satellites

Issue at Stake

By combining the Automatic Identification System (AIS) and the Pléiades satellites, Airbus located the ARIS 13 oil tanker attacked by Somali pirates in less than 4 days.

Challenge

On 13 March 2017, Somali pirates captured the ARIS 13 oil tanker and its eight Sri-Lankan crew members.

The tanker was transporting bunker oil from Djibouti to Mogadishu when it was attacked by armed men aboard two skiffs. The vessel’s capture was the first successful hijacking of a commercial vessel by Somali pirates since 2012.

Once onboard, the pirates cut off all communication and positioning pieces of equipment, including the AIS emitter that regularly transmits the vessel’s identity, position, and course.

When it lost the AIS signal from ARIS 13, CSO Alliance asked Airbus to programme the Pléiades satellites to find the vessel.

“It is the willingness of Airbus to engage at speed and provide accurate and relevant output in times of stress that is helping shape our relationship. This valuable data combined with other information sources we share not only with our CSOs to better protect their crews, but the Military as we work to develop a two-way dialogue with the CSOs of the Merchant Marine.”

Mark Sutcliffe. Director CSO Alliance

Solution & Results

The Pléiades satellites were programmed using the vessel’s last AIS positions. Reports suggested that the oil tanker had travelled west to the east outside the MSPA corridor in the Gulf of Aden.

The first image was programmed on 14 March, the day CSO Alliance raised the alert, based on ARIS 13’s last known positions. The image was made available the next day, on 15 March.

To obtain a satellite image in 24 hours, the Pléiades satellites are programmed in Premium One Day mode. The team of maritime experts at Airbus analyzed the images, located and identified the vessel. ARIS 13 was not identified on the image of 15 March 2017, indicating that it had been diverted to another port.

The satellites were therefore re-programmed on other ports along the Somali coast. ARIS 13 was identified the next day on a new Pléiades image, north-west of the port of Abo. Its length, width, and shape matched the vessels’ technical characteristics.

Benefits

  • Once notified, CSO Alliance informed its network.
  • During the night, the coast guards from Puntland commenced negotiations with the pirates and the vessel was freed.
  • Acting within the framework of Operation Atalanta, the French frigate Courbet established contact with the crew. It adopted a friendly approach to providing medical assistance to one of the seamen. The frigate then escorted ARIS 13 to the Somali port of Bosaso.

Solution Description

The Vessel Report Service provides ship information reports based on satellite imagery acquisitions, as one shot or on a regular basis. The basic level of information provided is a mere ship detection report; it can optionally be enriched with ship classification, identification and activity detection.

Organisations Involved

CSO Alliance Maritime is a global community, covering all maritime regions and sectors. They are mobilizing an online community of over 400 Company Security Officers from more than 40 countries in a secure porta, allowing CSOs to connect, inform each other of risks they face and, through structured information exchange. This organization gathers key stakeholder and the military, support their security planning and actions to more effectively counter maritime crime.


Challenge

Relocate an oil tanker hijacked by pirates in an emergency.

Solution & Results

Combining the Automatic Identification System (SAT-AIS), Airbus’ satellites rapid acquisition capacity and analysis expertise, ARIS 13 oil tanker was located in a few days.

Benefits

Support decision-making with actionable intelligence and understanding of the situation remotely.

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Data Portal – Our New ESRI Streaming Software

Data Portal – Our New ESRI Streaming Software

Good news for all oil and gas clients using ESRI software, Airbus now offers the Airbus Data Portal, an online data delivery and access system, which is based on ESRI serving technology. The fully compatible service enables customers to stream products and services directly to their desktop, web or mobile devices.

Click here to enquire about the portal

Data portal
Data portal

For example, one product streamed through the Data Portal is the Global Seeps database, which is a non-exclusive subscription service. The Global Seeps database of offshore oil slicks is derived from both archived and newly acquired satellite data. The data is used as a cost-effective risk-ranking tool prior to new exploration projects or used to support environmental baseline studies, to understand where seeps might occur naturally.

Cost-effective Offshore Monitoring Service Geared to Protect Your Assets and the Environment

Oil leaks need to be detected as soon as they happen. Remotely acquired satellite images offer a cost-effective way to continuously monitor offshore assets. Airbus operates an unrivaled satellite constellation, which includes the TerraSAR-X radar sensor, which has the unique capability to acquire suitable images to enable detection of oil slicks regardless of the time of day or cloud coverage.

Airbus is now able to offer an offshore “insurance” monitoring service where radar imagery is regularly captured over a particular site or group of sites, whilst the full resolution imagery is only supplied when a particular incident occurs or following a specific request, enabling long-term cost-effective monitoring. This monitoring service is supported by Airbus’ specialist oil and gas team, who have extensive experience in interpreting oil slicks and spills from radar imagery using visual assessment for both exploration and pollution studies and are therefore able to provide an assessment as soon the image becomes available. Interpretation is based on the principle that radar waves are able to highlight the dampening effect oil has on the ocean’s surface.

An insurance monitoring project is undertaken using a two-phased approach:

Phase 1 – Screening

Airbus downloads a reduced resolution quick-look of the captured image. The scene is reviewed and a summary report map including the quick-look is issued, identifying any suspected anomaly or confirming that no further action is required. The report is typically delivered within 24 hours of image availability, with options for a faster service if required.

Phase 2 – Detailed Interpretation

If an anomaly is found in Phase 1, Airbus will respond to a client request for more detailed interpretation of the imagery. The full resolution scene is downloaded and a second summary report map is issued with the interpretation of the scene at full resolution. Delivery of the full report is typically within 24 hours of the request, with options for a faster service if required.

A number of delivery options are available including email, FTP or the Data Portal.

Current Projects

Airbus is currently undertaking a one-year project which involves twice monthly monitoring of an offshore site with ongoing hydrocarbon production. Radar imagery offers a significant advantage enabling image acquisition even during cloudy days. The remote nature and regularity of the service have the added advantage that less staff are required for site surveys and the interpretation of the findings, whilst the data provides the reliable overview needed to ensure the immediate environment around an asset is safe.

AAPG

SEG and AAPG, the recognised global leaders in the dissemination of high-quality geoscience data and information, launch their International Conference and Exhibition (ICE) in London, 15-18 October,  2017. AAPG/SEG ICE London will present professionals from different fields.  From geologists, geophysicists to other petroleum industry professionals from 60+ countries to demonstrate and share their knowledge and skills, discover technology innovations and communicate with fellow professionals.

We will be exhibiting our oil and gas portfolio at this year’s event and we look forward to meeting you!

Visit us at Booth 325.

Enhanced Satellite Imagery Supports Offshore Oil Spill, Security Monitoring

Michael Hall

Airbus Defence and Space

Observations using satellites orbiting thousands of meters above the Earth allow energy companies to regularly monitor sites for oil spills and leaks, without the costs associated with conventional monitoring techniques.

Satellites have a range of applications relevant to offshore operations including providing telecommunications between platforms and shore-based controllers and navigational data for positioning offshore vessels. Over the past couple of decades, the quality and agility of image sensors mounted on earth observation satellites, and the associated image processing technology, have improved substantially.

From the first seismic study commissioned for an oil or gas prospect to the final day of a field’s decommissioning, satellite images can make a significant contribution to the monitoring needed to make sound decisions concerning oil and gas-related assets. Especially since many of these facilities are in remote, hostile, environmentally and culturally sensitive locations.

Satellites now offer image resolution down to at least 50 cm while the time taken between image capture and delivery is continually being reduced. Also, as satellite technology has improved, so has the range of application areas including offshore assessment of seabed habitats and bathymetric mapping. Current sensor technologies are enabling enhanced clarity underwater, offering sight up to around 100 ft (30 m) in clean water, which is important for example, in tropical waters.

A recent satellite-based pollution monitoring program involved use of the TerraSAR-X radar satellite over the Persian Gulf. This led to accurate mapping of ship and rig locations, with potential slicks classified into three pollution confidence levels based on context and morphology. The entire process of image acquisition, processing, information extraction, map production, and delivery was completed within 24 hours.

Offshore Angola

A group of satellites operated by Airbus Defence and Space were recently tasked to complete a pilot test for institutional interests in an evidence gathering trial of its constellation’s capability. Twice daily, over an 11-day period, satellites passed over an offshore region in Angolan waters covering several thousand square kilometers, including all the country’s major producing fields such as Girassol, Tulipa, and Bengo.

Using a combination of radar and optical data gathering, all offshore activity including that of fixed facilities, drillships, support vessels and tankers, was imaged and identified. Oil slicks were also documented and classified. Both the optical and radar constellation were leveraged, adapting the tasking strategy to the weather conditions: radar satellites, for example, when weather conditions led to thick cloud cover or optical satellites for the highest resolution imagery when clear weather conditions allowed high visibility.

Analysts used optical images from the Pléiades satellite to identify ship traffic entering the area around production vessels, and to classify whether this was tankers, support vessels, or drillships. The Pléiades satellite’s optical capability was also used to assess ongoing activity such as water discharge, flaring, and helicopter movements. In addition, certain time-sensitive and irregular offshore activity could be analyzed, such as degassing.

During the trial an oil slick was identified from images taken by the SPOT 6 satellite, with the slick tracked to an FPSO. Through accurate, regular imaging it was possible to plot the course and progress of the slicks. Bespoke maps were compiled showing slick locations and related features. A classification system was also applied to assist in determining the probable source of the pollution, for example whether it was a natural subsea oil seep or from a leaking riser or flowline. The slick classification was based on various characteristics including morphology, size, location, direction of flow, and context.Analysts used optical images from the Pléiades satellite to identify ship traffic entering the area around production vessels, and to classify whether this was tankers, support vessels, or drillships. The Pléiades satellite’s optical capability was also used to assess ongoing activity such as water discharge, flaring, and helicopter movements. In addition, certain time-sensitive and irregular offshore activity could be analyzed, such as degassing.

The combination of radar and optical surveillance tools, proved particularly effective. Radar satellites, such as the TerraSAR-X operating in Wide Scan SAR, are effective for leakage detection over large areas of open sea based on the mirroring effect oil slicks have on the water surface, as waves are dampened by the oil presence. Optical sensors can identify the smallest items in high resolution.

Security scenario

In addition to the environmental risk associated with routine operations, offshore and near-shore infrastructure and facilities are vulnerable to malicious acts. These attacks have the potential to cause oil leaks from drilling rigs, FPSOs or platforms, posing risks to offshore personnel as well as potentially significant environmental and commercial impact.

When armed militia groups attacked oil refining and storage facilities in Tripoli, Libya’s capital, fears quickly grew that many of the millions of barrels stored on site could spill. Airbus Defence and Space was commissioned to use its satellite-based Instant Tasking service to provide high-resolution imagery of the facility. Within 90 minutes of the satellite passing over the selected area, a high-resolution image became available to planners working thousands of kilometers away, allowing swift, time-sensitive decisions to be taken.

Airbus Defence and Space is launching a 24/7 emergency response subscription service, enabling customers from the upstream sector to obtain access to satellite imagery in response to the many potential emergency scenarios that may occur, from terrorist attacks to accidental oil spillage. The service makes use of pre-trained staff experienced in satellite tasking procedures to give customers access to the company’s range of satellites.

Subscribers also receive data interpretation and planning for ongoing monitoring in the aftermath of an emergency.

 

Read the article in the Offshore magazine

The Sky is Not the Limit – Pipeline Monitoring

Any number of facility and pipeline accidents or incidents is too many. They can cause major business disruption, significant environmental damage and, in some cases, human fatalities. In the U.S. alone there were more than 30 incidents in 2016, and each of these instances increased the pressure on business owners and operators to improve the design and maintenance as well as inspection management of their assets.

However, help is at hand. The availability of new advanced satellite technology, software and sensors is enabling businesses to monitor assets using a more holistic, integrated approach, generally described as asset integrity management (AIM). To function effectively and to accurately inform operators about plantrelated network issues, precise and up-to-date data are crucial. Gaining this insight requires the appropriate tools to be in place to constantly monitor assets, which can span several hundred kilometers. This is where commercial access to satellite innovations and premium satellite operators’ oil-and-gas-specific intelligence and expertise provides new, valuable datasets to support and cost-effectively inform operational AIM activities.

Advanced satellite innovations for AIM strategies

Very high-resolution and wide-swath satellite sensors already have proved to be successful tools, especially when assets are located remotely, allowing oil and gas operators to monitor facilities and pipelines in a timely manner, no matter how far away these infrastructures might be from management or decision makers. Many satellite providers also have given oil and gas operators direct access to tasking their constellation of satellites. One of these providers is Airbus Defence and Space, which not only gives access to its satellites but also offers value-added services and intelligence solutions, supporting each stage of the oil and gas project life cycle.

Optical sensors such as the Pléiades satellite constellation take very high-resolution images in fine detail (Pléiades offers 50-cm imagery products). The other sensor type is a highly sensitive radar sensor such as TerraSAR-X. Radar images, for example, are very suitable to help detect offshore oil leaks regardless of the weather or light conditions by identifying the dampening effect oil has on sea surface waves. Equally, complex civil engineering projects, which can cause movements of the Earth’s surface, use TerraSAR-X-based analysis to detect even the smallest changes to ensure the safe implementation and maintenance of infrastructure constructions, excavations and underground engineering.

When selecting a satellite imagery provider, operators should ensure they choose a partner that has access to the full gambit of radar and optical satellite constellations and has user-friendly platforms in place to facilitate quick satellite tasking and dissemination. This is particularly important when urgent and timely images of an area of interest are required. In addition, the satellite provider’s expertise in responding to oil- and gas-specific needs and challenges should be an important aspect of the selection process.

An asset’s design stage

AIM is focused on ensuring that a particular asset or group of assets is performing its required function effectively and efficiently while also protecting HSE. From initial design stages satellite imagery and intelligence can play a valuable supporting role, helping to inform key planning and construction decisions, which can have long-term implications.

Satellite technologies have for decades helped advance the geological interpretation of onshore and offshore regions to evaluate potential areas of development. Beyond this, they can support the projects’ further development.

For example, onshore satellite imagery-based maps are used to assist the seismic planning process. The images allow mapping “go” areas, which are areas that are easily accessible, and “no go” areas, which don’t allow seismic acquisition vehicles to easily collect data. This simple process can substantially reduce the time the staff needs to spend onsite for data collection, and it also reduces the multiple risks team members are exposed to when moving around the world, particularly in difficult-to-reach and inhospitable locations.

In addition, Airbus also offers a number of satellite- based elevation products, including a worldwide homogeneous elevation map named WorldDEM. Using this dataset in conjunction with satellite images gives engineers detailed information to develop optimized construction routes, locations and appropriate designs, which can help increase an asset’s efficiency and safety from an early stage.

In one recent example ILF Consulting Engineers needed detailed information to calculate an optimized, fast and cost-effective pipeline route traveling between Georgia and Azerbaijan. Due to the short lead time of the project, Airbus was tasked with providing data for the project prior to construction with a required accuracy level of 1-m (3.2-ft) root mean square. Initially, very high-resolution Pléiades archive imagery and off-the-shelf digital elevation models and elevation datasets were provided that allowed ILF to verify the pipeline corridor position and correct prerouting errors; this was then advanced with new acquisition of Pléiades stereo pair datasets and onsite acquisition of ground control points that provided a highly accurate Elevation 1 Digital Terrain Model, helping identify a shorter route than initially considered as a result (Figure 1).

All of this was successfully planned and engineered remotely on a computer with the provided datasets. This enabled the team to ensure compliance with numerous factors, which overall minimized risk and cost during the construction stage and during the pipeline’s operational phase, minimizing site data collection.

The benefits are equally significant in an offshore scenario. Airbus’ One Tasking satellite service provides an important tool for monitoring the environmental impact of construction work, enabling early interventions if required. In a recent example, the environmental impact of nearshore pipeline construction activities was monitored in the Caspian Sea using satellite imagery to identify the impact of dredging activity on the dispersion of sediments. Traditional water quality monitoring techniques would have presented logistical and operational inconveniences as well as long processing times, whereas with flexible satellite tasking capability images were delivered just 2.5 hours after acquisition. This allowed the customer to define the quantitative and spatial dispersion of sediments and make rapid, informed decisions based on the findings.

Monitoring during the production phase

The continuing depression of global oil prices and the resulting reductions in budgets have led to the lifespan of many operational assets being extended to maximize return. The increasing age and potential structural vulnerability of these dated assets brings along a whole host of new challenges for AIM, but even new assets require rigorous maintenance and continuous inspections to guarantee that their condition is “fit for service”—all requirements that can be supported by satellite imagery and its derived intelligence.

In contrast to other imagery acquisition tools such as airplanes and helicopters, satellites offer data acquisition that is significantly more cost-effective since the satellites already are circling the globe and no expensive equipment or experts are required onsite, particularly useful when long pipeline stretches need to be monitored. The satellite-produced datasets can be used to plan maintenance checks and infield monitoring activities more precisely or to increase the efficiency of infield operations. They also can be used to identify pipeline leaks or structural changes in almost real time to enable rapid action to be taken.

Some satellite providers also offer the automated detection of imagery changes using historic and up-to-date satellite imagery. Airbus’ automated change detection software can provide valuable insights and prewarning information for integration into AIM systems.

Emergency detection and response

It is not only structural issues or the lack of maintenance that can cause problems. Illegal pipeline tapping, vandalism, terrorist attacks or unintended attacks caused by geopolitical conflicts are major threats for oil and gas assets, presenting an ever-evolving danger that is difficult to manage. In one example, Pléiades was tasked when a fuel storage facility in Libya caught fire during conflicts between rival militants. By using Airbus’ GeoStore, the Pléiades satellite constellation was tasked and very high-resolution images were received just 90 minutes after the satellite passed the area, quickly providing fresh and important
information regarding fire source points and nearby areas that were at risk as well as details to plan any response (Figure 2).

The process of tasking a satellite to retrieve exactly what is needed has now become even easier with the launch of One Tasking, which only requires a few clicks using this online platform. The flexible service also provides the option to create regular tasking plans in line with client-specific AIM system milestones, which means the satellite can be scheduled in advance to capture a specific area of interest on the exact day(s) required.

Should the AIM system detect an emergency issue, the first priority is to get the right information to the right person. Satellite communication tools, which also track asset locations using a geographic information system, provide an efficient way to communicate important action plans and share datasets across global team members, enabling an appropriate response to issues. SAFECommand is an example of this type of satellite communication tool, providing a secure platform that provides real-time location intelligence for staff and vehicles as well as integrated operational planning, response and communication functionalities.

Satellite technology—advancing AIM

The availability of the latest satellite technologies provides a unique opportunity to gain important insights into an asset’s safety and environmental impact throughout its life cycle and at an affordable cost. Moreover, the addition of intuitive satellite tasking services, the environmental monitoring capability of radar satellites, automated change detection and satellite-based communication tools can all be used in isolation or integrated into a suite of resources available 24/7 to maximize an operation’s effectiveness and to benefit the organization.

Read the article in the E&P Magazine

East Africa Oil & Gas Week

Visit us at stand 8, at the 6th East Africa Oil and Gas Week to discuss our unique offer for the Oil and Gas industry.

This year’s East Africa Oil and Gas Week will explore issues such as the region’s latest licensing rounds, offshore security, transparency and accountability, operating efficiency and local content.

Meet our team and find out about products such as WorldDEM, Global Seeps, Remote Monitoring, Geological Studies, amongst much more.

View the official event page

How Airbus Defence and Space’s Satellites Advance the Monitoring of Ageing and Decommissioned Assets

Michael Hall, Senior Geologist at Airbus Defence and Space explores how satellite-monitoring services can address the challenges faced during the decommissioning stage of an asset’s life cycle.

Oil and gas assets, in the final stage of their operational lifecycle, present a whole host of challenges for oil and gas operators. The decommissioning of mature assets requires a demanding amount of resources, involving cost, time and personnel.  Offshore assets, which are typically located in remote locations, can be particularly challenging, as they don’t allow project managers and other related personnel to oversee facilities and their potential environmental impact regularly. Additionally, even after decommissioning, an asset has associated environmental and security risks that make long-term, continual monitoring a necessity for conscientious operators. This article will explore how advanced satellite monitoring and surveying technologies can address some of the challenges faced during the twilight days of an asset’s lifespan.

Advanced Satellite Technologies

A number of satellite providers have in recent years given oil and gas operators access to their range of high-resolution and wide-swath satellite sensors. One provider, Airbus Defence and Space, not only gives access to its satellites, but also offers value-added services and intelligence solutions, supporting each stage of the oil and gas project lifecycle. More recently, these satellite-based services have developed into reliable, accurate and user-friendly tools, assisting oil and gas decision makers with valuable and timely intelligence when facing challenges and managing projects.

There are two key satellite types with different capabilities – optical sensors, such as the Pléiades satellite constellation, which takes high-resolution images in great detail (50cm resolution). The other sensor-type is a highly sensitive radar sensor, such as the TerraSAR-X satellite constellation. Radar sensors have the capability of detecting oil leaks offshore, regardless of the weather or light conditions, by identifying the dampening effect an oil slick has on surface waves, providing a highly effective tool to detect environmental issues offshore.

Monitoring ageing assets

Energy infrastructure is built to last for a project’s lifetime. However, as offshore infrastructure operates in extremely challenging environments, assets are exposed to extreme conditions, which cause corrosion and can lead to structural instabilities. This is why ageing assets require constant monitoring and maintenance to minimise the risks faced by the operator’s team and the surrounding environment.

This type of risk can be further exacerbated when operators extend the working-life of assets to exploit their productivity. A recently published Lloyd’s Register whitepaper stated that up to 70% of the world’s energy production, including nuclear, chemical and petrochemical industries, rely on matured assets. In addition, the Asset Integrity Service’s Senior Vice President, Ken Bruce recently highlighted that “the oil and gas industry, as a whole, is trying to delay premature decommissioning in order to maximise the economic recovery of the UKCS (United Kingdom Continental Shelf) as there are still production gains to be realised from many of these assets at the late stage of the lifecycle.” The extended use of matured assets coupled with tighter margins and operators’ mixed portfolios of assets which are normally at very different lifecycle stages, illustrate the industry’s need to identify most cost-effective and flexible inspection methods.

The increased resolution and commercial availability of satellite imaging meets this demand, enabling the cost-effective monitoring of offshore assets on a constant basis. Satellite-based monitoring has the advantage that decision makers can comfortably task image acquisitions directly from their desktop, retrieving information without having to send expensive experts or related team members to the site. This allows managers and engineers to oversee a number of rigs simultaneously, providing valuable information about a rig’s condition, which also enables the efficient planning of more detailed inspections.

The Pléiades satellite constellation’s 50cm resolution offers the ideal imaging technology to monitor assets or assist the planning of inspection activities. Striving to make satellite tasking easier and quicker, Airbus Defence and Space’s new ‘One Tasking’ service has been developed, which allows tasking the high-resolution Pléiades constellation amongst other sensors, within minutes, with an unprecedented guarantee to deliver only the most useful results.

The decommissioning stage

When an offshore site’s production ceases and matured assets enter the decommissioning stage, satellite technologies provide cost-effective support to oversee the decommissioning process and monitor environmental implications.

According to Decom North Sea, a not for profit organisation working to minimise decommissioning costs, there are more than 600 offshore oil and gas operations of varying size and a network of more than 10,000km of pipelines in the North Sea. Many of these structures have been producing oil and gas for over 40 years. The growing numbers of installations which will have to be taken out of service, require effective environmental monitoring technologies and effective project management throughout their decommissioning stages.

The decommissioning process of an offshore facility can take several years, based on numerous factors, including the structure’s age, water depth, platform type, weight, weather and the applicable laws. As each country and region has its own legal and taxation regulations for the decommissioning process, coordinating a global network of resources and sites can be challenging and the right, cost-effective tools can make a difference.

Once it has been decided if the infrastructure is to be partially or wholly removed, satellite imaging can be used to plan the following decommissioning activities.

One Tasking’s sub-product, OnePlan can be scheduled to take up-to-date images of each decommissioning milestone, providing practical detail to decision makers on the project’s progress. OnePlan gives you guaranteed and qualified coverage within an agreed timeframe. You can task the service online, selecting your timeframe, dates and preferred sensor and the Airbus Defence and Space team ensures you receive the right qualified coverage, which perfectly matches your project milestones. Regardless of the One Tasking service selected, the 24/7 access to the sensors and the provider’s guarantee to deliver useful results make satellite tasking risk-free and highly effective, which is in great contrast to the industry’s previous ‘best effort’ approach.

Environmental monitoring

Radar satellite technology is one of the key tools to monitor environmental implications. For example – if a pipeline is damaged during decommissioning activities, radar sensors can pinpoint any resulting oil pollution on the sea surface. The images can then help to understand the leak’s source point, providing crucial information for emergency response planning.

Regardless of the selected decommissioning solution, which could, for example, mean that the structure is left in situ, sunk to the seabed or that only the structure’s upper part removed, regular monitoring is necessary to ensure the site is safe, complies with all relevant regulations and doesn’t have an environmental impact. The introduced remote radar technology is a reliable and cost-effective tool to fulfil environmental survey requirements, without the need for operators to visit the sites or incur additional costs, such as taking water samples of the decommissioned site.

Conclusion

The article has examined available optical and radar satellite sensors, as well as new services, such as the satellite tasking service One Tasking and environmental monitoring products from Airbus Defence and Space. The suggested satellite technologies dramatically reduce the need for on-site staff, providing cost-effective intelligence to assist the decommissioning process.

Read the article in offshore technology

Supporting Exploration With Satellite Imaging Technology

Author: Michael Hall, Senior Geologist, Airbus Defence and Space

Satellites are a recognised method for gathering data remotely and understanding surface characteristics of both land and ocean, providing a unique insight when developing hydrocarbon reserves.

Gathering such satellite derived Earth Observation (EO) data offers focused geospatial intelligence to support oil and gas projects as they progress from exploration, through development, production down to decommissioning stage.

Applications relevant to exploration include geological interpretation, infrastructure and vegetation mapping, terrain assessment and the identification of natural oil seeps. A key benefit of using satellites is the effective targeting of field surveys and seismic collection.

Additionally, the use of EO data is particularly relevant where exploration is occurring in remote areas with difficult or hazardous access, where personnel, equipment or the environment may be put at risk during field activities.

Latest satellite technology

Utilising EO data for supporting exploration activities has increased in recent years in parallel with the technological progression in satellite sensor technology, coupled with the use of satellite constellations where two or more satellites with similar capabilities are operated together.

These advancements have led to greater spatial, spectral and temporal resolution giving an increase in detail that can be discerned, the number of spectral bands over which information can be collected and the frequency at which an image can be obtained.

Optical and radar satellites 

Satellite systems for EO centre around two main categories: optical and radar.

Their primary characteristic is their spectral and spatial resolution depending on the specific sensor, with a range of pixel sizes from tens of metres to less than half a metre.

Many of the optical satellites allow multiple images to be acquired from different angles as the satellite passes over a target area in order to produce a Digital Elevation Model (DEM), which is a three-dimensional representation of the ground surface. A DEM can be processed to calculate slope angles and interpreted to identify geomorphological and structural features.

Optical satellites typically operate in the visible and near-infrared part of the spectrum. However, they can have extended multispectral capabilities acquiring data in a number of wavelength bands not visible to the naked eye, giving additional insight into vegetation and lithological characteristics including mineralogy.

These multispectral bands are typically acquired at coarser resolutions than the visible wavelengths.

Whereas optical satellites rely on reflected or emitted electromagnetic radiation initially sourced from the sun, radar sensors on satellites are active and send pulses of microwave energy to the earth’s surface and record the return signal.

Individual radar sensors, such as TerraSAR-X, operate at a particular wavelength and offer high resolutions down to 0.25 metres. These sensors are independent of cloud coverage, sensitive to identifying surface characteristics including texture and geomorphology, whilst also allowing DEM generation. 

Satellite base datasets

Satellite imagery and DEMs can be considered as key base datasets for EO oil and gas applications, from which a number of value-added products and services can be derived.

Imagery used for oil and gas applications typically range from around half a metre resolution for detailed studies to 15m resolution for more regional applications.

In terms of elevation data, available DEM datasets include SRTM and ASTER GDEM with 30-metre grid spacing and are typically suited to regional studies.

Increasing in accuracy and resolution, commercial DEMs include the recently released WorldDEM™, a global elevation model at 12 metre grid spacing, allowing more subtle terrain features to be identified.

Radar derived DEMs can be generated using radargrammetry or interferometry techniques with grid spacing of approximately 10 metres and are particularly applicable in areas where frequent cloud cover would limit an optical approach.

Where higher resolutions and accuracies are required, bespoke models at 1m grid spacing can be generated using very high resolution stereo satellites, giving the greatest accuracy levels with the use of surveyed ground control points.

The value of EO data in supporting oil and gas exploration is in the interpretation and analysis applied to the base imagery and elevation models, including geological interpretation and seismic planning as outlined in the following sections.

Geological interpretation and assessment

An understanding of surface geology is valuable in screening areas for exploration and targeting seismic acquisition and fieldwork more effectively.

Many areas of exploration have a lack of existing geological mapping at a suitable scale or accuracy, with prospective structures potentially absent or inaccurately positioned. In addition, locations may be challenging to access for logistical or security reasons, which makes the targeting of field surveys particularly relevant.

The use of EO data for geological interpretation is well established and can be performed at a range of scales, from regional down to an individual license block or structure. Regional studies may be undertaken on a multi-client basis and are available for many key regions and exclusive studies over individual licence blocks.

For example, the East African Rift System can be viewed as an exploration hotspot with onshore discoveries in the Albertine Rift and Turkana County, Kenya and offshore discoveries in Tanzania and Mozambique. Here, a regional multi-client geological study covering approximately 4.5 million square kilometres is providing exploration companies with a consistent onshore geological interpretation of structure and stratigraphy. This together with the identification of oil seeps on the rift lakes and offshore, forms an important baseline of information to support exploration.

The primary source of this information is satellite derived, including radar data for identifying slicks on water-bodies, as well as optical data and digital elevation model (DEM) data for onshore geological interpretation.

In a new study Airbus Defence and Space assessed the nature of the petroleum-rich Zagros region in Iran using remote sensing data for a detailed fracture reservoir study. The study includes detailed mapping and analysis of the distribution, intensity, relative geometry, continuity, connectivity and structural settings of structures and faults for seven sub-areas selected across the region, together with major structural features of the Asmari Formation’s reservoir quality of fractured carbonates.

Analysis and interpretation of satellite imagery is now almost exclusively undertaken in a digital environment, using image processing software and geographic information systems (GIS). Geological interpretation from remote sensing data of structural features, stratigraphic boundaries and superficial geology relies on the assessment of a range of image and elevation model features including geomorphology, spectral signatures, texture, vegetation and drainage patterns. Although the primary information source is the available EO datasets it is important that remote sensing geological studies are undertaken in reference to existing mapping, any field data and published information.

A typical structural interpretation would include the capture of features such as dip and orientation of bedding surfaces, surface trace of major and minor faults, their classification and indication of relative sense of displacement. Fold axial surface trace of fold structures, sense of vergence and direction of fold plunge can also be identified.

Assessment of fracture orientation and density is often carried out as part of analogue studies where target reservoir rock may outcrop in other parts of the basin outside the licence block.

Quantification of dip and strike values is possible where sufficiently detailed DEMs are available and the target area contains suitable structurally controlled geomorphological features. Algorithms have been developed which combine, for example, digitised bedding planes, represented by ‘flat iron’ features and elevation values to calculate approximate dip and dip azimuth values, assisting with three-dimensional modelling.

Lithological discrimination can be based firstly on the visual pseudo-colour appearance on the imagery, using non-visible parts of the electromagnetic spectrum and relating the appearance to existing geological maps, and secondly through further analysis such as band ratios which give a certain degree of mineral identification. Mineral identification capabilities are linked to the available spectral information, with capabilities generally increasing with the number of spectral bands over which a sensor is collecting data.

EO sensors with suitable spectral bands in the Short Wave Infra-Red (SWIR) are preferred due to the particular absorption characteristics of different minerals in this part of the spectrum for lithological discrimination. However, textural and geomorphological features can also assist in mapping lithological units and particularly when vegetation cover is dense. In cases of dense vegetation more emphasis is placed on techniques, which emphasise these variations in terrain and texture, such as the use of enhanced elevation models and radar data.

In desert areas, sand cover can obscure the underlying geology and structurally controlled drainage patterns and in this situation longer wavelength radar data can be used to gather information on the shallow subsurface.

Seismic planning

Controls on positioning seismic acquisition relate to the nature and distribution of a range factors including geology, terrain, infrastructure and land use and these influences, can be assessed with the support of satellite-sourced information. In order to understand the spatial variation in slope angle, representations of the terrain in the form of DEMs are used to assess potentially accessible areas.

Land cover information is required to assess areas that are environmentally sensitive, or potentially hazardous, with the aim of reducing risk and minimising the impact of seismic collection. Hazardous areas include areas prone to flooding, subsidence or instability such as sand dune migration or mass movement.

In addition, insights into the frequency of previous flooding events can be established from archive satellite data. Equally, an understanding of the distribution and extent of habitation and agricultural activity can be used in survey planning to minimise the impact on local populations.

Quantitative analysis of variation in terrain and land-cover and the interaction between them allows a more accurate understanding of the factors influencing seismic planning. In order to effectively assess multiple geo-information datasets appropriate to seismic planning, GIS is increasingly used, offering the functionality to combine and weight individual data layers to aid the establishment of optimum routes.

Ultimately, satellite imagery and derived elevation models are making an important contribution to reducing risk at each stage of the oil and gas project lifecycle including exploration, with a range of capabilities suitable to specific environments and requirements. This is particularly important in times of falling oil prices and the industry’s ongoing efforts to increase operational efficiency.