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Seep Enhancement Algorithm
Seeps are direct evidence of hydrocarbon occurrences and are associated with many major discoveries. Seeps provide significant targets for more intensive exploration efforts. Depending on the setting (onshore vrs offshore) and degree of vegetation, MDA has a multitude of approaches to assist with finding indications of hydrocarbon seepage.
SEA is a low-cost, frontier marine exploration tool, developed by MDA in conjunction with NASA (EOCAP) to select and process satellite images for offshore hydrocarbon seep detection.
SEA operates with image data from a variety of satellites (primarily Landsat, ERS-1 and SPOT) detecting seeps under a broad range of environmental and imaging conditions.
Why Use Satellite Imagery To Locate Seeps?
Reduce Exploration Risk
- Many prospective offshore areas have yet to be searched for seeps.
- Rapidly assess vast frontier areas for hydrocarbon occurrences ahead of your competition.
- Dramatically increase the cost effectiveness of your exploration program.
- Find oil in remote, unexplored, unfamiliar and uncharted offshore areas.
Difficulties With Alternative Methods for Detection of Seeps
- Alternative seep detection methods include seismic and sonar surveys, shipboard geochemical sampling and low-altitude airborne ultraviolet surveys. High cost, bad weather conditions and access restrictions influence these methods.
- Oil slicks are difficult to see from ships
- Without a regional perspective, most oil slicks are difficult to discriminate from ocean dumping without chemical analysis.
- The ocean surface is lightly traveled relative to land.
How It Works
Finding Seeps by Satellite
- Thin oil slicks form where bubbles of oil and gas reach the surface. Oil on water spreads out thinly over a large area.
- Oil slicks affect water in two important ways that are readily detected by imaging satellites:
Spectral: oil slicks increase reflectance in the visible through near-infrared portion of the electromagnetic spectrum.
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Textural: oil slicks smooth the sea surface, reducing the amount of reflected sun glint ("glitter") and radar backscatter.
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- The type of detection (spectral vs. textural) depends on seepage rate, oil composition, sea state and illumination.
- Only satellite imagery provides detailed data on the shape and size of natural oil slicks to pinpoint seep location and estimate seepage rates.
- Other oceanographic features (pollution, aquatic vegetation, phytoplankton blooms and coral spawn) may produce slicks on satellite imagery but are easily discriminated from natural oil slicks by an experienced interpreter using SEA imagery and the SEA ranking system.
SEA: Satellite Seep Detection Features
- SEA satellite seep detection can cost less than $3/km².
- MDA's in-house global weather forecasting service allows rapid evaluation of meteorological data for SEA analyses.
- SEA requires no permits, is completely confidential and offers worldwide coverage.
- SEA's Fuzzy-Logic Ranking System quantifies the analytical process to ensure consistency and reliability.
- SEA's low cost enables repeated surveys of an area to confirm seeps and eliminate uncertain findings caused by oil spills and other transient phenomena.
- MDA incorporates global marine gravity data, derived from satellite radar altimeter measurements, to provide regional geologic context for SEA analyses.
- SEA results are rapidly integrated with gravity, bathymetry, offshore structure locations and other data to furnish complete and accurate exploration maps.
- SEA uses an adaptive processing algorithm that adjusts to data type, oil composition, seepage rate, atmospheric conditions, sea state and illumination.
- MDA experts have evaluated thousands of marine satellite images.
