In the world of seismic datasets, marine seismic is the gold standard. “Almost as good as marine” is the highest compliment that can be paid to a land survey. But trouble has been brewing in paradise.

For years the sound source for marine surveys has come from airguns, which emit instantaneous large volumes of air, making a noisy, explosive-type bursting sound. Unlike other seismic technologies that need updating or changing due to obsolescence, there is nothing wrong with airguns from a technical standpoint, according to Bill Head, ultradeepwater manager for the Research Partnership to Secure Energy for America (RPSEA).

“Present-day difficulties with airgun use have little to do with geophysics or sufficiency of energy,” Head said, “but with compliance with U.S. court-determined opinions resulting in regulations surrounding the interpretation of the 1972 Marine Mammals Protection Act. RPSEA has been seeking to test seismic source alternatives as it relates to good seismic signal, exploration productivity and safe use within current or future regulation.”

Anyone familiar with marine seismic knows the tale—regulators and nongovernmental organizations have become increasingly vocal in their opposition to the use of airguns, resulting in somewhat onerous requirements such as having a marine mammal observer onboard all working vessels to look for the presence of marine life and also the use of passive acoustic monitoring systems to detect mammal activity in the area of a shoot.

Despite scientific studies that show no real evidence of negative impacts on marine mammals, the industry has shouldered these regulatory burdens and done its part to “save the whales,” so to speak. But it also has been busy behind the scenes looking for an alternative to airgun sources.

RPSEA and others have been examining this concept in detail. The RPSEA concept is a joint industry project (JIP) to manage and test at least two “marine vibrators.” An independent JIP sponsored by ExxonMobil, Shell and Total contracted with PGS, Applied Physical Sciences and Teledyne Webb Research to develop and test marine vibrators. In 2012 this JIP asked RPSEA to include these designs in its tests. The RPSEA project, which kicked off in September, is expected to last two years and fund demonstration trials of two newly developed marine vibrators.

RPSEA also is considering other designs, including one created by the original inventor of the airgun. Each trial will use a full-scale full-power prototype, yielding data on both performance and reliability. The objective is to find a marine source that can provide the type of seismic illumination to which the industry has become accustomed. Deliverables will include data made available to the geophysical community, regulators and science-oriented environmental organizations for evaluation.

BP and CGG also are planning to collaborate in an R&D project on new types of “marine vibratory seismic sources,” according to a press release, and are in fact hoping to improve on technical performance while also focusing on environmental sensitivity.

It’s nice to see the industry so actively engaged in this type of research. “Being good stewards of the oceans is a natural thing,” said Jacques Leveille, senior vice president of technology and communications for ION. “To that end, we’ll continue to evolve and improve our source technologies so that we’re meeting the needs of the industry in an environmentally safe way.”

Contact the author, Rhonda Duey, at rduey@hartenergy.com.

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