February 2019

What's new in exploration

The status of airguns and alternatives
William (Bill) Head / Contributing Editor

While ExxonMobil, so far, only says that it is pulling out of the GOM, BP announced plans to develop new discoveries and dig in even more investment there. Chevron says they love Tengiz and the Permian, and nothing else “new” exists for them, even after billions in attempts to secure other areas. This party is focused on cash flow, due to B.E. production issues and shareholders, more than exploration or oil price. No one understands risk, until the party is over.

This figure shows the relationship between cross-line sampling intervals and sail-line intervals for a variety of dual-source (red dots) and triple-source (green dots) towed streamer configurations. Image: Journal, GEOPHYSICAL SOCIETY OF HOUSTON, Vol. 9, No. 5.
This figure shows the relationship between cross-line sampling intervals and sail-line intervals for a variety of dual-source (red dots) and triple-source (green dots) towed streamer configurations. Image: Journal, GEOPHYSICAL SOCIETY OF HOUSTON, Vol. 9, No. 5.

A U.S. federal court in Denver, a long time ago and far, far away [from modern oceans], decided that neither pro nor cons with data could prove any damage to marine mammals from the oil industry, from ship-borne airguns, so it overruled MMS, forcing regulation intending to result in the least damage to the animals of concern [sounds innocent, yes?], by restricting access to, and conduct in, international waters. Foolishly, the U.S. Congress and Executive Branch allowed this one person’s invention of law against U.S. and international Treaties of the Sea to abrogate and control government policy and exploration activity. Other countries followed course.

The Trump administration opened the offshore U.S. East Coast and Arctic to O&G exploration, because former Interior Secretary Ryan Zinke believed politicians in robes were not using sound science. The modified reprieve of regulations surrounding exclusions to exploration under the Marine Mammal Protection Act is about to collide with the newly elected U.S. House. Only a few days in office since Jan. 1, and already, eight House bills have been submitted to stop exploration in the Arctic, U.S. East Coast, and pretty much anywhere wet USA. Airgun sound energy is the main issue claimed, and its purported effect on marine life. Of course, the ugly drillers would move in, contaminating everything.

Reality. Now, most U.S., et al, seismic acquisition has to be performed under supervision of a young person on the back deck with binoculars, looking for creatures breaching the surface; or with an expensive sonar boat using World War II analog technology reformatted into a color display. Pretty much a daylight operation during a significant part of the season out past 3-mi, or 50-mi limits. Some effort has been made to discuss improvements in both acquisition and monitoring technology, to “live within the intent of the rule.”

RPSEA and Battel formed a plan to use modern digital sonar while testing airgun alternatives in Galveston Bay, Texas. DOE awarded a $1-million-plus research contract, via RPSEA, to Texas A&M University (College Station) for testing airgun substitutions beyond land-based ponds. Battel monitoring was my add-on. Polarcus agreed to provide some ship-days for open water testing, if the research proceeded. The PGS design was not included.

The few majors partnering on the project with Texas A&M were supportive at first, until I proposed testing near real mammals in salt water. They worried that the regulation on the exclusion zone would grow or, worse, Obama regulations would be created. I argued that initial data showed zones should shrink substantially. I lost. A&M backed out of the DOE contract to study and test airgun alternatives. An industry consortium does have a website, showing some non-airgun research in hot oil places like the Bahamas and Hawaii.

Not dead. I see that Polarcus, which survived the downturn, has come up with a multi-source solution that can provide data and significantly decrease operational time. Using more than one source boat or more than one recording boat is not new. How to work data recording and timing of apertured “shots,” when towing multiple streamers, while not interfering with thousands of returning reflection amplitudes, has been the monumental equation to resolve. Combining multiple sources with the age-old problem of designaling a blended set of pulses recorded at the same time, was more or less corrected with large-scale data processing [DownUnder Geo Solutions]. Perhaps geophysicists have made a significant improvement in data while also achieving a reduction in the cost of shooting new offshore data.

I agree with the authors’ acknowledgments in total. “We thank the managements of Polarcus, and DownUnder GeoSolutions, for encouraging the development of acquisition and processing techniques, and providing vessel and processing resources to demonstrate the viability of the techniques.” I also applaud the attempt to create a court-acceptable resolution while performing a necessary industry service, perhaps even a superior marine data acquisition method, that will reduce the time that offshore exploration spends sharing the waters with marine mammals, that is, those not watching from on top of ice. wo-box_blue.gif

About the Authors
William (Bill) Head
Contributing Editor
William (Bill) Head is a technologist with over 40 years of experience in U.S. and international exploration.
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