RIVER OVERFLOOD, STRUDEL SCOURS AND ICE GOUGES

Clients: U.S. Department of the Interior, Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE)

Offshore hazards to the safe development of oil and gas resources in cold regions include the unique processes of strudel scouring and ice gouging. Since 1995, Coastal Frontiers personnel have conducted annual offshore surveys to document the frequency and severity of these phenomena off the coast of Alaska. A multi-year investigation for the Minerals Management Service (now BOEMRE) sought to define the character and variability of river overflood onto the sea ice, while an analysis of measured strudel scour characteristics led to the first-ever characterization of scour zonality and the associated risks to subsea pipelines. The findings these and similar research efforts have guided the design of all three subsea oil and gas pipelines that have been installed in the Alaskan Beaufort Sea.

River Overflood, North Slope Alaska

Strudel Drain, North Slope Alaska

METHODS

Helicopter overflights during on-ice river overflood in the spring to map flood limits and individual strudel drains
Multi-beam and side scan sonar surveys to locate and quantify strudel scours and ice gouges
Integration of recent findings with gouge and scour data dating back to the 1970s
SCUBA diving and remotely-operated vehicle (ROV) operations to acquire “ground truth” information for the calibration and verification of sonar data