Arctic ice islands
The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1) calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.
- Research Organization:
- Alaska Univ., Fairbanks, AK (USA). Geophysical Inst.
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- AC21-83MC20037
- OSTI ID:
- 6091444
- Report Number(s):
- DOE/MC/20037-2939; ON: DE91002027
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
03 NATURAL GAS
54 ENVIRONMENTAL SCIENCES
ALASKA
OFFSHORE PLATFORMS
ICEBERGS
MARINE SURVEYS
SAFETY ENGINEERING
AGE ESTIMATION
ARCTIC OCEAN
BEAUFORT SEA
CHUKCHI SEA
COASTAL REGIONS
CORIOLIS FORCE
DRAG
FLOW MODELS
FLUID-STRUCTURE INTERACTIONS
HAZARDS
ICE
IMPACT STRENGTH
MITIGATION
MONTE CARLO METHOD
MOTION
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PROBABILITY
PROGRESS REPORT
RESEARCH PROGRAMS
RESOURCE DEVELOPMENT
SIZE
SYNTHESIS
THICKNESS
VELOCITY
WIND
DIMENSIONS
DOCUMENT TYPES
ENGINEERING
FEDERAL REGION X
GEOLOGIC DEPOSITS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
SEAS
SURFACE WATERS
SURVEYS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
540310 - Environment
Aquatic- Basic Studies- (1990-)