DynaMAC: Molikpaq ice loading experience

• Main Authors: Hardy, M., Jefferies, M., Rogers, B., Wright, B.
• Format: Report
• Language: English
• Published: National Research Council of Canada 1996
• Subjects: Canada; Beaufort Sea
• Online Access: https://doi.org/10.4224/12328378; https://nrc-publications.canada.ca/eng/view/ft/?id=9475864c-6e0d-4f70-9fc8-5747787f915d; https://nrc-publications.canada.ca/eng/view/object/?id=9475864c-6e0d-4f70-9fc8-5747787f915d; https://nrc-publications.canada.ca/fra/voir/objet/?id=9475864c-6e0d-4f70-9fc8-5747787f915d

This report to the National Energy Board presents a compendium of ice loading events experienced by the Gulf Canada Resources Ltd. offshore platform "Molikpaq". To date, the primary interest in the Molikpaq has focused on a single event (the 0800 hr ice loading event on April 12th, 1986 at Amauligak I-65) which has perhaps led to some unbalanced views about the response of the Molikpaq during its four deployments in the Canadian Beaufort Sea. The intent of this report is to make the ice mechanics community more aware of the range of ice-structure interactions and ice load levels that the Molikpaq has experienced during the four winter deployments. Four winters of operation at four different locations have produced an enormous amount of data, far more than can be realistically used within a research context. However, much of the ice interaction data are similar. An objective of the work carried out for this report was to review the available information and filter out about 30 days with events which capture the key aspects of Molikpaq icestructure interaction and for which the available information is suitable for further research use. Icestructure interaction events where ice failed directly against the caisson are of most interest and are available from the first two deployments at Tarsiut P-45 in 1984/85 and at Amauligak I-65 in 1985/86. At these locations the Molikpaq was deployed at a setdown draft of 19.5 metres, which resulted in no permanent accumulation of rubble ice around the caisson. A total of 10 operating days at Tarsiut P-45 and 19 operating days at Amauligak I-65 have been selected that contain representative periods with both ice documentation and Molikpaq instrumentation response data. A further objective of this study is to summarize how the reported loads were derived from the sensor data, and to address concerns about potential structural resonance and overall load estimate accuracy. The Molikpaq was deployed for hydrocarbon exploration and the acquisition of the ice structure interaction ...