The Arctic offshore is still considered by some exploration geologists to have high potential for future discoveries. The great optimism of the early 19705, however, has been replaced by a more cautious view that marginal fields may be the discovery of the future for the Alaskan offshore. At a time when the price of oil has fallen to a record low and on shore Arctic 0il fields may start running In the red marginal field concepts take on added significance. The recent completion of an Arctic offshore well by Amoco Production Co., successfully drilled from a low cost "spray ice Island" In 25 ft. of water, emphasizes the practicality of the concepts described- In the paper. - The senior author has spent ten years working on Arctic offshore exploration and development concepts with major emphasis on marginal field and low cost techniques. The paper briefly reviews the background and describes recent developments in the field of marginal techniques for the Arctic. Of greatest Importance, it shows how these techniques have great promise for being extended for use in deep water dynamic Ice conditions for both exploration and production in the Arctic.
A great deal of knowledge has been gained during the last decade on Arctic offshore environmental conditions and in particular sea ice. In addition, a large number of actual drilling operations, in all types of ice conditions ranging from mild nearshore ice to highly dynamic shear zone ice have provided invaluable operating experience and insight. This availability of sea Ice statistical data, proven real time ice surveillance techniques coupled with accurate short term Ice prediction techniques and the Insight from actual operations has now made it feasible to safely embark on second generation, extremely low cost, marginal approaches to exploration and production in the Arctic offshore. The potential savings that can be achieved from these concepts are extremely large and are estimated to range from $30,000,000 to $100,000,000 per well .At a time when oil prices are at an all time low and the profits from on shore Arctic fields are extremely small the marginal field concepts become extremely important. The successful completion only a few months ago by Amoco Production Co. of an Arctic offshore well, drilled from a "spray ice is land" constructed in 25 ft. of water, illustrates the practicality of the concepts described. Early marginal field work for the Arctic offshore concentrated on the "support structure" and its resistance to Ice loads. Recent work has shown that there is a complex web of interrelationships between structure type, proposed site locations, drilling depths, number of wells in a program (Both per year and total for the program), distance from major shore bases and the necessary transportation support required for the concept.
