ABSTRACT

The development of innovative exploratory dri11ing systems for Canada's harsh Arctic offshore areas over the past decade is described. Future activity in these areas, including possible production concepts, is also discussed.

The results of the experience in Canadian waters can be applied in other Arctic areas of the world including offshore Alaska. This operating experience will serve to further advance the drilling technology and will serve as a basis for the design of Arctic offshore production and transportation systems.

Artificial islands, first commenced in 1972, are still being constructed but with improved designs and equipment. A step forward has been the use of subsea berms on which concrete or steel segmented caissons have been placed. Integrated-type steel caissons have a1so been adapted for placement on subsea berms, one of which is half of a crude oil tanker and a second, a purpose-built steel caisson to be placed this summer. Four drillships were converted and/or strengthened for Arctic service in the Beaufort Sea and three have drilled since 1976. The second generation floating vesse1 for the area is the Kulluk conica1 drilling unit which commenced drilling in 1983 and has extended the operating season. In the Arctic Islands, drilling off artificially thickened ice in water depths exceeding 1200 feet has preceded successfully, commencing in 1973. On Canada's East Coast, use of dynamically positioned vessels and iceberg towing have permitted seasonal drilling in ice infested waters.

Production of oil from Hibernia and gas from Venture are possible by the end of the decade. Production of oil from the Beaufort Sea is possible in the early nineties and from the Arctic Islands about mid-nineties. Systems for such production are discussed.

In meeting the challenge of the harsh offshore environment in the Canadian Arctic, unique technology has been developed and successfully utilized in the discovery of major accumulations of hydrocarbons. Continued advances in technology are anticipated which will have widespread Arctic applications in both exploratory and production operations.

INTRODUCTION

Drilling has been successfully conducted in most of Canada's offshore areas despite the extremely harsh environmental conditions. During the past decade, technology has been advanced very significantly particularly in the Beaufort Sea and Arctic Islands. Operating experience gained during the exploratory drilling phase is being used to good advantage in the conceptual design of production systems. Undoubtedly there will also be an evolution of technology during the development and production phase as the vast frontier reserves are exploited. Common to Canada's offshore frontier areas are the high costs and the long periods of time from discovery of oil until production. These factors present major engineering chal1enges for the design of safe, cost effective and timely exploratory and development systems. Confidence in the reservoir extent and predicted performance may permit mega development projects while uncertainties may result in a phased approach where possible.

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