First Successful Subsea Pipeline In The Arctic: Northstar
AbstractDue to the growing demand for oil and gas in the world, there is an increasing interest to explore new areas for petroleum production. According to a United States Geological Survey, the Arctic Circle has 90 billion barrels of undiscovered oil which represents 13% of the undiscovered oil in the world. Therefore, the development of offshore oil and gas resources in the Arctic has gained a renewed interest in the last decade. However, there are many challenges associated with design, construction and installation of arctic subsea pipeline. Some of the technical design challenges of the arctic pipelines encounter are ice gouging, permafrost thaw settlement, strudel scour, and upheaval buckling. According to literature review, BP Exploration Alaska’s Northstar pipeline has set a baseline by operating safely for the last 13 years and has demonstrated that offshore arctic pipelines can provide safe and reliable oil and gas transportation system. Northstar is the first Arctic offshore development connected to shore by subsea pipeline. This is located about 10 km (6 miles) northwest of Prudhoe Bay in about 12 meter of water. Northstar oil flows to the Trans- Alaska Pipeline System through a subsea pipeline. The primary load conditions controlling Northstar pipeline design and trenching requirement were ice gouging and permafrost thaw. The industry can apply this experience on other pipelines in arctic that has potential ice load conditions. The paper reviews main challenges in the Arctic, design criteria and lesson learned relating to the Northstar offshore pipelines for protection from ice gouging that can be considered for future offshore Arctic pipelines.
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