The Loss of the Sleipner A Platform

Abstract

Offshore installations are complex and expensive engineering structures that are unique in terms of their design and operational characteristics. Over the past three decades, there have been major advancements in the technology used to extract oil and gas, which has enabled exploration to extend to challenging and hostile environments, including the Troll field in the Norwegian sector of the North Sea. The Sleipner platform was the first of three concrete gravity base structures to be used to extract oil and gas from this field, and great effort was placed on a timely start-up of gas deliveries in order to ensure the credibility of Norway as a reliable European energy partner. The gravity base structure (GBS) of the Sleipner platform was the twelfth in a series of GBS platforms of Condeep-type designed and built by the company Norwegian Contractors in Gandsfjorden near Stavanger, Norway. On August 23 1991, during a controlled ballasting operation in preparation for deck mating, the Sleipner platform sank. All 14 people onboard the platform was rescued by nearby boats without injuries. The failure involved a total economic loss of about 700 million dollars. Safety is a major concern for all offshore operations and a proper risk management plan is critical in ensuring a safe and successful project. Risk management involves the identification of hazards associated with a specified activity in order to minimize the probability of their occurrence, and/or mitigate their consequences. Risk management is particularly important in hostile ocean environments such as the North Sea, where even the most routine and simple tasks could result in great consequences should trouble strike. The following paper will discuss the sinking of the Sleipner A platform and explore the investigation that took place immediately following the disaster. The paper will also discuss the coastal facilities required to construct Condeep platforms, as well as the role of risk management in the process. Finally, the impact to subsequent offshore structures following the Sleipner platform sinking will be assessed.