Assessment of Safety, Risks and Costs Associated with Subsea Pipeline Disposals

摘要

When a subsea pipeline reaches the end of its useful life, due to economic or mechanical integrity reasons, it must be abandoned or removed. If abandoned the subsea pipeline owner remains responsible for the pipeline even though it is not in service. Currently, subsea pipelines are de-inventoried and purged until the hydrocarbon levels are undetectable before abandoning them in place or the pipeline is de-inventoried and purged until the hydrocarbon levels are undetectable before recovering the pipe as scrap. The common practice in both the U.S. waters and the North Sea is to abandon the pipeline in place. This report presents an overview of the current U.S. and International regulations and details the safety risks, environmental risks and costs associated with the various disposal options for pipelines, which are no longer in use. Scandpower Risk Management Inc. (Scandpower) of Houston, Texas carried out this study for the Minerals Management Service (MMS) and the Department of Transportation (DOT) Research & Special Programs Administration Office of Pipeline Safety (RSPA/OPS). Scandpower has subcontracted Global Industries to assist with identifying the removal technology and developing the cost estimates. For this study the most common method of disposal for subsea pipelines, abandoning the pipelines in place, was used as a baseline and several removal options currently used around the world were compared with this base case. The disposal options used in this report are documented in The Abandonment of Offshore Pipelines Methods and Procedures for Abandonment by John Brown Engineers and Constructors.