Pipeline Shore Approach Design: Case Study

Abstract

n insight is provided into the design of a large diameter high pressure gas pipeline shore approach for an LNG project off the coast of North Western Australia. The shore approach is located in a challenging and congested area, within one of Australia’s busiest ports. In close proximity to the pipeline route are two existing high pressure gas pipelines, several major shipping channels, a large spoil ground and environmentally sensitive coral reefs. Throughout the design process, careful consideration has been given to environmental and heritage constraints. In the case of the pipeline shore approach, prevention of coral mortality due to dredging induced turbidity has been a key priority. Ensuring the preservation of the heritage site adjacent to the landfall site has also been a major consideration. This paper describes the numerous challenges faced in designing the pipeline shore approach. A description of the design processes used to develop the secondary stabilisation and accidental external impact designs is provided. The unique methods employed to install the trunkline system across an operating shipping channel are also described. The information provided in this paper can be applied to the design and development of numerous pipeline shore approaches in the future. Individuals interested in pipeline secondary stabilisation, impact protection, shore crossings and pipelay techniques will also find this paper of value. This paper contributes to the technical knowledge base of the offshore industry by displaying the benefits of effectively combining relevant theoretical approaches with state of the art physical model testing methods and best practice installation techniques. This work demonstrates how innovative design practices can be successfully applied to produce a safe, cost effective and robust pipeline shore approach design in a challenging area.Copyright © 2011 by ASME