Measurement of the Transverse Movement of Sea Floor Gas Pipelines

A problem has been identified, where in the transverse movement of gas pipelines in the North Sea must be monitored for a five-year period. The motivation behind this study is a requirement placed upon the pipeline owners to ensure pipeline integrity. Engineering and operational requirements suggest a deployment range for a sea-floor unit of about 100 m from the pipeline. Self-alignment of transducers, surface interrogation and freedom from diver support, together with mechanical robustness to guarantee immunity from damage by trawling equipment are also required. The paper describes the results of a pilot study undertaken to determine the suitability of a proposed acoustic method for achieving these ends.