Subsea survey for positioning and soil investigation is one of the main activities for subsea field development. As part of the planned field development, a detailed geophysical and geotechnical field development survey together with soil investigation is performed.
The purpose of the survey is to identify the potential man-made hazards, natural hazards, and engineering constraints of a proposed subsea field area and pipeline construction; to assess the potential impact on biological communities; and to determine the seabed and sub-bottom conditions.
Subsea survey scope
Subsea surveys typically include the following tasks:
- Establishing vertical route profiles, a contour plan, and the seabed’s features, particularly any rock outcrops or reefs;
- Obtaining accurate bathymetry, locating all obstructions, and identifying other seabed factors that may affect the development of the selected subsea field area including laying, spanning, and stability of the pipeline;
- Carrying out a geophysical survey of the selected subsea field and route to define the shallow sub-seabed geology;
- Carrying out geotechnical sampling and laboratory testing in order to evaluate precisely the nature and mechanical properties of soils at the selected subsea field area and along the onshore and offshore pipelines and platform locations;
- Locating existing subsea equipment (e.g., manifold, jumper, and subsea tree), pipelines, and cables, both operational and redundant, within the survey corridor;
- Determining the type of subsea foundation design that is normally used or subsea field development.
- Subsea Engineering Handbook by Yong Bai and Qiang Bai, Publication Date: January 27, 2012 | ISBN-10: 0123978041 | ISBN-13: 978-0123978042 | Edition: 1