GIS Support for Field Developments Projects: A Contractor Experience and Perspective
Authors: Marrannes Michel , Collins Keith , Piquemal Pascal 
Published: April 2012

Abstract
GIS (Geographical Information System) technology is now regularly used for datamanagement and data exchange of geo-science seabed survey information. Theoperational implementations of GIS in support of SURF (Subsea infrastructures, Umbilicals, Risers, and Flowlines) field development projects are howeverrelatively new. This paper presents, from a Contractor experience andperspective, the GIS applications used for several large construction projectsperformed offshore West Africa and North Sea, over the last 6 years, for avariety of Operators.
The GIS functionalities have expanded progressively, from project to project. The implementation of Web-based GIS server has been an important step forward, allowing much easier data access to non specialist project stakeholders andoffshore teams. The GIS is used during the overall project cycle, from tenderto as-built. Each stage of the project has its own requirements andpriorities.
At design stage, the main applications are for seabed assessment and pipelinerouting. Some bespoke applications have been developed, such as a " planningvisualization tool", to anticipate potential SIMOPS (SimultaneousOperations).
At offshore installation stage, the field status is changing rapidly, often ona daily basis. The main objective is then to capture the relevant informationas soon as possible, and as close as possible from the effective data source. Once validated, the data are published onto the project WebGis, which becomesthe primary project reference, used as a " live" deliverable.
At as-built stage, the main objective is to integrate all pertinent data, fromthe successive project phases, engineering, fabrication, installation, metrologies, as-laid/as-built surveys, in order to produce the final as-builtdocumentation. Within this process, a quality control and best fit analysis areperformed, as the different data sources have different positioning accuracies. The final GIS geo-database is organized with several main features datasets. The data model for the subsea infrastructures was initially aligned on thepublished ESRI APDM (ArcGis Pipeline Data Model), but a simpler data structurehas also been derived and implemented, for easier use by both the GIS engineersand final users. This can be adjusted according to the Operators ownspecifications for the Life-of-Field GIS, and also to any future industrystandard.

Introduction
GIS has been used by Subsea 7 over the last 6 years for several largeconstruction projects performed offshore West Africa and North Sea. From anas-built deliverable at the origin, to a repository for a large spectrum ofproject data, and now as an effective transversal communication tool, its usehas been constantly in evolution. It now has the capability to encompass allthe phases for the Life-of-Field, from tender to as-built, and then duringoperation support and maintenance, ultimately until decommissioning andabandonment.
From an Operator viewpoint, it has long been recognized that GIS is the optimumsolution for handling very large geographic datasets. From a Contractorviewpoint, GIS provides efficient answers to a series of requirements andissues, such as survey data management, field layout details and updatesfollow-up, project data repository, and installation process. This paper showsthe evolution of our GIS use since 2002-2005, and presents some of ours latestGIS applications and perspective in support of offshore field developmentprojects.