Seabed survey datasets are assets of enormous value for offshore operators. Environmental, site, geo-hazard, debris and pipeline planning surveys catalogue features on and below the seafloor to support well planning, drilling and production operations – all expensive and potentially risky activities. Identifying hazards on the seafloor that can jeopardise these operations is of particular importance to operators. It is vital that such data sets should therefore be accurate, easy to use and easy to share. Recent crisis events such as Macondo and Elgin illustrate why a business should ensure this data is managed properly.
The data management challenge
The challenges with survey data stem from the wide variety of outputs produced when acquiring the data. Typical survey outputs comprise CAD files, log imagery, surface grids and many other documents. Managing such a mixture of data types can be very difficult. The task of then integrating these existing enterprise data is therefore far from straightforward.
Example Seabed Survey Data in ArcGIS
A new model, but what about old data?
In 2011, the International Association of Oil and Gas Producers (OGP) released the Seabed Survey Data Model (SSDM). The objective of the model is to improve the framework for managing and utilising seabed survey data, which had previously been difficult to manage due to the lack of an industry standard for doing so. The SSDM is a great model for new data, and one of its key benefits is in providing a standardised method for survey contractors to provide data to their customers. But what about the high value legacy data sets which were not originally captured in the SSDM standard?
Migrating legacy data into the SSDM standard
At Exprodat we realised that companies could derive great benefit from migrating their legacy datasets into the SSDM standard so we developed a series of workflows to do just that. Legacy survey data comprising CAD, GIS, tables, images and other documents is imported into ArcGIS and then loaded into a “staging” SSDM data structure. This data is then cleaned up by providing the required attribution and hyperlinking to logs and other geotechnical data. Only once the data is complete and meets the requirements of the SSDM standard is it loaded into the master SSDM database. This is shown in the diagram below:
Schematic Workflow for Migrating Legacy Data into SSDM
Now our clients can incorporate legacy data into the SSDM format so that the value of these important data sets can still be realised.
SSDM and ArcGIS
SSDM helps resolve data management and system integration issues by using ArcGIS as the information system platform. Data standards promote data integrity through table and format definitions and there are numerous data management tools in ArcGIS which are adept at encouraging such standards. Esri’s ArcGIS software is widely used throughout the industry for mapping and analysis so data integration with other corporate data sets is relatively straightforward, and ArcGIS’s popularity means that survey data and information is also easy to share with business partners.
Using ArcGIS to Manage Seabed Survey Data
Simplified data management
The SSDM organises survey data into 30 vector feature classes split across Environmental Samples, Seabed Features, Shallow Intermediate Geology and Survey Measurement feature datasets. Bathymetry Digital Elevation Models, Side Scan Sonar Images and Backscatter Images raster datasets can be stored in their own Raster Catalogs while Channel Surfaces DEMs and Geologic Surfaces DEMs fall into the Shallow Intermediate Geology feature class. Finally, a Survey Jobs Details table is used to record basic survey information.
Key information is validated through the use of controlled lists of subtypes and attribute domains. Standard cartographic symbology is linked to controlled attribute fields allowing rapid and consistent thematic classification of SSDM features. Each data set has a number of attribute fields for storing detailed metadata. The Survey Key Sheet feature class, for example, records survey dates, survey type and contractor details. The consistent and organised SSDM framework means that data management is immediately more efficient than using previous methods.
The SSDM Framework
Simplified data access
Another useful benefit of the SSDM is that the full functionality of ArcGIS is available. Multiple surveys can be displayed in the same map and a standard symbology can be applied to the data wherever it is used throughout the enterprise. Attribute data can be subjected to complex queries to allow users to easily find the data they need. Hyperlinks within the data tables allow imagery and log reports to open within ArcMap adding another layer of information. Seafloor and shallow surface data can be modelled in 3D and existing enterprise data can also be added.
The combination of SSDM and ArcGIS enable information contained within legacy survey data to be more accessible and much more useful. Since the release of SSDM in April 2011 Exprodat has gained considerable experience incorporating legacy data into the data model and then integrating that data into an enterprise GIS.
For further information on how Exprodat can help you adopt the SSDM to add value to your business please contact us using the form below this blog.
Posted by Nathan Mooney, GIS Consultant, Exprodat.