Seabed Survey Data Model

The Seabed Survey Data Model(SSDM) is an industry standard for how seabed survey data is stored and managed by oil and gas companies. International Association of Oil&Gas Producers developed and published this standard at Oct 2011. Many surveys have been successfully delivered in SSDM.

The SSDM template is provided as an Esri ArcGIS geodatabase but O&G companies can define their own physical implementations of the SSDM on any specific GIS data formats, as long as those formats are in compliance with the core SSDM.

Significance

Outputs of seabed survey data usually contains CAD files, log imagery, surface grids and many other documents. Such a mix of data types makes the task of integrating existing enterprise data very complicated. Data models that are used by survey contractors before SSDM are APDM (ArcGIS Pipeline Data Model) and PPDM (Professional Petroleum Data Management). It is very difficult for both of these data models to manage their internal data.  In order to fix this specific problem, OGP (Oil & Gas Producers) proactively defines the SSDM to better manage the data.

SSDM provides a complete survey data management workflow with improved integration with geoscience software. It is an industry data model that comes with the complete software support that survey contractors can use. It enable the simple exchange of seabed survey data between two partners. E&P( Exploration & Production) company may also extend the data model to fulfill their specific requirements.

Area of Application

As of today, the main area of the SSDM's application includes

1. Sweep and bathymetric surveys (sonar scan and multi-beam)   
2. Platform and drilling hazard site surveys
3. Pipeline route surveys
   

SSDM is currently not capable of doing ROV based pipeline inspection surveys. That is the domain of the existing data model like APDM and PPDM. However this will not be a shortage of SSDM, because SSDM is expected to be use conjunctly with existing data models in order to capture the full range of acquired data and referenced data sets.

SSDM's Conceptual Model

The conceptual model is a powerful idea of SSDM; it is used to help people know, understand, and simulate what SSDM represents. SSDM's conceptual model includes class, object inheritance and other features.

Class

A class is a program-code-template of an object. It provides initial values and implementations of an SSDM object. A class can be defined as either abstract or concrete. A concrete class can be directly used to create an object. Concrete classes can be think as the Feature Classes or Object Classes in the ESRI geodatabase. On the other hand, an abstract class must be inherited in order to create a concrete class. SSDM abstract classes such as Feature, Feature Archive, and the SSDMSurveyObject describes the core attributes of a SSDM objects.

Object Inheritance

The mechanism of object inheritance is based on the idea that many SSDM classes share similar features and it would be a waste if all of them define their own version of those features. Object inheritance allows an object using the same implementation with its parent class to best reuse the code. The relationships of objects through inheritance give rise to a hierarchy.

SSDM Classes

SSDM defines tens of classes. Among them, some is more important than others.

SSDMSurveryObject

SSDMSurveryObject is the most important abstract class  in SSDM. Its Survey_ID and Survey_ID_Ref class members are used to identify the relationship for all geographic features created by a particular survey project. It define the basic data of a survey object such as type of survey, survey project name, survey work category, and start/end date.

SSDMobject

SSDMobject is an abstract class of SSDM'. It provide the basic definition of all the SSDM geographic objects.  SSDMobject uniquely identifies and describes a geographic object that is acquired, processed, or interpreted from seabed survey data, such as sounding points, and individual pockmark features. Many classes such as SSDMGeohazardObject and SSDMEnvObject are inherited from SSDMobject class therefore share the core attribute of it.

The SSDM V2 Material

The following is a list of all the materials contained in SSDM Version 2 which is published in 2013.

1. SeabedML GML data exchange format
2. CAD templates for MicroStation and AutoCAD
3. Improved SSDM symbology stylesheet
4. Refined geodatabase template (if warranted based on industry feedback)
5. Example SSDM dataset and improved training materials
6. Technical note on integrating the SSDM with industry pipeline data models e.g. PODS and APDM
   

Data Migration

The SSDM allows survey contractors to provide a standardized method for their customers but it also brings some problems. There are huge amounts of valuable legacy data stored in old standards that cannot be directly used in SSDM . In order to transfer this data into SSDM for future use, it needs to be imported into ArcGIS first and then loaded into a temporary SSDM data structure. Inside the temporary data structure, data will be cleaned up by adding the required attribution of SSDM and hyperlinking to logs and other geotechnical data. Once the data is complete and meets the requirements of the SSDM standard, it is loaded into the master SSDM database. The combination of SSDM and ArcGIS enable information contained within legacy survey data to be more accessible and much more useful.

External links

• [1]Geomatics 462 series Data models note 3