Mapping WITSML datatypes in ISO 15926

Meeting participants:

Kari Anne Thorsen - UiS, Nejm Saadallah - IRIS, Lars Overå - UiO, Martin Skjæveland - DNV, Johan Kluewer - DNV, Henning Jansen - NOV (partially present)

Purpose of meeting

The initial purpose of the workshop was to map generic xsd datatypes and schema structure in ISO 15926, which was deduced from the need to categories and identify WITSML base types and witsml schema structure. The WITSML schemas (available from http://www.witsml.org ) are using core XSD types, routed through one single WITSML schema, the typ_baseType.xsd schema. The typ_baseType.xsd schema defines all abstract base types for WITSML, which are all derived from xml simple data types, directly or through other WITSML abstract types. This raised the question on whether it is the purpose of ISO 15926 to be able to identify and categories xsd datatypes and schema structure.

The workshop concluded that it is not the responsibility of ISO 15926 to represent the structure of xsd schemas. This structure is standardised and conducted by W3C, and it is W3C responsibility to maintain and update the standard. A mapping in ISO 15926 require constant attentions on update and changes and can easily lead to inconsistency between the standard and ISO 15926 representation of it.

Thus, ISO 15926 should not catch the schemas structure of WITSML, but it should be able to catch the semantically structure and interpretation of concepts in WITSML. E.g. the interpretation of the concept well bore and that a well bore must belong to a well.

To accomplish this there is still a need to be able to identify what a WITSML base type represents. E.g. a witsml:abstractBoolean is an representation of a boolean value. Thus, ISO 15926 should be able to identify WITSML representation of abstract concepts like integer, boolean, string etc.

PCA SIG Work processes

The meeting also had a session with a debate over the work process used by SIG's actively creating and maintaining a set of ontology. A few conclusion's was made:

• A XML file format for declaring ISO-15926 is promoted by the IQM dept at DNV/Høvik. This format is expected to be used by the SIG by the end of January 2008.
• A graphical tool to create visualizations of the above mentioned XML files is promoted by the IQM dept at DNV/Høvik. This tool is expected to be used by the SIG by the end of February 2008.
• The SIG will arrange an internal workshop session in January where the new XML file will be demonstrated, and the Subversion work-process will be established.