PPDM Data Model 3.8 - WITSML Mapping

Objective

Industry members who use both the PPDM Data Model and WITSML wanted to find out whether it was feasible to create a standard mapping between the two standards. A team was formed with representatives of PPDM and Energistics to accomplish this task.

Key differences between the standards

     

> PPDM 3.8

       

> WITSML
     

The PPDM Data Model (PPDM 3.8) is a relational data model that is used for data persistence. Most of PPDM 3.8 is very explicit, with each table and column intended to store just one kind of information. WITSML is an XML data format that is designed to transfer well site information between stakeholders or processes. It is designed to allow users to exchange a wide variety of information types, and so has a more abstract design.

Each format uses different mechanisms to uniquely identify or describe objects, and to relate concepts. This means that each time data is moved from one format to the other, certain kinds of information have to be generated (such as identifiers, relationships or internal meta data). In order to do the mapping, the work group only used the elements of each standard that were expected to be moved during an exchange of information.

Use Cases

The scope for mapping was constrained to seven key objects in WITSML, and the data model sections in PPDM 3.8 required to contain the necessary information. Several use cases were defined by the working group.
  1. Use Case 1: Move WITSML data into a populated data store in PPDM
  2. Use Case 2: Transfer directional survey data between PPDM and WITSML
  3. Use Case 3a: Transfer logged while drilling data from PPDM to WITSML
  4. Use Case 3b: Transfer logged while drilling data from WITSML to PPDM

Mapping Results

WARNING: During the mapping, the team made many assumptions about how each data format would be managed, but these assumptions are not standard for all users, and are not endorsed by the owning organization. These mappings should be considered to be guidelines for use, and are not expected to be used “as is”.
Download Mapping Here >

What We Learned

What Comes Next?

We want to hear from you. Contact us at projects@ppdm.org if you have ideas or would like to talk about how to carry this work forward.

Disclaimer