1. WellPath Progress Report: Re-spudded and drilling ahead John Turvill and Paul Maton WITSML SIG, Houston TX, 9 – 11 May 2006 POSC Regional SIG, Stavanger, 13 June 2006

2. Outline Background Recent progress Current status: ‘new’ proposal Proposed plan Any other business

3. Background 2002-2003: Emergence of WITSML 1.2, UKOOA P7/2000 and POSC WellPathML specifications for well deviation data exchange Followed by requirement for only ONE specification covering entire life-cycle usage of these data, including planning and post-drilling stages –Summarised by BHI document (Andy Sentance et al., February 2004) WITSML TT issue 1.2-118 –Consideration, deferment, pending Use Cases…

4. Current approach - 1 Reviewed existing specifications and well planning software documentation Recognised similarities and differences Reconciling different vocabularies Identify the fundamental process: –depart from a known (‘key’) point with given attributes, traverse a region following given constraints to arrive at the subsequent key point

5. Current approach - 2 Provide flexible capability for varying needs Re-use existing WITSML components –Add (~<10) elements identified as needed Define profiles (subsets) of WITSML which use the wide optionality in WITSML to satisfy identified user group needs, e.g. for UKOOA P7 –Implement profiles using XSLT

6. Recent Progress – UKOOA Mapping of WITSML 1.3.1 to UKOOA/P7 and sample XML data files –Demonstrated near complete representation of P7 by sub-set of W131 trajectory and trajectoryStation –Exceptions: Planned wellbores, CRS template, DDD:MM:SS.SSS lat/long representation –Informally accepted by (2) P7 authors

7. Recent Progress - MMS MMS NTL2004-N03 defined US-centric sub-set and variant of UKOOA P7 Mapping of WITSML 1.3.1 schema to MMS NTL2004-N03 and sample XML data files –Demonstrated near complete representation of NTL2004-N03 by sub-set of W131 trajectory and trajectoryStation –Exception: Planned wellbore –Informally accepted by MMS responsibles (3)

8. Recent Progress - ISCWSA Agreement to develop and/or validate Use-cases for wellbore planning John Turvill authored the following 2 Use-cases Request to POSC / WITSML for development of WITSML conformant errorModel object –implementing SPE 67616 (Hugh Williamson, BP) in XML

9. Use Case – 1: ’Key’ Points Key points. Generate planned trajectories passing through ~10 controlling or key points. For each key point, create values for an instance of the pointDefinitionParameterSet (pDPS) with qualifiers indicating which of the controlling parameter values are instantiated, and whether each instantiated parameter value is either designed or calculated. –Source: any WITSML-aware well-planning software –Usages: by WITSML-aware well-planning software. It is anticipated that the transfer of these data between two instances of the same well planning software will be entirely round-trippable without loss of or change to any information.

10. Use Case – 2: ’Interpolated’ Points Interpolate a Set of points from and between key points such that any third party software will interpret the spatial geometry of the trajectory unambiguously. –Source: any WITSML-aware software. –Usages: by WITSML-aware software for well-planning, mechanical, geological, collision avoidance or any other purposes. It is anticipated that the transfer of the data between such software will preserve the spatial integrity of the trajectory while not necessarily conveying the full context and detail of the key points. Further interpolation of the well path using minimum curvature will not result in a significantly different trajectory or well path end location.

11. Planned Trajectory concept ‘Key’ points Point groups a.k.a ‘section’, and ‘profile’ – overloaded terms??

12. Example 1 TrajectoryStation/TrajectoryStationType Abbreviation: buildrate to INCL Documentation: Section follows a given buildrate to a specified inclination

13. Example 2 Baker / Paradigm nomenclature Abbreviation: 2DXS Documentation: A 4 section extended 'S' profile in 2 dimensions (no change in azimuth); 2D arc - 2D tangent - 2D arc - 2D tangent.

14. pointDefinitionParameterSet (pDPS) Measured depth True vertical depth Horizontal location and CRS Trajectory inclination Trajectory azimuth Dog leg severity Tool face angle Buildrate Turnrate Delta-md Delta-tvd Point creation method Interpolation method

15. Forward Plan Identify and recruit expert group Review other planning software (Compass…) Complete draft proposal Review draft proposal with expert group Revise proposal using expert feedback Revise XML assets conformant to proposal and WITSML Follow normal WITSML review / release process

16. Thank you for your attention! Questions? Discussion?