Error Model Documentation
Latest Version - Revision 5
At the 50th ISCWSA meeting in Calgary, in October 2019 the error model maintenance committee approved the release of version 5 of the ISCWSA error model. Various improvements to the modelling were made at this time based on analysis of available data and on the best judgement of the members of the committee.
Feedback on this release can be sent to the error model committee chairman.
The documents defining and supporting this revision 5 release are as follows:
Release Notes
detailing the main changes in this release.
Rev5 Management Presentation (added 16/9/22)
a Powerpoint document designed to help educate management about the changes and advantages of Rev5.
Error Model Definition Document (updated 20/1/23)
the complete definition of the error model which has been updated to reflect these changes.
XCL Term - Technical Supplement (updated 16/9/22)
a document describing the specific changes made to XCL terms and borehole misalignment.
Correlation of Geomagnetic Reference Terms - Technical Supplement (updated 06/10/23)
a document describing the specific changes made to the generic geomagnetic reference terms. There is an associated spreadsheet with the calculations to breakout the terms.
Definition of the Primary Categories of Geomagentic Models
A document defining what constitutes a Low, Standard, High Definition, IFR1 or IFR2 geomagnetic reference model.
Diagnostics for the Application of the Correlated Geomagnetic Reference Terms
an Excel spreadsheet containing example anti-collision results between pairs of wells, with and without the application of the geomagnetic correlation. Various geometries and combinations of MWD+SRGM and MWD+IFR models are considered.
MWD Rev5 Diagnostic Files (updated 23/9/22)
A set of covariance diagnostic for the model on the three ISCWSA test wells.
(Note. At this stage these have been created by A.McGregor and the format varies slightly from previous diagnostics created by Steve Grindrod)
MWD Rev5 Spreadsheet Examples (updated 5/1/23)
A set of Excel spreadsheets which enumerate MWD Rev 5 on the three ISCWSA test wells.
ISCWSA Generic Set of Toolcodes Rev5-1
These are a default set of conservative tool-codes for use when tool specific models are not available. They are also referred to as the OWSG models.
ISCWSA_Generic_Toolcodes SetA Rev5-1 (updated 23/9/22)
ISCWSA_Generic_Toolcodes SetB Rev5-1 (updated 23/9/22)
Recommended Practices
Recommended practices produced by the error model committee:
Recommendations for Management of Inclination Only Wells
Recommendations on the Handling of Sidetrack Wellbore Clearance Scanning (added 16/9/22)
Lexicon
Although this document was produced by the collision avoidance committee it also contains the defintions relevant for error modelling.
Archived Error Model Documentation
Additional Archived Error Model Documentation can be found here.