Innovative data analysis algorithms and workflows developed by the Centre for Exploration Targeting within UWA's School of Earth and Environment have recently been released as a module for the leading downhole data processing and management package WellCAD. We anticipate that this will significantly improve the speed and quality of processing of downhole images in the minerals and petroleum industries. The algorithms and workflow have been in development by the Geophysics and Computational Analysis group at the CET since 2008, leading to a collaboration with Rio Tinto from 2010 to 2013, followed by a partnership with Advanced Logic Technology (developers of WellCAD) funded by a UWA Pathfinder grant. This release follows the CET's success in commercialising the CET Grid Analysis plugins for Geosoft's Oasis Montaj.
The new Image and Structure Interpretation (ISI) workspace for WellCAD 5.1 provides auto-picking functionality and an accompanying workflow to rapidly and objectively process downhole acoustic and optical televiewer images, and formation micro-imager images. These images allow a geologist to see the walls of a borehole using different sensing techniques. In the minerals and petroleum industries, downhole image logs are routinely analysed to detect planar structures, which is of importance for understanding subsurface geology including mapping mineralisation and fluid flow pathways, and for stability calculations. Planar structures appear as sinusoids in these image logs, and their detection and analysis is challenging for industry as hundreds of kilometres of logs are collected annually. Structure picking is also subjective, leading to inconsistencies in geological interpretation.
The collaborative research between CET and Rio Tinto focused on developing new robust automated feature detection algorithms along with workflows to allow efficient use of automation in the decision making process of end users. This workflow harnesses geologists' experience while embracing the power of automation in allowing large quantities of data to be processed rapidly. The objective nature of the algorithm improves the consistency of the resulting data, and the results are repeatable.
The ISI workspace tools include: an image complexity measure which summarises the geological complexity and the image quality (which may vary due to the drilling method used or the presence of mud or sediment) of regions of a borehole, for use in partitioning a hole into geological zones; an algorithm for automatically detecting structures (including detection of half- and full-sinusoids, open and closed aperture, faint and well-defined structures) and providing a confidence value for each structure; tools for rapidly selecting structures interactively according to their structure confidence; further user-assisted rapid detection of structures such as sets of structures with the same orientation; and reduction of structures to "representative picks" which sparsely represent the structure orientations of a section of a borehole. In addition, integration of the workspace into WellCAD provides familiarity with the user interface and visualisation tools, and compatibility with existing file formats and workflows.
WellCAD 5.1 and the ISI workspace are now available. For more details please visit alt.lu
Main contributors in this research include: Eun-Jung Holden, Daniel Wedge, Mike Dentith and Nick Spadaccini. WellCAD image and stucture interpretation module Processing formation micro imager data Processing optical televiewer data