Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Geoscience For Gis A


Published on

  • Be the first to comment

  • Be the first to like this

Geoscience For Gis A

  1. 1. Geoscience for GIS Andrew Zolnai 1
  2. 2. Let’s use what we already have at hand • ArcMap: • Many datasets at once is the sweet spot • Simple surface and thickness trends • Model builder to implement workflows • Extensions: • Spatial Analyst (raster integration) • 3D Analyst (simple surface analysis) • Interoperability (link other datasets) • Output (ArcReader, MapBook, Schematic etc.) • Web services • ArcIMS (old but stable and widespread) • Web services (on-line community) • ArcGIS and Image servers (new and improved) • Intent here • Provide rough sketches with existing tools @ hand • As first step to further integrate with other systems 2
  3. 3. ESRI tools vs. Other tools • Upcoming release with simple • Download a script from ESRI grid/contouring in 3D Analyst • ArcScripts page • Enhance current extension with • Download / buy shareware simple industry-standard code • such as ETgeowizard • Use the 3D-, Spatial- or Geostatistical-Analyst • Buy software that extracts, transforms and loads (ETL) • Note current restriction: single ZM per XY (topologic integrity constraint) • Safesoft FME Workbench • Create multi-patches • Use existing integrator tools such as: • not easy to implement but resources • ArcView extensions by CGG, Landmark do exist or Schlumberger • Use ArcMap Model Builder to • Direct data exchange tools such as integrate other desktop • OpenSpirit grid/contouring • ESRI Data Interoperability • note that this is less evident and extension needs some scripting skills (a subset of FME Workbench) • Use ArcGIS Server SDK to integrate • Let ArcMap read web services that post other server-side grid/contouring grid/contours • note that this is not evident and • Such as Petrosys needs programming skills 3
  4. 4. ESRI tools vs. Grid/contours • Evenly spaced points • Unevenly scattered points • 2.5D topography, culture • 3D Wells, reservoirs • Use GRID or TIN directly • 2D / 3D seismic surveys • Use Spatial Analyst • Use gridding algorithm • Interpolate surface from points • To interpolate even datasets • Contour interpolated surfaces • Size / direction to reflect geology • IDW (allow barriers) • Use contouring algorithm • Spline (smooth or tension) • Similar algorithms • Krigging (geologic model) • Model the geology • Display in 3D and Spatial Analyst • Display results • Draping • 3rd party application • Shading to show structures • Read web services • Thickness and trend relationships • Read server services • Use Model Builder • Import into GIS • Link together several processes • Use grid or raster • Use canvas to mimic workflows • Think of 3rd party as pre-process • Overlay other datasets • Think of GIS as post-process • Culture, permits, parks etc. • Link to any tool at left • Satellite imagery, and • GIS is not just for mapmaking • Real-time tracking data 4 • Maps only report from database
  5. 5. Simple Thickness Workflow • ArcMap • Have two horizons as raster files • Raster Calculator is in Spatial Analyst menu • Subtract the two surface to get a thickness • ArcScene • Drape the thickness on the lower surface • Contour from 3D Analyst | Surface Analysis (more complete contouring in next section) • Drape the contours on formation top (that which is seen on logs or seismic) • Extrude them down from the top • Quick area and Volume from thickness • Mimic porosity effect by using Z value • Show simple volumes in vector space • Multi-patches for wellbore representation DATA: from EarthSoft's EQuIS website 5
  6. 6. Contouring Workflow • Three options • IDW (Inverse Distance Weighted, similar to Natural Neighbours) • Non-interpretive computation on neighbouring points • Calculates from fixed raster surrounding sample • Honours faults as polyline barriers • Spline • Force a curved surface through the raster points • Regularised: smoothest shape (stratigraphic plays) • Tension: tune the stiffness (structural plays) • No barriers but tuning parameters • Kriging • Average from a cloud of surrounding points • Can be made very complex (Geostatistical Analyst) • Can be shaped to mimic geology • E.g.: structural trend s.a. fracturing 6
  7. 7. Display Options • Viewing the data • In ArcScene • Use transparency and priority to show various datasets • Use the illumination to view trends • In ArcMap • Use the paint tool to compare overlaps • Use the same tool to verify raster (surfaces) and vector data (faults) coincide 7
  8. 8. Interpretation • How is it interpreted? • If for example thickness increases with elevation (with or without a mirror image if the entire structure is preserved), that may be an indication of thickening via fracturation atop an anticline, and therefore of structural trap and play (below left) • If however thickness decreases with elevation (below right), that may be an indication of a pinch-out and therefore of a stratigraphic trap and play (usually these also occur alone, and do not have an adjacent mirror image). • The presence of conjugate faults (two fault trends that are at a low angle to each other, below left) is often aligned with a regional fold or bend, and may also indicate a structural play. 8
  9. 9. Conclusion • What more can be done? • More factors can be taken into consideration using more Spatial or 3D Analyst and other extensions • Model Builder can be used to • concatenate several repetitive calculations and operations • thus mimic entire workflows • briefly described in next section • Note • ArcMap tools are used out-of-the-box to show what can be with GIS tools as-is • neither scripting nor programming was used here • This will not replace gridding / contouring or reservoir analysis packages • GIS is meant to work in conjunction with those packages, as noted in the opening table 9
  10. 10. Thank you Course notes available 10
  11. 11. Model Builder Optional 11
  12. 12. Model Builder - 1 • A canvas allows to link together tools from ArcToolbox: • Based on input data and a process • Output data is next process’s input • Running the model steps through each process: 12
  13. 13. Model Builder - 2 • Resulting model: • Resulting surface: 13
  14. 14. Model Builder - 3 • What was done? • Inverted a formation top into a raster slope • Modelled surface water flow as an analogue to subsurface petroleum flow • Draped the result onto the original formation top • Thus approximated up-slope subsurface fluid flow • What was used? • Spatial Analyst extension to process rasters • 3D Analyst extension to display vectors • Model Builder tool canvas to tie it altogether • Only with available pop-up and drop-down tools • Caveats • This is a surface flow model adapted to subsurface flow • Flow will diverge not converge, and create many vertices • To be further refined with additional surface factors • Such as described in the contouring section above 14
  15. 15. Resources • Best Practices: GIS for Petroleum • ESRI 2007, online PDF • Visualizing integrated three-dimensional datasets (multipatches) • Ford, A • ArcUser (ESRI), January - March 2007 • Introduction to GIS for the Petroleum Industry • Gaddy, D.E. • PennWell, 2003 • Geographic Information Systems in Petroleum Exploration and Development • Coburn, T.C. and J.M. Yarus • AAPG, 2000 • Contouring Geologic Surfaces with the Computer • Jones, T.A., D.E. Hamilton, and C.R. Johnson • Van Nostrand Reinhold, 1986 15