Using Computer Spatial Technologies
(Geoplus Petra) for Subsurface
Geological Analysis and Visualization
Dave Barnes
Geosciences, Western Michigan Un
Kalamazoo, MI
barnes@wmich.edu
Berea Project: Williams Oil Field;
Bay& Midland Co, MI
• The lab project is a culminating activity (following work
with conventional core and petrophysical logs) in which
the students compile a subsurface "project" using
computer spatial technology software, Geoplus Petra.
• The project emphasizes the utility of spatial data,
interpretation of petrophysical logs, and the application of
sedimentologic and stratigraphic concepts to the analysis of a
real oil field well data.
• The project results in a stratigraphic analysis and
visualizations of an oil producing, deltaic succession and
prediction of the subsurface geology in the field area.
Nature of the Exercise
• The lab activity is an extra credit exercise using
computer software for undergraduate
Sedimentology and Stratigraphy Class and also as
a more extensive projects for a Graduate Clastic
Depositional Systems class.
• The project requires an understanding of
– basic depositional systems concepts,
– Lithostratigraphy – physical continuity correlation
– introduction to petrophysical log analysis,
– computer literacy with quantitative geological data
software (spreadsheets and the like)
The Learning Outcomes include:
• Use of spatial and quantitative geological
data for subsurface geological analysis.
• Subsurface, sedimentary facies-oriented
stratigraphy;
• Basic petrophysical log analysis;
• Lithostratigraphic (continuity) correlation
and visualization;
Application of the Materials
• Will require acquiring the software
– Available as a demo from the software developer
(http://www.geoplus.com/html/download.html)
• You will have to ask for demo version (30 day use) that will
accept your own (rather than the developers) project data
– Available for a nominal fee ($500) for installation in a
network license server mode with 20 seats (such a
deal!)
Application of the Materials (cont)
• Will require considerable head scratching to
become proficient with the software
– If subsurface geology/computer spatial technology is
your bag this is definitely for you!
• Software developers are very helpful and
supportive
• I (and especially my students!) can help
barnes@wmich.edu
Brief Review of Procedures
• Using Petra, create a project
Brief Review of Procedures
• Import well data from berea_project.csv file or
Petra Project file (BEREA Project.PPF)
Brief Review of Procedures
• Import petrophysical well log data (LAS batch is
the easiest, ASCII *.txt file is the hardest, ASCII
CSV files are better but slower, no batch mode)
Brief Review of Procedures
• Use Petra’s Thematic Mapper module to import MI county,
township, section, and quarter-quarter section shape files
as overlays into the Berea project. The ability to use and
manipulate ESRI shape files (without ARGIS software) is
VERY COOL.
Brief Review of Procedures
• Create a map of the oil field using the mapping module.
Fiddle with the formatting of the land grid files in the
Overlays pull down menu, Preferences and Layers
Brief Review of Procedures
• In the wells pull down menu, chose highlight
wells, by data criteria and log data, identify
those wells with any curves at all.
Brief Review of Procedures
• Create well to well cross sections in the mapping module
from the Cross Section pull down or Cross Section Icon.
• Use the Logs pull down (or select logs and scales icon) to
set up log display. This will take some fiddling. Go through
each select logs and scales tab and set up the log display to
configure scales, style (including cutoffs), tracks (widths and
track label ht).
Brief Review of Procedures
• Create formation tops in the Correlation tool bar (make
sure that this tool bar is available through Tops pull down,
correlation tool bar) for top Beret SST, top Transgressive
sand, Base Transgressive Sand, Top “B” Sand, Base “B” Sand,
Top “A” Sand, Base “A” Sand. These are provided in the
data set
Brief Review of Procedures
You can create both structural and
stratigraphic cross sections.
Brief Review of Procedures
• Return to Mapping module and select wells for
gridding from Wells, Select Wells by Data, Select
Wells by Tops
Brief Review of Procedures
• Gridding is a complex business, we will just use defaults to
create a structure contour grid (“depth to” grid) from the
top Berea Sandstone Fm tops data; Contours pull down,
Create Grid. The defaults set you up to create the grid and
save the file.
Brief Review of Procedures
• Display the grid just created using Contours
pull down, Display Contours
Brief Review of Procedures
(“depth to” grid) from the top Berea
Sandstone Fm Note the plunging
anticline structure of the oil field
Brief Review of Procedures
• I have provided isopach data (on the basis of “tops picks”)
in the FmTops area of the Main Module. This should
normally be done by the investigator using the Correlation
Tool bar X-section Module.
Brief Review of Procedures
• Isopach data (“thickness” rather than “depth to”) is
available for the logged wells only. In Mapping Module you
must Select Wells, from the Wells pull down to select wells
by data criteria (as before) to analyze wells with relevant
data.
Brief Review of Procedures
• Create isopach Grids for the “B” and “A” Sands as above
using data from Zone Data,Well
Brief Review of Procedures
• Display Isopach Grid Contour maps
Outcomes
• The student compiles oil field well data, including
spatial locations and digital well logs, for analysis of
subsurface, oil reservoir lithostratigraphy and
lithology using computer spatial technologies
software, Geoplus Petra.
• The students create well log cross sections, make
lithologic picks, construct structure and isopach
maps, and evaluate lithologic properties, including
gross reservoir quality from petrophysical logs.
•
Outcomes
• These data are used to interpret depositional
environment of the subject formation and make
predictions for well bore perforations for oil
production.
• The key value of the exercise is an introduction to
the use of computer software to analyze geological
data, guided by sedimentologic and stratigraphic
insights, and make predictions for resource
exploitation.