Author: Mike Cline, T/X Resources
Do you ever need to use your SMT fault polygons for other applications? For example, I quite often convert them to an SMT culture layer, as a fault QC (quality control) tool, or use them in Surfer, when I need extended gridding capabilities.
The benefit of having an individual horizon’s fault polygons converted to an SMT culture layer is that you can easily keep the fault strikes consistent when working on an adjacent horizon, by overposting the culture layer onto your active horizon. I normally create fault planes on all of the faults that I see on multiple lines. However, some faults don’t extend far enough to be seen on more than one line, so it’s difficult to fault plane them with the lack of control points—a common occurrence in 2D projects, with widely-spaced lines (eg. regional projects).
Golden Software’s Surfer program has a wide array of gridding, and grid-manipulation capabilities, but it only uses the proprietary “bln” file format for faults. So, you will need to convert your SMT fault polygons to this format before you can use them in Surfer.
Author: Mike Cline, T/X Resources
Here are the results from another one of my Do-It-Yourself spreadsheet applications. This one creates a pseudo-shear log from a sonic log, using John Castagna’s “Mudrock Line” technique.
Often, shear sonic logs are difficult to acquire, so we may end up using a “default” shear log suggested by our AVO programs, which commonly use either a Poisson’s Ratio of 0.25, or a Vp/Vs ratio of about 2.0 to calculate the shear log.
However, there is a much better way, which Castagna illustrates in his classic 1985 paper (long title) “Relationships Between Compressional-Wave and Shear-Wave Velocities in Clastic Silicate Rocks”. In his article, he demonstrates that there is an excellent linear relationship between the compressional, and shear velocities of clastic silicate rocks, a technique which I have used many times, with successful end-results for many of my clients.
See the larger Adobe Reader pdf file.
Author: Mike Cline, T/X Resources
Anyone who has visited the Houston Geological Society’s (HGS) GeoJob Bank, or more specifically the GeoJob & Energy Statistics page, is bound to recognize this graph. During my nearly six-year tenure (2000-2005) as Chair of the Personnel Placement Committee, I created and updated the industry-related graphs on the Statistics page (amoung my many other duties). However, since I “retired” from the Committee in late 2005, the graphs haven’t been updated, so I thought that this would be a good venue to revive some of the graphs, and keep them current with updated information.
This first graph, in a series to come, is the oil and natural gas price curves for 35-years—from January 1973, through the last available data in December 2007. It was created from downloadable data from the U.S. Department of Energy’s (DOE) Energy Information Agency, and the Federal Reserve Bank of St. Louis, saved to a spreadsheet, and then graphed with Golden Software’s Grapher program.
See the larger Adobe Reader pdf file.
Author: Mike Cline, T/X Resources
After I finished the earlier posting, “Shaded Relief Maps for Subtle Fault Detection“, it occured to me that there may also be an interest in map displays for stratigraphic interpretation. This posting, and the one that immediately follows, illustrates how various map types and parameters can affect a stratigraphic interpretation presentation.
In the first slide in the series below, an autopicked two-way time color-filled map, a channel-like feature can be seen in the upper left quadrant of the mapping area. As we will see in later illustrations, it is fortunate that this colorbar was used—the channel may not have been as evident with other colorbars, as it is in this display. However, other than the two bounding faults (areas with the black crosses, indicating the manually-interpreted faults), not a lot of other structural and/or stratigraphic detail is evident. You can tell that the channel is draped across a nose, located between the red, high area to the northwest, and a gray area southeast.
See the larger Adobe Reader pdf file.
Author: Mike Cline, T/X Resources
Now for the less effective channel map displays:
Initially, I had included this portion in the original posting, “Effective (and Less Effective) Channel Maps” (see above). However, after thinking about it a while, I decided that it was too long, so I broke it up into two postings.
See the larger Adobe Reader pdf file.
As I mentioned in part one, the Channel TWT Color-Filled Map in the first slide of this series of images, is not as definitive because of the poor choice of colorbars. The upthrown fault block colored in red, increases the time range of the colors so much that the middle fault block, where the channel is located, is almost entirely in the green colors. This is the cause for the loss of color contrast, leading to less definitive channel edges. A map’s “dynamic range” (the spread of the largest-to-smallest values) is a key consideration when deciding on a colorbar.
Author: Mike Cline, T/X Resources
How fortuitous! I received my version 8.2 update of SMT’s Kingdom software this afternoon, and just got it installed. One of the new features that has been added to this version of 2d/3dPAK, is the ability to display the Shaded Relief of a grid. So, I thought that this would be a good time to introduce the technique to those viewers not familiar with the general concept. However, since I haven’t had a chance to get completely familiar with this newest feature in the SMT software, the surface and map displays shown below were created in my normal work flow using Golden Software’s Surfer program. As time permits, I’ll try to review, and compare, SMT’s new feature.
What is a Shaded Relief display? It is a map view of an artificially illuminated 3D surface whereby shadows are cast by minor deflections in the surface (shadowed deflections are facing away from the illumination source). This type of map is an excellent way to highlight smaller faults which may not have been seen, or noticed, on the vertical seismic displays.
See the larger Adobe Reader pdf file.
Author: Mike Cline, T/X Resources
Usually, color-filled maps are utilized for structure map presentations. Preference, or habit? If this applies to you, why not consider using a 3D shaded surface display, which transfers so much more information than a standard color-filled map, to display an interpreted horizon or gridded surface?
The animated display below compares an “overhead view” of a color-filled map, with a perspective view of a 3D shaded surface display. The black crosses on the color-filled map indicate where seismic faults were manually interpreted (at 500′ increments—or, every fifth inline and crossline in the 3D seismic survey).
See the larger Adobe Reader pdf file (two pages).
Author: Mike Cline, T/X Resources
Have you ever wished that there was a good, and easy-to-use program to capture just a portion of a screen, or menu item, or video?
Well, now there is one, FOR FREE! TechSmith, the makers of SnagIt have just offered a fully licensed copy of version 7.2.5 of their program on their website. This version is a slightly older than their most recent release (version 8.2), but it works very well. Not only that, but shortly after you register for their free version, they will even offer you a reduced rate to upgrade to version 8.2 (50% savings from the regular price).
See the larger version (2MB Adobe Reader pdf file)
Author: Mike Cline, T/X Resources
I use Golden Software’s Surfer 8 to create client presentation montages. It is a very easy program to use, and has a complete set of annotation tools. Importing seismic and map image files is a simple process. SMT has the capability to export scaled maps and seismic displays in a Windows Enhanced Metafile Format (EMF), which can be directly imported (at the proper scale) into Surfer. With additional printer emulation software (I use PDFCreator), you can also “print” (save to files) in other formats such as tiff, jpg, bmp, or png–Surfer is able to import these also, but lack the scaling info.
See the large Montage (5MB Adobe Reader pdf file)