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
This posting is another example of the power of shaded relief maps, and the details that they can provide.
The initial image below is a normal, color-filled elevation map of the world—the white color is the highest elevation (the Himalaya’s, of course), and the dark blue is the deepest depths of the oceans. The Digital Elevation Model (DEM) of the Earth was downloaded as a grid, and then loaded and displayed in Golden Software’s Surfer program.
Following the inital color image, is a series of gray-scale shaded relief maps. Starting with the second image, the illumination source is directly from the north, at a 45 degree angle above the horizon. In each successive image the illumination source is rotated counterclockwise 45 degrees. The light direc- tions therefore are from the: north, northwest, west, southwest, south, southeast, east, and finally, the northeast.
See the larger Adobe Reader pdf file.
Author: Mike Cline, T/X Resources
Why bother using synthetic seismograms (aka. synthetics) to calibrate well info to our seismic data? Simple answer, TO REDUCE DRILLING RISK !
For example, I’ve seen prospects “evaporate” because the originator was mapping the wrong event—or just as bad, started mapping on the correct event, but ended up on the wrong event due to a character, or response change in the seismic data. This only became evident after a couple of synthetic correlations!
I also continue to see prospects that are being sold on the strength of an amplitude, or avo response, that is somehow related to a key wellbore. However, often a synthetic hasn’t been used to tie (correlate) the well to the seismic data. How could they even know for sure what was causing the anomaly, without a synthetic tie?
So, with these recent real-life examples in mind, I thought that it would be a good idea to cite some reasons why we should use synthetics, with a blog posting.
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Author: Mike Cline, T/X Resources
One of the limitations of seismic visualization that I often encounter, prior to interpreting the data, is being able to effectively isolate a geobody without including too much of the surrounding data.
For those new to visualization, the two common methods for displaying geo- bodies are: (1) Amplitude Restriction within a window (requires no previous interpretation), and (2) Data Extraction adjacent to an interpreted feature (ie. a fault, or horizon). Method 1 is usually faster, but can leave in a lot of extraneous data, as I’ve already mentioned. Method 2 is usually better at eliminating extraneous data, but most of the time it can’t be done until after a detailed interpretation—not much help if you’re in a hurry to see something.
So, I’m mainly looking for a method that can be used prior to a detailed inter- pretation, but is much better than Method 1 (and hopefully quicker than Method 2). The idea that I had is similar to the erase function in many raster image editing programs. Why can’t we erase the seismic data that we don’t want, just like we erase pixels in an image, using a combination of polygons for larger areas, and an adjustable “eraser” tool, for detailed, manual deletions.
See the larger Adobe Reader pdf file (four pages).
Note: The avi file is fairly large, so it will take some time before the animation starts.
Author: Mike Cline, T/X Resources
Has this ever happend to you? Just as you are getting ready to plot a horizon/grid as a finished, color-filled map for an upcoming meeting (a short fuse of course), then you notice anomalous data ”spikes” and/or “black holes”, that really detract from the appearance (and credibility) of the map? Don’t feel too badly though, they aren’t always that obvious on most of these types of “flat” map displays—often seeming to appear out of nowhere.
To correct the map, you have to go through the tedious process of trying to find the bad data, fixing it, and then trying to recreate the display just as you had it earlier (with all of the same title block and scale info that you had before, but forgot to keep)? Arrgghhh……. There has got to be a better way!
See the VuPak animation (17MB Media Player avi file).
Note: The avi file is fairly large, so it will take some time before the animation starts.
Author: Mike Cline, T/X Resources
In this SMT VuPak 3D perspective display, only the largest 30% of the seismic troughs (negative amplitudes) have been selected. In conjunction with this amplitude extraction, the “Base of Channel” horizon, fault interpretation, along with the nearby wellbores have been selected for viewing. This results in an impressive cloud of large amplitudes, which exhibits a distinct, and channel-like sinuous character (red event, highlighted by yellow arrow), in close proximity with other controlling geologic features.
See the VuPak animation (18MB Media Player avi file), or see a larger Adobe Reader pdf file.
Note: The avi file is fairly large, so it will take some time before the animation starts.
Author: Mike Cline, T/X Resources
Since the first posting, I’ve gotten nothing but encouraging comments. Here are a few:
“Good work Mike.” (Michael M.)
“This is very interesting!” (David W.)
“Excellent idea.” (Teri B.)
“I think it’s a great idea.” (Sara V.)
“Works!” (Yvon H.)
“Wow! You did it.” (Mark C.)
“Thanks a lot for your blog, brilliant idea.” (Julien F.)
From the sound of it, visitors may be starting to realize the potential usefulness of the blog (at least I hope so), and how the old SMT User email forum might mesh with it. I also just checked my website stats, and the number of “hits” is up by orders of magnitude–so I know it has gotten some interest from viewers.
Author: Mike Cline, T/X Resources
As a standard practice, interpreting seismic faults is done on vertical seismic displays (VSD). However, this can be problematic, and very time consuming, in a complexly-faulted area. For a correct interpretation, the initial fault interpretation picks must be connected properly. An easier, quicker, and more accurate method than using VSD’s for this, is to interpret faults in the horizontal domain.
See the VuPak animation (29MB Media Player avi file), or see larger Adobe Reader pdf file.
Note: The avi file is fairly large, so it will take some time before the animation starts.