Author: Mike Cline, T/X Resources
For those of you that haven’t had a chance to try out the Coblending feature in version 8.2 of SMT’s VuPak module yet, I would suggest that you give it a look. If you’ve never used anything like it before, be aware that it could max out your wowie-meter! Excuse the enthusiasm, but I like cool (and useful) technology.
(Back in the real world now) What is Coblending? It is just as its name implies—it is the ability to blend two different volumes of seismic data together, and display them both at the same time. Besides being very cool, it could also really be helpful with seismic interpretations—especially in complexly faulted areas.
See the larger Adobe Reader pdf file.
See the VuPak animation
Note: The avi file is fairly large, so it will take some time before the animation starts.
Author: Mike Cline, T/X Resources
Do you have a new 3D seismic volume that you need to review quickly? Maybe you just need to scan it to get a feel for the structural trends, or for quickly finding new prospects to concentrate on.
Whatever the case, SMT’s VuPak Chair Cut Animation, a common method of seismic visualization, is a good approach to use for the evaluation. It allows for the simultaneous viewing of three different planes of seismic data, as seen in the image below—Inlines (vertical data surface facing forward), Crosslines (vertical data surface facing towards the left) and Time Slices (horizontal data surface, facing upwards).
The data set being displayed below is a Coherency volume, which is an excellent seismic attribute for highlighting subtle structural and stratigraphic changes in the data. In this case, we’re looking for the major fault trends. Seconds after opening the volume for viewing, we find that there are two significant faults surfaces (the dark purple, linear features being highlighted by the red arrows), which can be seen traversing through various faces of the cube of seismic data volume.
See the VuPak animation (25MB 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
While we’re on the subject of channels…………….
Here is a “quick-look” visualization technique, accomplished within SMT’s VuPak program, which can be used for prospect scanning of new 3D seismic volumes—either standard migrations, or other seismic attributes such as angle/range-limited AVO (amplitude-versus-offset) volumes.
This prospect scanning technique highlights interesting seismic amplitude details in much less time than when standard, vertical seismic displays are used for the interpretation, and it also lessens the chance that subtle anomalies will be overlooked. The example shown here, is another presentation of the channel in the previous two postings, and is accomplished by quickly discriminating larger amplitude events from the “background noise.
See the VuPak animation (29MB 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
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
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.