Author: Mike Cline, T/X Resources
Synthetic seismograms are a very important part of seismic interpretation (in my opinion, but that’s a future post), but sonic logs are often not available. This is where our trusty friend, the pseudo-sonic log, comes in handy.
Since I use synthetics on every one of my interpretation projects, pseudo-sonic log generation has been a long-time interest of mine. I even published an article in the Oil & Gas Journal (Cline, 1989), comparing sonic and density logs to pseudo-sonic and pseudo-density logs computed from Deep Induction Resistivity logs, using the Faust equation.
Since then, I have developed a technique to generate pseudo-sonic logs from Neutron Porosity logs, that shows promise as an alternative method. I have also included three other common techniques for comparison, in this posting.
See the larger Adobe Reader pdf file (six pages).
Author: Mike Cline, T/X Resources
How cool is this? I just found a new online spreadsheet application that allows you to share, collaborate, and publish spreadsheets that actually work when they are posted on a website, or blog. EditGrid received a very good rating from PC Magazine. The concept is somewhat similar to what is already being done with the online spreadsheet applications of Google Docs, and Zoho. However, the company focuses all of its efforts on the spreadsheet application solely, and apparently does a much better job at it, than either of its competitors.
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
The following is an example of an easy method to import culture lines into an SMT project, using a spreadsheet formatted as an SMT culture line file. Note that this is also applicable for importing polygons.
Suppose you have an SMT project that includes both 2D and 3D seismic data, but you only want to show the 2D line location overlays without the 3D line overlays, to reduce map clutter. Normally, SMT’s 2d/3dPak module only has the option to have all seismic line locations turned on, or to have them all turned off.
In the examples below, the first image, annotated “WITH ALL SURVEY LINES” is how a map would look with the Display Survey Line Option selected (Surveys>Survey Annotation> Line Options>Display Survey Lines). Often, this creates a lot of map clutter (in my opinion), especially if you have many 2D lines, or they are concentrated in one area. This map clutter can distract from the structure map, or other focus of the display.
See the larger Adobe Reader pdf file.
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
Being in business for myself, I have to wear several “hats” during the day. Not only am I a Geophysicist, but also must be adept at geology, marketing/sales, finance, etc. (and now running a blog). Whew, sometimes there doesn’t seem to be enough time in the day!
Another one of my duties, which often seems to take a lot of my time, is being the unofficial, computer support person for several computers: three of my own, one in a currently active client’s office, and three for my family—all with Windows XP (I’ve had no desire to jump to Windows Vista yet, with all of its reported problems, and slowness). It seems that I’m continually fixing something that is broken, corrupted, won’t work, etc., or continually searching for upgrades/fixes, and boy do I get frustrated with the seemingly never-ending problems.
As a result, I have recently started to investigate the possibility of using Linux as an OS (operating system). Let me state here, that I’m not an expert yet, by any means—I’m still way down on the learning curve. There’s still a lot to learn, but I thought that I would share some of what I have found out so far. Here’s a recent Linux user survey that I found, about some of the leading Linux distributions (distro’s in geek speak).
Author: Mike Cline, T/X Resources
This is a continuation of my previous Linux article (which eventually got too long for one posting), discussing the results from my Linux tests.
First, the negatives from my tests: From the initial results, additional research, and my other experiences, many of the currently available Linux operating systems (OS) doesn’t yet seem to be able to recognize every hardware component available like Windows usually does. Generally, Linux still has problems with network-related hardware (especially wireless adapters), video adapters, and some external devices such as printers, and digital cameras. Because of these network, and video-related problems, laptops seem to have more problems than desktops do.
Fixing a problem usually requires delving into the very “geeky”, and unfamiliar domain of the CLI (Command Line Interface, similar to the old MS DOS commands). It can be a bit intimidating, initially. Also, the general user-interface appearance on many distros are still very garish—I have no idea where they come up with some of the colors, or graphics symbols which are used, or when they did think of them, why they decided to use actually them. However, as they become a more mainstream OS, they will improve these problems. Actually, I can already see it happening, in just the short time that I’ve been looking into Linux.
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
Have you ever wanted to post a shortened version of the wellbore API numbers on a map because the original 12-digit UWI numbers created too much map “clutter”, but you didn’t have an easy way to do it?
Here’s an example T/X Resources spreadsheet that I use to create an SMT Culture file for posting the shortened, five digit API numbers above well symbols. (Note: just click on these links, and then select Save after the File Download box opens). In the image below, the 5-digit API number is posted above the well symbol (or surface location, if it’s a deviated wellbore), the well number to the right of the wellbore, and the TD below the well symbol.
See the larger Adobe Reader pdf file.
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
Did you know that you can improve the resolution of most seismic data with a data processing sequence known as Spectral Whitening (aka. Spectral Balancing)? What is Spectral Whitening? It’s nothing more than increasing the bandwidth, or frequency content, of a seismic data set. The increase of the higher frequencies (naturally filtered by the earth) allow the interpreter to resolve smaller features than would normally be observed.
See the larger Adobe Reader pdf file (four pages).
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
From time to time, we all have had a need for programs to view/manipulate geoscience data. Over several years I have collected a few website links that may be useful.
Here are a few links to free segy viewers that I’m aware of. Some of these are just basic segy viewing programs, but some also have editting capabilities:
1) Kogeo– Seismic data viewing, import/export, editing, navigation tools, and 3D visualization.
2) GSEGYView– Seismic data viewing, and some processing.
3) SeiSee– Seismic data viewing, import/export, editing, and plotting.
4) SeisVu– Seismic data viewing, import/export, editing, and plotting.