Reveal is a periodic newsletter that highlights some of the recent additions and changes to Reveal. In this edition we discuss the new wells format along with some new tools and updates that were added since the last Reveal newsletter in August.
The Reveal software is now an integrated part of Shearwater GeoServices.
Shearwater GeoServices will become an integrated provider of marine geophysical services and 21st Century Processing Software to oil and gas and multi-client companies worldwide. Starting out with a fleet of four modern, high capacity seismic vessels, Shearwater’s core strategy will be to provide high quality marine geophysical services and utilize the company’s position as the most cost-efficient company in the industry.
“Over a period of time, we have examined opportunities to establish a new geophysical company, based on the four high-end vessels we currently own. In Rasmussengruppen, we have found a partner who shares our view of the opportunities offered by the geophysical market at present, and, equally important, who shares our vision to build and develop Shearwater into a leading player in the industry”, said Irene Waage Basili, CEO of Shearwater.
GC Rieber Shipping and Rasmussengruppen will own the company 50/50 with Shearwater receiving technical and crewing support from GC Rieber Shipping with regards to marine operations. Shearwater’s own organization is being established, in part on former Dolphin Geophysical staff and in part on new hires, and will be capable of offering customers with fully integrated geophysical services and operations from the start.
DipExtract2DB is a new tool that simplifies adding dip-field values to a DB. The locations for the points can be on a regular grid or from an already existing DB-file, e.g., TomoPicker output.
The resulting DB can be rendered on top of seismic for a quick QC combining picks and dips as shown in Figure 1.
Figure 1: Dip DB rendered on top of seismic
FKxKyFilter applies a filter in the F-Kx-Ky domain allowing for specific targeting of linear noise. This is particularly useful for eliminating ground roll. Figure 2 shows a snapshot of a land shot record with ground roll (left) and after the FKxKy filter (right). Notice how well the ground roll has been suppressed. FKxKyFilter is available in the advanced land and advanced marine packages.
Figure 2: Shot record with ground roll (left), shot record after FKxKyFilter applied (right)
VelTie2D ties 2D velocities at their intersections. It does this by taking an intersection database file from LineTieCompute and velocity dtb files and ties them at their corresponding intersections. The velocities at the intersection are averaged and smoothed within a radial input parameter. Figure 3 shows two velocities at an intersection before tying and Figure 4 shows the same two after tying. VelTie2D is available in the base package.
Figure 3: Intersecting lines before tie
Figure 4: Intersecting lines after tie
Well Log Data in Reveal
The Reveal ModelBuilding package has been upgraded with new tools and workflows to make it easy to use well-logs in Reveal.
The improvements include:
.well file format for easy integration of well data into Reveal projects
a new tool for importing LAS files and other auxiliary downhole data such as check shots, deviation curves and formation tops;
rendering of wells and well curves on seismic data in the 2D and 3D viewers, both in time and depth;
well-log curve display and editing;
building models with log curves;
other tools that use or convert well-log curve data.
Importing LAS curves and auxiliary data – A new tool, LASImport, creates .well-files from LAS files. In addition, auxiliary data - checkshots, deviation curves and formation tops - can be added. LASImport automatically parses the LAS file and identifies curves, datums etc. while allowing the user to specify what curves to import. The user may also modify units and datums if needed. LASImport can be run in single-well mode or for batch import using Python substitution.
.well-files -- A new file format, called a .well-file, includes the log curves and all the auxiliary data. By double-clicking on the .well-file, a tabbed display is opened, with tabs for curve display, general well information, crossplotting, and auxiliary data tables. Figure 5 shows two of the tabs - the curves display and the crossplot display.
a) Curves Plot tab – curves may be reordered, overplotted, rescaled, zoomed, selected and deselected
b) Crossplot tab – DT vs NPHI colored by depth. Any two curves may be crossplotted for each of the three point sets
Figure 5. Displays available for double-click on well file
Rendering of wells on seismic data – Well files can be visualized on seismic data by dragging and dropping any number of well files on top of the display. In Figure 6, 25 wells have been dropped onto a stacked depth image. For time displays the well curves and formation tops can be converted to time in the viewer.
Figure 6. Wells displayed on seismic data
Once the wells are displayed, they can be configured all at once to display any curves. Figure 6 displays two curves, as well as formation top names. The display is fully customizable, with user dialog parameters for setting curve order, color, line thickness, etc. Curves can be gained, repeated or filled (especially useful for synthetic curves).
Well editing – A new tool, WellEdit, allows creation of new curves from and the repair of existing curves via a predefined set of actions (see Figure 7). The actions list is similar to a processing flow for well curves: curves created in previous actions are available for use in subsequent actions as shown in Figure 7: three actions have been added. First a synthetic trace has been created, followed by a smoothing of that synthetic trace. The actions need not depend on each other: the third action, table2curve, creates a new well curve from a velocity table. Actions may be reordered by dragging and dropping an action to its new location.
Figure 7. WellEdit GUI
When new curves are created, they are added to the curves list in the Curves Plot twisty (the display is similar to the one shown in Figure 5). The new and modified curves may be displayed, overlain on other curves, reordered, rescaled, zoomed, etc., as with any well log curve. The synthetic curve created in WellEdit can be output as a trace, either in time or depth, and carried along in processing flows as a powerful QC.
Building models with well curves – HorizonFill is the workhorse tool in the ModelBuilding package for creating horizon-delimited models. It has been upgraded to use .well-files. Figure 8 shows a model built conformably to horizons by interpolating between wells. The well curve is displayed at the well location. Such a model built from velocity log curves might be used as a starting model for migration in the sedimentary section, or as a quality control for the output of tomography. Here a raw log curve has been used to illustrate HorizonFill’s capabilities. However, any processed curve (e.g. v0-slope of a velocity curve between formation tops, or one created from a velocity table) may be used.
Figure 8. HorizonFill model building with well curves
Other tools that use or convert well log curves – Well2Trace and Trace2Well are two new tools that allow converting well curves to seismic data and bringing a seismic curve back into the well file. Using this pair of tools makes the full richness of the seismic processing tool set (e.g. filtering and transforms) available for processing well log curves. New tools, e.g. Python tools, may be written to process log curves in ways not available in existing tools or in WellEdit.
Workers can now be ‘drained’ to allow it to complete the current replica, then gracefully quit. By stopping worker jobs in this way, work done on the current replica is not lost.
The capability to sync loaded db files has been added. This behaves similarly to how syncing seismic and velocity files behaves.
CentOS 5 End of Life:
CentOS will reach its upstream end of life in March 2017. Around this time we will also terminate support as we move our build server to CentOS 6. This should be transparent to most users. Custom tools which depend on the older libraries may need to be upgraded.
Shearwater had a large presence at the 2016 SEG conference in Dallas, TX. Reveal Shearwater had a large presence at the 2016 SEG conference in Dallas, TX. Reveal was on full display at the Shearwater booth including live demos of the software.