Geology 290M- 3D seismic Interpretation
Illustrated 3D Interpretation Workshop
Seismic Micro-Technologys 2d/3dPAK
Seismic Micro-Technology's Kingdom software is accessed
through the Windows Start Programs Menu.
In your program list select Kingdom Suite and then
left-click on Kingdom.
NOTE: Left clicking the mouse is used to start, continue
and end an activity. Right clicking is ONLY used for displaying
various pop-up menus.
Project files are opened from the initial Kingdom Suite window
(Figure 1). Click on Project then Open Project in
the drop-down menus.
| Figure 1: The initial Kingdom Suite
display window provides access to new and old project
This exercise uses the Golden 3D data set available on your
installation diskette. In this exercise, the C38 formation top is
selected from any well and then tied around to the remaining
wells. The entire 3D grid is interpreted. It is recommended that
major faults be interpreted at the outset, since this will
prevent autopicking of select reflection events across fault
When you open a project under Kingdom, the basic windows
layout will contain a 3D basemap (right) and project tree (left)
(Figure 2a and b).
2a: Basic window layout showing project.
| Figure 2b: Basic window
layout with 3D grid basemap.
- Left click on the 3D grid (Figure 2) to activate
it. Line and crossline numbers are plotted along
the sides of the basemap. In this example, position the
mouse arrow on Line 110. Right click and select Display
Line 110. The seismic line will now appear as
shown below in Figure 3.
| Figure 3: Display of 3D line 110 with
- If you prefer another colorbar,
left click on View and Colors. Click on File
and Open and select a different colorbar. In
most cases, the name of the colorbar describes the colors
and the number of colors in the colorbar. For example,
the default colorbar, brwbl50.clm, is a blue-white-brown
colorbar with 50 colors. Close the color editor once you
are satisfied with a colorbar.
- If you are accustomed to wiggle traces,
left click on View and Type of Plot
and select Wiggle Variable Area. You may need to
change the display scale to obtain the desired view. The
variable area wiggle trace display will appear as shown
below (Figure 4). Note the other display formats for
| Figure 4: Variable area wiggle trace
display format of Line 110.
- To change the display scales,
left click on View and Set Display Scales
or click on the scale bar at the top of the seismic line
display window. Try 8 traces per inch and 10 inches per
second to provide a close-up (Figure 5) view of waveform
character in the vicinity of the well shown above (Figure
4). Use the scroll bars to position yourself within the
| Figure 5: Close-up view obtained using
8 traces/ inch and 10 inches/second.
- You can orient yourself to
geographical directions by moving the cursor on the
seismic window (Figures 4 or 5) and watch the cursor
movement on the map. If the direction is backwards hit
the R key on the keyboard to reverse the line direction.
- The colorbar may or may not be displayed on the
seismic window. To display colorbar, left
click on View and Toolbars and then Color
Bar. A check indicates "on".
- Display features can also be accessed directly
using the buttons (Figure 6) in the upper left corner of
the trace window.
|Figure 6: Shortcut buttons on the line
display window. Buttons, left to right, select seismic
line, wiggle overlay, vertical seismic display scale,
color bar editor, a
toggle switch to display the color bar, and two zoom
control buttons. The drop down window at right allows the
user to select from time or data type.
- On the seismic line, several faults are
prominently displayed. Many of these faults are easy to
correlate others are not. Now would be a good time to
assign a name to at least
two of the major faults, the down to the south and the
antithetic. The others may be picked as assigned or
unassigned. To assign the faults, right click on
the seismic window and select Fault Management.
From there, select the Create tab and enter a name
and color for the antithetic fault. Left click on Apply.
Enter a name and color for the major fault and then
either OK or Apply. Create new faults if
desired, You're now in the fault picking mode with the
last created fault active.
- Display the fault toolbar to
allow for quicker selection of the faults you wish to
pick. To do this left click on View and
Toolbars and then Faults. All the displayed
faults are present, including Unassigned. Hot keys are
available: "D" enters the user into the fault
digitization mode, "A" assigns a fault, and
- To start picking your fault,
left click on one of the fault names. To begin digitizing
hit the D-key and then left click on the fault break that
courses through the seismic data. A rubber band should
appear as you go from point to point (Figure 7). Continue
left clicking points along the fault until you either
need to scroll vertically or horizontally to view fault
extensions outside your current view (Figure 7). Use the
scroll bar to move the display so that more of the fault
is visible. Continue until you can no longer pick this
fault. Double click to end.
If you enter a point you dont like, you can
back up or delete the last point by hitting the Esc
| Figure 7: Individual points digitized
along the fault appear as black squares connected by a
thin black line (or rubber band). To follow the fault
downward through the data, drag the rubber band over to
the scroll bar and slide down as you normally would.
- Left click on the other fault displayed in the
Faults digitizing menu to activate it and then hit
the "D" key to begin digitization. Begin
picking the second fault. If you choose to pick some of
the other faults on the Faults Toolbar, simply
activate the appropriate named or unassigned fault, hit
the "D" key and start picking. The two faults
you just picked should appear as shown in the montage
below (Figure 8). The number of points used to digitize
the fault will vary from interpreter to interpreter.
8: Faults just digitized on the northern end of the
line appear as shown above on Seismic Line 110.
- If you want to edit some of your picks,
the fault is active so long as the square dots are
present. Note that the red fault in the above display is
currently active. When a fault is selected for further
editing, little handles appear on each digitized point.
To move points, activate the fault and then left
click and hold on the digitized fault point. As you move
the mouse, the digitized point will also move. If you
move a small distance, you may have to use the Esc key to
undo the rubber band.
- If you would like to move the entire
fault line, first activate the fault and then
hold the Ctrl key and then left click and hold on any
part of the fault line. Move the line to wherever you
like and then release the mouse button and Ctrl key.
- To delete a fault segment, make
it active and then hit the delete key on your keyboard.
- To add points, left click on an
existing point, add the appropriate intervening points,
and double click on another existing point.
- To remove consecutive points,
left click on an existing point, skip the 'bad' points
and double click on an existing point.
- If you'd like to change the
active fault, left click on the new fault to
activate it or select from the Faults Menu. If the new
fault has no existing digital points, you must hit
"D" on either the keyboard or Faults Menu.
- To assign an unnamed fault,
activate the fault name, activate the unassigned fault
line and then hit the A-key.
- To de-assign a named fault,
activate the fault line and then hit the S-key.
- Once the faults have been picked on this line,
you can begin picking the faults on a grid of lines
extending through the entire 3D data base. To set
the grid spacing, left click on Line and Set
Line Skip Increment. Set the increment to 20
and then OK. Now whenever the right arrow on the
keyboard is hit, the line displayed will increase by 20.
If the left arrow is hit, the display will decrease by
20. If a cross line is displayed, the up and down arrow
keys will work likewise.
- Go to line 130 and digitize the main
down-to-the-south fault and antithetic fault.
- Once an assigned fault has been picked on at
least two lines, a fault surface is automatically
created. To view fault surfaces in map view
go to the Project Tree and double click on the
appropriate fault icon (Figure 9). This opens a new map
window where the fault may be displayed as either a fault
surface or segments.
| Figure 9: To display a fault surface
double click the desired name listed in your project
Map view of fault surface is shown below (Figure 10).
|Figure 10: The large down-to-the-south fault
is displayed in map view. Color-coded two-way travel
times appear in the color bar at right.
To toggle from planes to segments, go to View,
Fault Display Mode and select either Fault Surface or
The fault segment display is shown below in Figure 11.
| Figure 11: Fault segment display of the
main down-to-the-south fault.
- Display features can also be accessed directly
using the buttons (Figure 12) in the upper left corner of
the map window (Figure 11).
|Figure 12: Shortcut buttons available on the
map display window. Buttons, left to right, allows the
user to Select
fault surface to display, Select
Contour Overlay, Set Contour Parameters, Set Scales, Edit
Colorbar, Show Colorbar, magnification control buttons,
and a selection window that allows you to switch back and
forth from Fault Surface
and Fault Window
- Display the fault surface in seismic
view so that any miscorrelation can be quickly
seen. To do this, go to a seismic window and right click,
go to Fault Management, and Display. Verify
that Both is selected for Display Type (Figure
13). If "Both" is selected, two lines
are visible in seismic view, the straight line connecting
the digitized points and the interpolated fault surface.
|Figure 13: Fault Management window. Select Both
to display both the individual fault-trace picks and the
interpolated line fit to these points (see step 24
- Complete fault picking: Continue
over to the east-end of the survey to Line 145. Note the
dashed line representing the extrapolated fault surface
(Figure 14). This projection is displayed as a guide only
and does not represent the actual fault surface. When
complete return to line 90 and continue to the west. To
go to line 90, left click on Line
and then Select or left click
on the arrow button in the seismic display window
which brings up the same window. Type in 90 and be sure
the line button is on and that the 3D survey is
displayed. Hit OK. If you would like to view the
faults in strike direction or on an arbitrary line, right
click on the desired cross line in the base map
window and then display line.
| Figure 14: Extrapolated fault surface
shown as dashed line on the easternmost Line 145.
- To display line with an arbitrary
orientation through the survey, right click on a map
window, select Digitize Arbitrary Line,
left click on the starting point, continue left clicking
on each bend in the line (Figure 15) and then double
click to end. The digitized line will appear (Figure 16).
| Figure 15: An arbitrary line overlay is
extracted from the 3D survey using the digitize
arbitrary line option.
| Figure 16: Arbitrary 2D line digitized
in Figure 15.
At this point, your fault surfaces will be correlated
across the entire survey area. The north-dipping (antithetic)
fault surface, for example, will appear as shown below
|Figure 17: Color raster display of
north-dipping (antithetic) fault surface.
- Continue picking faults, in the western
direction. You can edit interpolated fault picks
by first selecting the desired fault as the active fault
in the Fault Management Window, and then hitting
the D key to digitize. If you wish to correct a portion
of the interpolated picks simply begin picking points
through the desired region. Double click to complete
digitization. Your picks will replace the interpolated
Note: If a fault has been extended too
far, you can delete a portion of the interpolated fault
line by digitizing the extended portion, and double
clicking to replace the interpolated line with your
picks. Then click on the bad pick and drag the rubber
band to the first good pick and double click. All points
beyond the last pick will be deleted.
- Once you are satisfied with your fault
interpretation you can begin picking horizons.
- As mentioned earlier, the seismic data will be
tied to a well using the C38 formation top. Display
line 80. Scroll until the well is visible and
the C38 top is displayed around 1.3 seconds. If the C38
top is not displayed, left click on Wells
and Wellbore Display Options,
Left click on Plot Formation Tops and OK.
The C38 should be displayed and correlated along a peak
| Figure 18: Horizon C38 tied to two
wells on Line 80.
- Horizons are created in much the same
way as faults. Anywhere on the seismic line, right click
and select Horizon Management. Select the Create
tab and then enter C38 for the
horizon name and then select a color. Hit OK. The C38
horizon is now active.
- Display the horizon in map view by
double clicking on the icon next to the C38 Horizon.
Since no picks have been made, no horizon is visible.
- Horizon Picking: Right click on a
seismic line and select Picking Parameters.
Make sure that Stop at Displayed Fault Surface
Intersections is enabled. This feature, when
enabled, works with the Autopick-2D Hunt mode. Picking
will stop either whenever data goes away or the horizon
encounters a fault surface.
- Display the Horizon Toolbar by left clicking
on View, Toolbars, and Horizon bar. Note that the active
horizon is highlighted in the toolbar. Hot keys are
available, M = manual picking. F = Fill made, H = 2d
Hunt. E = Erase. P = Peak, and T = Trough. Hot keys are
not available for zero crossings.
- Note the shape of the cursor and the status
bar. The cursor is now represented by a '+' with an E, M,
F, or H next to it. Change the picking mode to either F
or H, and change the phase to peak. Pick the event as far
as you can. Jump the fault if desired. Note that the map
display is updated immediately after picking.
- Once the horizon has been picked across the
inlines do the crosslines. Place the cursor on any cross
line within any inline seismic display, then right click
and display the crossline at that point. A small tick
mark is visible where the two lines intersect. The tick
mark color will be the same as that of the horizon you
are picking. You may also see a vertical red line. This
red line is a line overlay and can be disabled by left
clicking on View and selecting Line
Overlays. A check mark indicates 'on'. If you
chose the 2D Hunt mode, left click once on the
tick mark and the entire horizon between fault
segments is completed.
Increment through your data using the arrow keys and
continue picking this horizon, Remember that the skip
increment that occurs with each touch of the arrow key can be
adjusted using the Line, Seismic Line Skip Increment
selections. Then set the increment to the number of lines
desired (5 for example). Now is also a good time to check for
the consistency of your picks as you make your way through
the crosslines. You should end up with picked grid of lines
for the C38 horizon (Figure 19).
|Figure 19: Horizon picks are shown on the
grid of inlines and crosslines. Travel times are color
coded. Fault intersections (Main in Red and Antithetic in
Green) are correlated through the area.
- Draw fault polygons around the fault gaps
by right clicking on the map and then Enable
Fault Polygon Editing. Then select Digitize
Fault Polygons. You may find it useful to zoom in
on the faults to observe the gaps as shown in Figure 20.
Begin left clicking a series of points, which define the
fault gaps. Double click on the final point. The fault
polygon is drawn to outline the gap (Figure 20),
| Figure 20: Fault gaps in horizon C38
appear in a close-up view of the basemap.
It may help to zoom in and draw polygons around visible
segments in a close-up view. Use the slide bars to reposition
your viewing area farther along the fault. Continue
digitizing the polygon. When the rubber band is returned to
the adjoining point on the opposing side of the fault, double
click on that point. One continuous polygon will appear. Your
fault polygons will look similar to those shown in Figure 21
| Figure 21: Close-up view of fault
polygons drawn around the fault gaps.
Alternatively, use Auto Create Fault Polygons. This
option is useful whenever the fault surface is easily picked
and smooth. Go to the menu bar and select Faults, Auto
Create Fault Polygons. You can display fault polygons in
several ways: outline only, solid fill or solid fill with an
outline. To change the display, right click on the map,
select Fault Management then select the Fault
Polygons tab. Make your selection and hit OK.
- With this grid, the horizon is now ready
for the autopicker.
- Left click on Horizons on the Command
line and select Polygon Hunt. Using the left mouse
button, draw a polygon around one of the fault blocks.
Double click to end. Autopicking begins immediately after
double clicking. Continue this process using a series of
polygons. Not recommended is one giant polygon. Instead,
create a series of smaller polygons.
Note that you can bring up a seismic
line and go to regions of the data where the Polygon
Hunt operations are having trouble. You can manually
interpret the data in these regions directly on the
seismic lines. When you do this, the active seismic line
will show up as a red line. If you want to bring up a
line nearby you need only left click on the red line
overlay and drag it to the location where you need an
Your completed horizon interpretation will look something
like the one shown below (Figure 22).
| Figure 22: Two-way travel time map to
top of the C38 reflector generated from interpretation
and automatic computer tracking between picks.
- If you don't like how 3D Hunt worked in
particular area, left click on Horizons and select
Polygon 3D Erase. Draw a polygon around the
area of interest similar to 3D Hunt. You will he given
the option to erase hunted picks, seed picks
or both hunted and seed picks. Select hunted picks
only. Hit Yes and the polygonal area is wiped clean with
only the seed picks remaining. Repick a tighter grid if
necessary and rerun 3D Hunt.
- Once the map is completed, display the
amplitudes. Go to the Project Tree and left
click on the '+' sign next to the C38 horizon line.
This opens the horizon showing you the additional
surfaces available (Figure 23). Drag the amplitudes
from the Project Tree to the map window.
| Figure 23: View of Project Tree window,
Clicking the + sign at left on an individual horizon
opens a drop down list of other data available for that
horizon. In this case displays of amplitude and time are
Dragging the amplitudes from the Project Tree list to the
base map will cause reflection event amplitude to be
Horizon travel times are shown in Figure 22. Horizon
amplitudes are shown below (Figure 24).
|Figure 24: Horizon amplitudes for C38 Seed.
- Generate a time-structure contour map
by selecting Map and Select Contour
Overlay. Select the horizon and data type
(Time) (Figure 25). Click on OK.
|Figure 25: Contour overlay horizon selection
menu. Note the Parameters button.
After you click OK, the Contour Parameters will
automatically appear. You can also change the contour
parameters by clicking on the Set Contour Parameters
Icon to see what the effect is. You can check the effect of
various parameter selections by leaving the contour
parameters window active and selecting Apply.
Your result may appear similar to that shown below (Figure
| Figure 26: Contour Overlay on C38.
- Creation of a depth map is a two-stage effort
that begins with construction of an average velocity map.
To create a velocity map, select Tools
from the main Menu Bar and then Depth
from the drop down list. Under Depth there
are several selections. Click on Compute
Average Velocity Map. For Type,
select Horizon. The program computes
the average velocity at each well using one of
three options (Apparent, Time Grid or Formation Top) (Figure
|Figure 27: Method used to compute the Average
Velocity Map of a selected horizon
is selected in this menu.
The Apparent method used to construct the average
velocity map uses the horizon time and formation top depth.
You must provide a velocity map name (Figure 27). Gridding
parameters can be tailored to individual needs (Figure 28).
Time and depth pairs are then combined to form an average
|Figure 28: Gridding parameters selections
Average velocity in this (Apparent) approach is
computed by dividing formation top depth by half the horizon
time. Whether you Extrapolate (Figures 27 and 29) or
not (Figure 30) will yield two different results.
Extrapolation will project the resulting velocity grid
outside the area of well control.
| Figure 29: Velocity map formed by
|Figure 30: Velocity grid of C38 horizon
without extrapolation. Velocities were derived using the Apparent
The Time Grid method of deriving the velocity map
uses the horizon time picks, converts them to depth using the
well time/depth function and then generates a velocity grid.
This velocity map (Figure 31) is considerably different from
that obtained using the apparent method.
| Figure 31: Velocity grid from Time
Gridding (no extrapolation).
| Figure 32: Velocity grid from time
gridding with extrapolation.
Comparison of Figures 29 and 32 reveal notable but minor
differences in this example.
The Formation Top method of deriving a velocity map
starts with the formation top depth, converts it to time
using the well time/depth function and then generates a
velocity grid. If the horizon and formation top do not tie,
three different velocities can be generated. Use the default
grid parameters as a first pass for each velocity map. Depths
obtained from this approach (Figure 33 and 34) reveal subtle
|Figure 33: Velocity grid
obtained from Formation Top
method with extrapolation to the borders of the survey.
|Figure 34: Formation
Top conversion without extrapolation
yields this velocity grid, which has been extended to
incorporate well #10 along one of the 2D lines external
to the 3D survey.
- Once the velocity map has been generated, you
are ready to convert times to depth. From the top menu
bar click on Tools then Depth, then Depth
Map by Average Velocity Map. This will open up the
menu shown below (Figure 35).
|Figure 35: Depth
Map by Average Velocity Map menu.
Supply the appropriate information in the above menu
(Figure 35) and then click OK. The Grid Parameters
window (not shown) will then appear. Parameters can be
tailored to your specific project. Click OK to
generate the Depth Map (Figure 36).
|Figure 36: Depth map derived
from the average velocity map.
Edge effects may be noticeable on your depth map. These
areas can easily be removed using the Grids, Polygon Erase
utility. Polygon erase will provide you with a
"rubber band" that you can use to define an
enclosed region to delete. The operation is identical to that
used to digitize fault polygons. Digitize the points around
the region you wish to delete and double click to complete
- Contour the depth map and display the
amplitudes under the contours. Remember that you can
contour your maps using the Map Select Contour Overlay
options. Contours of velocity for the C38 horizon are
shown below (Figure 37).
|Figure 37: Depths obtained from
time-gridding (Figure 32) have been contoured for the C38
Amplitudes of the C38 reflection event can then be
followed along the structure by dragging the amplitude
horizon from the project menu onto the map (see
montage Figure 38). Note the association of amplitude
anomalies with the faults in this example.
| Figure 38: Reflection
event amplitudes combined with a depth contour overlay
for the C38 Horizon.