U.S. GEOLOGICAL SURVEY DIGITAL DATA SERIES  DDS-33

                        3-D Reservoir Characterization of the House Creek 
                         Oil Field, Powder River Basin, Wyoming, V1.00                            
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                                                  README FOR MOVIES   

Software needed to run the movies

QuickTime software of Apple Corporation is required to view the movies.  Also needed is 
movie player software, most of which is freeware or shareware. Try searching the WWW using 
“movie+software” .  The  current WWW site for information on Apple QuickTime freeware is 
http://quicktime.apple.com.  QuickTime and MoviePlayer software for Macintosh computers and 
PC/Windows computers can be downloaded from links at http:/www.apple.com, or can be copied 
using File Transfer Protocol (ftp) with the following command:  ftp ftp.support.apple.com  .  
Unfortunately, this anonymous-user ftp site has a small quota, even with an additional 
ftptoo.support.apple.com site.  Because of a limited number of seats, we don't recommend 
accessing the site during business hours.
 
Movies can be called up from the text, but access is much quicker directly from the movies 
folder.  Should you have trouble displaying images, try increasing available memory by 
closing all unnecessary windows and software programs.  Shrinking the size of the movies 
may also aid in their display.  We recommend playing with the menu bar located at the top 
of the movies and the bounding scroll bars; both to improve the image display and to 
familiarize yourself with program capabilities, including print and file export.

Explanation of movie images  

The six movies located in the " movies " folder display 3-D distribution and volumes of 
porosity and permeability for the Upper Cretaceous Sussex "B" sandstone across the 
southern two-thirds of the House Creek oil field, Powder River Basin, eastern Wyoming. 
Information on data sources, and technical and research methodology are located in the 
techinfo.htm file located in the "ssx_txt" directory.  A glossary is included (glossary.htm) 
in the "ssx_txt" sub-directory for definitions of computer and geologic terms.

Vertical exaggeration of the 3-D images ranges from 20 to 60 times.  The Sussex "B" 
sandstone is less than 60 ft (18 m) thick and would look like a razor's edge without the 
exaggeration.  The House Creek oil field is about 1 mi (1.6 km) wide and, combined with 
the small Porcupine field at the southern boundary is about 36 mi (58 km) long.  General 
reservoir-grade intervals in images are shown on the porosity (left) color bar by green 
through red (8 to 21 percent porosity); low-porosity non-reservoir intervals are purple and 
blue (1 to 8 percent porosity).  Movies show: 

     1)  The field boundary, thickness of "B" sandstone intervals, color codes for porosity, 
permeability, and oil production increments, and index contour maps with location of 
reservoir slices in the field, 

     2)  Upward and seaward (eastward) increase in depositional energy, porosity, 
permeability, and oil production for each of the four stacked sand ridges that comprise the 
field.  Stacking of high porosity and permeability intervals is also controlled by where each 
sand body is located relative to bounding sandstones.  Greatest reservoir properties are when 
highest-depositional-energy facies of both sand ridges are stacked, as opposed to landward 
backstepping of the overlying sand ridge.  An example of this is the sand ridge located below 
the E in figure 20.  The overlying sand ridge was deposited to the west.

       3)  Concentration parallel and proximal to field axes of the greatest oil production, and 
thickness and lateral continuity of reservoir-grade sandstones, 

       4)  Vertical and lateral change in porosity and permeability.  Porosity values are 
gridded at approximately 1 ft (0.3 m) vertical increments.  Well locations of core porosity 
data commonly exhibit diamond shapes.  The diamonds show reservoir heterogeneity 
through the great variation in values over short vertical and lateral distances.  Porosity 
calculated from well logs does not display as much variation because the data are smoothed 
over ranges of several feet.  Permeability movies also show this change at the well-bore 
level; all permeability data are core values. 

       5)  Reservoir compartmentalization resulting from laterally continuous permeability 
barriers between sand ridges.  Permeability barriers (blue and purple colors on the porosity 
models) are mainly the low-depositional-energy mudstone and calcite-cemented sandstone 
facies.  These are located toward the base of sand ridges, except where removed by 
erosion during and prior to deposition of overlying sand ridges. 
 
Individual GIF files used to generate the movies are stored in the below directories 
(bounded by parentheses); GIF files are displayed in the text portion of this publication as 
single images, and as slide shows using an external viewer, such as  JPEGView  and  
LView .  All movies are stored in the  movies  directory; 

         1)  ewpermvf.MOV : east-west vertical slices of permeability for the northern half of 
the field area.  0.70 MB     (3dvk directory) 

        2)   ewporosv.MOV  : east-west oriented vertical slices of porosity across the field.  
13.9 MB     (ewporosv directory)

        3)  hporosf.MOV : plan view of the field.  Shown are horizontal slices of porosity 
from the base of the "B" sandstone upward. 2.3 MB      (hslice directory)

        4)  hporperf.MOV : plan view of the northern half of the field area.  Shown are 
horizontal slices of permeability and porosity from the base of the "B" sandstone upward. 
3.2 MB      (hporper directory)

        5)  nsporvf.MOV : north-south oriented vertical slices of porosity across the field.  
1.5 MB      (3dgifns directory)

        6)  volporf.MOV : onion view  along the eastern (seaward) margin of the field.  
Layers of porosity are stripped off, primarily in 1 percent increments.  Cumulative volumes 
are displayed for each porosity increment of the Sussex "B" sandstone.  0.74 MB      
(esid_gif directory)