Savannah River Site Project
Term Project:
In this exercise you will need to identify key marker beds in 18 well logs from the
Savannah River site in South Carolina. There is a blind (does not reach the surface) highangle thrust fault, called the Pen Branch fault, that you need to find. Your project is to
make structure contour maps and cross sections that will identify the fault and to
determine if the fault was recently active. Luckily for you, there are 25 wells (CFD-1
through CFD-18 and PBF-1 through PBF-8), and seismic reflection data in the area.
Nine wells go to basement and sixteen go down 300 feet. Also, you will be given a “type
log” from the area to help you get started. The Federal Government wants to build a
tritium and deuterium separation plant and needs to know the potential seismic hazards.
Good luck and get started early on your project; the builder has a deadline.
Material/data given:
1) Well locations, names, and elevations
2) A type log with picks
3) Composite stratigraphic column
4) 5 copies of the well locations (for your structure contour maps)
5) Seismic reflection data
6) Shot-point map
Instructions:
1.) Pick the same 5 markers on ALL of the wells using the same picks shown on the
type log. (Some of the wells were not logged completely, hence if the picks are
not present you do not need to record the picks – this mainly pertains to the PBF
wells).
2.) Make 5 structure contour maps (you need to use a fault break).
3.) Make 2 cross sections at any orientation that you think are appropriate to show
the Pen Branch fault. Be sure to label well locations and other information on the
cross sections.
Questions:
1) Using pick 6 or 7, calculate the regional dip of Black Mingo Group? Hint: use your
structure contour map and cross sections.
2) What is the approximate throw of the Pen Branch fault on basement? Hint: use the
regional dip of the Black Mingo Group and your basement picks in CFD-1 and CFD-18.
3) When was the Pen Branch fault last active? Hint: use your cross sections.
Turn in:
1) Well data [pick elevations (5 pts.) and elevations below sea level (45 pts.)]
2) 5 structure contour maps (25 pts.)
3) 2 cross sections (10 pts.)
4) Answers to question 1-3 (15 pts.)
Notes/words of caution:
A. Start early – the project could be difficult to start.
B. All the logs are not scaled the same, so be sure to look for patterns, not values.
C. Start making picks in wells CFD-7 – CFD-18, then move to the other wells.
D. There are some facies changes occurring in CFD-1 – CFD-6
E. Make picks on easier marker beds and using primarily the gamma ray logs.
F. Remember to convert pick elevations to feet below sea level.