Print this pageEnhanced Carbonate Reservoir Model for an Old Reservoir
Utilizing New Techniques: The Schaben 
Field
(Mississippian), Ness County, Kansas
Timothy R. Carr, Willard J. Guy, Evan K. Franseen, and
Saibal Bhattacharya
The Pennsylvanian-Mississippian unconformity is a major stratigraphic event
in Kansas that truncates rocks ranging from Precambrian to Mississippian. Many
of the 6,000 fields in Kansas are located immediately beneath this unconformity.
One example, Schaben Field located in Ness Count , Kansas, has produced
approximately 9 million barrels since it was discovered in 1963. Production is
from the Mississippian (Osagian) cherty dolomites beneath the unconformity. The
field was initially developed on a regular forty-acre spacing, but recent
drilling has demonstrated the potential for additional targeted infill drilling.
To develop an enhanced reservoir model for the Schaben field modern core, log,
and well data were integrated with the existing data. New techniques such as "Pseudoseismic"
and the "Super" Pickett plot were used to leverage the existing data and provide
tools for analysis and 3D visualization. The pseudoseismic approach uses
well-logs within a standard 3D seismic visualization system to provide a
detailed macroscale view of karst patterns. The petrophysical analyses using the
"Super" Pickett plot were used to recognize subtle trends and patterns for each
of multiple reservoir intervals. Visual and petrographic examination of core
from the field confirms karst development and indicates multiple stages of
fracturing, brecciation, and dissolution features that were important in
controllin and modifying development of reservoirs. The resulting multiple stage
karst reservoir model for the Schaben Field emphasizes the opportunities
provided by both vertical and lateral reservoir compartments due to
well-developed karst. The understanding of the reservoir heterogeneities
resulting from the paleokarst model at Schaben field emphasizes the importance
of integrating available data
with new techniques to provide a predictive tool
for discovery of additional pay within existing subunconformity fields in Kansas.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California