AAPG Bulletin, V. 84, No. 8 (August 2000), P. 1069-1086.
Schaben Field, Kansas: Improving Performance in a Mississippian
Shallow-Shelf Carbonate (E&P Notes)
Scott L. Montgomery,1 Evan K. Franseen,2 Saibal Bhattacharya,2
Paul
Gerlach,2 Alan Byrnes,2 Willard "Bill"Guy,2
and Timothy R. Carr2
©Copyright 2000. The American Association of Petroleum Geologists. All rights
reserved.
1Petroleum Consultant, 1511 18th Avenue East, Seattle, Washington 98112;
e-mail: [email protected]
2Kansas Geological Survey, 1930 Constant Ave., Lawrence, Kansas 66047-3726.
Special thanks to the U.S. Department of Energy, National Petroleum Technology Office,
Tulsa, Oklahoma; the Kansas Geological Survey; and Ritchie Exploration, Inc., Wichita,
Kansas, the organizations responsible for this reservoir characterization study.
ABSTRACT
Schaben field (Kansas), located along the northeastern shelf of the Hugoton
embayment, produces from Mississippian carbonates in erosional highs immediately beneath a
regional unconformity. Production comes from depths of around 4400 ft (1342 m) in
partially dolomitized shelf deposits. A detailed reservoir characterization/simulation
study, recently performed as part of a Department of Energy Reservoir Class Oil Field
Demonstration Project, has led to important revision in explanations for observed patterns
of production. Cores recovered from three new data wells identify three main facies:
spicule-rich wackestone-packstone, echinoderm wackestone/packstone/grainstone, and
dolomitic mudstone-wackestone. Reservoir quality is highest in spicule-rich
wackestone/packstones but is subject to a very high degree of vertical heterogeneity due
to facies interbedding, silicification, and variable natural fracturing. The oil reservoir
is underlain by an active aquifer, which helps maintain reservoir pressure but supports
significant water production. Reservoir simulation, using public-domain, PC-based
software, suggests that infill drilling is an efficient approach to enhanced recovery.
Recent drilling directed by simulation results has shown considerable success in improving
field production rates. Results from the Schaben field demonstration project are likely to
have wide application for independent oil and exploration companies in western Kansas.
