Permeability Estimations for Arbuckle Formation in South Central and Southwestern Kansas
The Arbuckle Group saline aquifer is a thick (600–1000 ft) and deeply buried (>3,500 ft) siliceous dolomite with minor interbedded shales. This aquifer is an excellent candidate for waste and back-flow water disposal and potential CO2 geological storage due to stratigraphic isolation from freshwater aquifers, and very limited oil and gas production in the areas studied. With recent developments of Mississippian unconventional Lime play and historically high water cuts in Kansas and Oklahoma the demand for fluid disposal is growing in the region; therefore, it is important to estimate Arbuckle formation injectivity and provide estimations for reservoir permeability, fracture properties, fracture gradients, maximum allowable pressures, and others. This work is focused on permeability estimations based on multiple data sets, including core measurements, core fracture and features studies, log analysis, Step Rate Test (SRT) and Drill Stem Test (DST) analysis, Arbuckle aquifer water level changes, seismic data, and others. Several selected oil fields and areas, such as Wellington Field, Bemis Shuts Field, Cutter Field, and others were used as case studies to demonstrate differences and similarities in reservoir properties across south-central and south-western Kansas. It was found that permeability estimations which were based on core and well log analysis have to be correlated with well tests, especially for target injection zones, where the discrepancy between core and log analysis estimations and well test analysis could vary one or, in some cases, two orders of magnitude. This happens likely due to existing major joint and fracture network system which is very difficult to account for using conventional methods.
AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015