Thermal
Regime of the Midcontinent El Dorado Oil Field (Kansas) Interpreted from
High-
Resolution
Temperature Logs
By
Jason R. McKenna1,
Daniel F. Merriam2, and David D. Blackwell1
1Department of Geological Sciences, Southern
Methodist University, Dallas, Texas 75275
2Kansas Geological Survey, University of Kansas,
Lawrence, Kansas 66047
The giant, multizone-producing El Dorado oil field
(Butler County in south-central Kansas) was discovered on the Nemaha Anticline
in 1915. Early indications from bottomhole (BHTs) and drillstem (DSTs)
temperature measurements indicated a close relationship between the anticlinal
structure and higher subsurface temperatures. Recently, a suite of high-
resolution
temperature logs was made from shut-in wells on the East and West Shumway domes
in the field to confirm the three-dimensional thermal modeling. The temperature
logs generally are conductive, equilibrium profiles demonstrating that these
types of logs can provide reliable, equilibrium-temperature measurements in an
active petroleum setting. Lower temperatures measured in several of the wells on
the East Shumway Dome seem to be the result of a significant change in thermal
gradient from mass transport of hydrocarbons and in situ thermal conductivity
changes related to the presence of hydrocarbons and not to interwell lithologic
variability. An analysis of the
high-
resolution
temperature logs and log-header BHTs taken near the top of the
Kansas City Group (Upper Pennsylvanian) and Arbuckle Group (Lower Ordovician)
productive zones on the West Shumway Dome indicate that the anomalously high BHT
data are close to the actual formation temperature substantiating that the
higher temperatures encompass a broader region on the dome than previously
assumed.AAPG Search and Discovery Article #90010©2003 AAPG Southwest Section Meeting, Fort Worth, Texas, March 1-4, 2003