ABSTRACT: Heat Flow and Thermal Conductivity Variations and Their Effect on Thermal Maturation in the Anadarko Basin, Oklahoma

CARTER, LARRY S., Southern Methodist University, TX

Heat flow values have been calculated for seven locations in the Anadarko basin area of Oklahoma. Three of the locations are on the northern shelf, three are in the deep basin, and one is in the frontal part of the Wichita Uplift. The heat flow was calculated from temperature logs run at the seven locations and conductivity measurements from core in or near the sites. High precision temperature logs (0.1-0.5 m measurement interval) were run in wells at or close to thermal equilibrium.

Nearly 300 conductivity measurements were made on vertical core plugs taken from various stratigraphic intervals within the basin. Conductivities range from 0.9 W/m/K for some shales to over 6.6 W/m/K for some sandstones. Permian red shales have a significantly higher conductivity than Pennsylvanian shales and organic-rich shales of the lower Paleozoic. Pennsylvanian "granite" and "carbonate wash" sections have high conductivities ranging up to 6.3 W/m/K, in strong contrast to the laterally equivalent shales away from the uplift.

The heat flow ranges from 39 to 62 mW/sq. meters and generally decreases from north to south. Variation of the heat flow is primarily due to the radiogenic content of the basement rock. The lateral lithology changes, and resulting thermal conductivity variations, combined with the heat flow variations, have affected thermal maturation patterns in the basin. For example, vitrinite reflectance values of the Woodford Shale are higher north of the deepest part of the basin. The high thermal conductivity of the "granite wash" sections result in a lower mean gradient along the south (deep) side of the basin. Lower thermal conductivity and increasing heat flow to the north result in a higher mean gradient and increased thermal maturation under the shale sections north of the deepest part of he basin.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)