The Anadarko basin of Oklahoma is a two-stage Paleozoic cratonic basin with
as much as 12 km (7.5 mi) or more of sedimentary fill. We present a presen
t-day thermal model of the basin based on lithologic analysis at 3-m (10-ft
) intervals in 63 wells, heat flow measurements at seven sites, and in-situ
thermal conductivity calibration of the sediment section at two sites. We
do not use BHT (bottom-hole temperature) information in the process, but we
do, at the end of the process, compare the independently predicted tempera
tures to BHT information. The in-situ calibration of thermal conductivity w
as accomplished using detailed temperature logs and represents a new practi
cal application for evaluating basin thermal characteristics. Shale exerts
the most control on the temperature distribution because it is the most abu
ndant lithology and has the lowest thermal conductivity. Shale comprises 47
% by volume of rock in the basin and represents 75% of total thermal resist
ance, directly related to temperature gradient; therefore, shale dominates
the thermal structure of the basin. Thus, the problems in sampling and in c
haracterizing the in-situ thermal conductivity of shale from laboratory mea
surements represent a major limitation in basin thermal analysis; are use t
he in-situ calibration approach as a way to address the difficulty: The tem
peratures calculated do not mimic the structure of the sediments; i.e., the
hottest area on a given age horizon in the lower Paleozoic is not in the m
ost deeply buried part of the Anadarko basin. The combination of decreasing
heat flow toward the Wichita Mountains and the facies changes in the Penns
ylvanian units from marine shale (low thermal conductivity) in the basin to
the granite wash (high thermal conductivity) toward the uplift results in
the highest temperatures being displaced about 50 km (31 mi) northward into
the basin. The pattern of vitrinite reflectance in the Woodford Shale is v
irtually identical to the present-day reconstructed temperature pattern; th
erefore, we conclude that the thermal pattern is and has been dominated by
conductive heat transport.