The Objective of this research is to predict changes in earth surface temperatures using subsurface temperatures, and model the heat flow causing these temperature changes. The research work Performed in this project required temperature data from deep coabled methane wells which were obtained using a winch-suspended temperature sonde. Sonde data were transmitted to a surface recorder and computer for observation and storage.

Digital test data from 41 logged wells were used as input to a heat flow model. Anomalies in the measured temperature gradients were compared with open-hole logs to verify lithology. Temperature-depth presentations were made for all logged wells. Samples of typical subsurface materials were taken from rock cores for measurement of their thermal properties.

Temperature VS. depth and lithologic data collected in this study were used as inputs to a mathematical heat flow model. The model was designed to solve the one-dimensional heat conduction equation in an inverse fashion, and to provide the ground surface temperature (GST) History during the time period prior to data collection.

Because the real subsurface environment is heterogeneous in three dimensions, the use of a one-dimensional model can cause spurious noise in individual GST histories. Recent work by Shen et al.(1994) concerned this issue in part, and recommended that the ensemble of GST histories obtained via the mathematical model for various wells in a region be examined for general consistencies and trends.