Method of locating oil and gas horizons using a wellbore heat flow log

摘要

Oil and gas horizons in a wellbore are located by establishing from thermal logs thermal gradients for successive intervals free of drilling- induced thermal disturbances, identifying the mineral abundances surrounding the wellbore at each of said intervals, establishing ideal thermal conductivities for said mineral abundances based on assumptions that sand-rich formations have high thermal conductivities and are water- bearing and that shale-rich formations have low conductivities, determining an ideal heat flow at each interval by multiplying the thermal gradient at such interval by the ideal thermal conductivity of the mineral abundances at the interval, determining the average ideal heat flow for all of the intervals, and identifying the zones of the wellbore exhibiting anomalous ideal heat flows that are higher than the average heat flow.