Approximate Geothermal Gradients in the North Sea Basin

Abstract

APPROXIMATE geothermal gradients were determined from bottom hole temperatures for eighty wells in the North Sea Basin, which comprise about 30% of all post-1963 North Sea Basin wildcats. The wells are distributed as follows: onshore Netherlands, fifteen; offshore Netherlands, five; onshore Germany, one; offshore Germany, ten; offshore Denmark, one; offshore Norway, nine; offshore United Kingdom, thirty-nine. The data are displayed on the depth-temperature graph, Fig. 1, and the geothermal gradient contour map, Fig. 2. Before the determination of the geothermal gradients, an assumed surface temperature of 10° C was subtracted from the measured borehole temperature, and drilled depths were converted to depths below the sea bottom or land surface.