Estimating in-situ thermal conductivity from log data

Abstract

Hole 857C penetrated about 470 m of turbidite sediments. Below the sediments the hole intersected a series of basaltic sills interbedded with sediments. Hole 857C is located south of an active hydrothermal vent field in an area where seafloor heat flow measurements show values exceeding 0.8 W/m2. This hole was successfully logged with the seismic and lithodensity tool string. Open-hole temperatures at a depth of 480 mbsf are as high as 222°C. Varying the grain thermal conductivity between 2.6 and 3.2 W/m-K results in a range of thermal conductivity profiles that predict temperatures that are in agreement with observed vent fluid temperatures. -from Authors