The Analysis of Geothermal Field Characteristics in Sichuan Basin of China

Abstract

Basic on the selecting thermal logs of 128 wells from 368 measuring temperature wells of oil field, we have established the geothermal distribution in Sichuan Basin of China. For those unsteady-state temperature log data, we have given a statistical analysis correcting method. With the corrected temperature data we have established the geothermal distribution at depth from 1000 m to 6000 m. Viewing these geothermal distribution, we find the following geothermal field characteristics in this Basin. The geo-temperature distributions in the shallow crust and the average geothermal gradient of sedimentary cover in Sichuan Basin show that the geo-temperature distribution in sediments are essentially controlled by the form and undulation of the upper Triassic and the pre-Sinian crystalline basement surface. Higher geotemperatures are located in the areas of elevated basement, such as the middle uplift and the southwestern uplift, whereas lower temperatures are located in the areas of depressed basement, such as the northwestern sag or the eastern high folded belt. Using calculating and estimating method according to data, we have obtained the terrestrial heat-flow in the Basin. The values range from 35 to 80 mW/m2, with a mean value of 62.44mW/m2.