Shallow and Deep Temperatures in the South-Caspian Basin

Abstract

Distribution of shallow and deep temperatures in the sedimentary cover of the South Caspian Basin (SCB) is addressed. Analysis of soil temperature data recorded in meteostations of Azerbaijan and its neighboring regions provide clues as to the temperatures at near surface layers.  Such layers, where seasonal variations of temperatures converge to near-stable values have been designated as the “neutral” layer. In many localities, the bottom parts of such layers extend to depths of around 20 m. In addition, temperature data of over 150 wells, obtained from depths varying from 100 to 6000 m in oil and gas bearing areas of Azerbaijan have been used in assessment of deep temperatures. Data bases were generated for study of lateral temperature fields (in other words, geothermal sections) at depths of 500, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 meters. The results reveal that low temperature areas extend from the north-west to south-east and covers low-lying areas of SCB. Thus, local temperature minimums (30-35°С) are found in Neftchala area, the other larger temperature minimum (35-40°С) covers the structures of Dyvanni-deniz and Here-Zire adasy and expands along the strip Khamamdag deniz, Garasu, Sangi Mugan, Aran deniz. On the other hand, local temperature maximums are observed along the Kura Depression: in Ajinour area with an amplitude of 80°С; to the west of Kyurdamir in Sorsor and Amirarkh areas with an amplitude of 65-70°С; in Sarkhanbeyli-Garabagly-Kyurovdag areas with an amplitude of 60-65°С.