Geothermal energy potential of the Pliocene complex of the Absheron peninsula

Currently, due to environmental concerns the use of non-conventional energy resources came to the foreground. This makes identification and use of areas with high potential for geothermal energy to be the actual problem. The most appropriate way to solve this problem is to use the geothermal energy of thermal waters.

On the territory of Absheron peninsula thermal waters are widely spread in sediments of absheron stage and productive strata. The variation of the geothermal gradient and distribution of heat flow within the depths of the development of this complexes were studied. The data from many oil wells show that, thermal waters with the temperature of above 20°C, have regional evolution within depths more than 110-180 meters. On the Absheron peninsula thermal waters discovered at various depths by wells and natural springs. The peninsular part of Absheron, of the drilled depth of east village of Hovsan, temperature of mineralized waters reaches 100-135°C. Thermal waters by pressure were revealed in some places of Absheron peninsula. At the Bibi-Heybat, directly from Baku, were fountained chloride-bicarbonatesodium water with a salinity of 16.5 g/l with a temperature of 71°C and a flow rate of 450 m3 /day. In Guzdek, wells produced water with a temperature of more than 50-65°C. Hot water is also fountained from the wells in the Kara-Heybat, Chilov island and etc. With the depth, temperature of thermal waters increases and mineralization decreases. On the basis of information from tens of wells, was analyzed in some structure of Absheron, dependence of temperature with depth and graphics were compiled. In order to reveal of temperature distribution with the depth, regression line was compiled and regression equation were developed, which determines the temperature gradient. From these figures, it is clear that with increasing depth the value of the geothermal gradient decreases. This decrease is explained mainly by the sedimentation process in this basin. The process of avalanche sedimentation in the middle Pliocene weakened heat flow coming from the basement. Variation trend of temperature vs depth at short intervals is advisable to introduce a straight line, because, in the layers with a small capacity of temperature distribution on the depth is straight and in many cases from the regression equation is determined the geothermal gradient.

In the present study, based on the forecast reserves of thermal water (20,000 m3/day) and the values of their temperature (20-90°C), an assessment of the value of geothermal energy of thermal waters of Absheron Peninsula is given.

The paper estimates the predictive (P1, P2) and exploitation (C3) geothermal resources. Based on the model of "The volume heat content of the porous reservoirs" it is estimated the density of geothermal resources at the depths of up to 6000 meters. As a case study, the temperature vs depth variation on the Lokbatan-Puta-Qushkhana deposit was studied and their spatial values distributions of various depths were mapped.

Productive strata are the most well-studied sedimentary layers in Azerbaijan. In this paper, map of temperature distribution on the top of productive strata was compiled. On the basis of this map, as described above was assessed geothermal energy resources for productive strata of Absheron.

The results show that in the depths of this area there are a lot of energy for use in heating systems and agriculture. For the use of geothermal energy, there are various technologies and technical means. The paper substantiates the feasibility of using heat pumps in Azerbaijan.

08.02.2019     Print  Print