Поиск месторождений нефти и газа с применением радиометрических методов в Азербайджане

Abstract

In the perspective development of Azerbaijan's oil and gas industry, the formation conditions and distribution regularities of radioactive areas in depression zones, which are distinguished by geological-geophysical studies, the deep structure of the Earth's crust, and the relationship between oil and gas content and gamma activity, were clarified by conducting the first radiometric survey in the Kura Depression (in the structures of Kürovdağ, Mişovdağ, and Qalmaz). In subsequent studies, it was determined that all known oil and gas structures coincide with negative gamma anomalies. It was also established that they all have an elongated oval shape, and the level of radioactivity there is 10-15 nSv/h lower compared to the natural background around the structure. Later, most of the structures were checked with other geophysical methods, and the connection between these anomalies and oil and gas content was confirmed. Furthermore, detailed studies were conducted to clarify the reasons for the formation of gamma anomalies in oil and gas fields. Comparison of the obtained materials with seismic data showed that within the defined general contour, separate local zones with low radioactivity are observed. The results of these studies revealed that the formation of gamma anomalies over oil and gas structures occurs due to geochemical and physicochemical processes related to the presence of hydrocarbon deposits in the Earth's crust. Oil fields are characterized by low gamma activity values coinciding with the field's contour. Outside the contour of the oil field, a zone with high gamma activity, creating a ring-shaped effect, is noted. In the case of multilayer hydrocarbon deposits, the anomalous effect corresponds to the middle boundary of the field's contour. The morphological manifestation of gamma activity anomalies is influenced by the lithological composition of the geological rocks. As a result of these studies, the high efficiency of radiometric methods in both the study of the deep structure of the Earth and the search for hydrocarbon deposits has been established. Thus, radiometric methods can be used as direct methods for identifying oil and gas fields. Given the increased scientific and technical level of radiometric research, it is considered useful to reinterpret previously collected materials and conduct new research at a new scientific and technical level using gamma spectrom