The Naftalan field is located in the Yevlakh-Aghjabadi lowland of the Ganja oil and gas area in Goranboy region, south of the Goran railway station. The Naftalan field, 5 km long and 1.5-2 km wide, is a tectonically asymmetric brachianticlinal fold.
According to the Upper Cretaceous sediments the Naftalan structure is an anticline elongated in the meridional direction. The stretching direction of the structure is meridional in the north and slightly NW to the south. The northern pericline is separated from the Godekboz structure by a saddle. The eastern wing is continuous and gradually turns into a monocline. The dimensions of the structure are 14.5×5.5 km on the 3050 m isohyps and from the tectonic point of view, it is an asymmetric brachy anticlinal fold. Parallel faults are observed at a distance of 400-700 m from each other. The amplitude of the fault increases from 800-850 m in the south to 1500-1550 m in the north.
From 1888 until the nationalisation of the oil industry, there was no information on the exploitation of wells. The healing property of oil has attracted the attention of the local people since as early as 13th century when its showed on the land’s surface for the first time. In 1868, the German oil engineer I. Yeger drilled a well here and organised the production of Naftalan oil. After studying the healing properties of the oil, he opened the Naftalan medical ointment plant. Crude oil exported to Western countries and the plant’s products soon became popular in Europe. Since the end of the 19th century, ointments based on Naftalan oil have been patented and imported to Russia alongside German products. Academician Y. Mammadaliyev discovered that naphthenic hydrocarbons contained in unique Naftalan oil produces its healing properties.
In 1929, restoration of mines and abandoned oil wells began in Naftalan, taking into account the development of the resort area, including structural exploration wells to explore the subsoil, determine the contours of therapeutic oil horizons and search for possible deeper oil and gas horizons.
The geological structure of the area has been studied through geophysical methods, structural mapping, exploration and deep drilling data. Until 2008, a total of 140 wells had been drilled, including 17 wells drilled into oil and gas-bearing horizons. The Godekboz well (well No. 3M) was drilled in 1977-1980 and the North Naftalan-2M well was drilled in 2000-2004.Overall gravimetric mapping work was conducted between 1947-1949 and extensive work was carried out in 1974 and 1976. The compilation of the obtained results took place in 1961 and 1974. Electrical exploration was conducted in various years and MTZ and MTP works were carried out in 1984 and 1988 to study the tectonics of Upper Paleozoic sediments. Seismic exploration activities were conducted in 1945-1949, 1959, 1966-1968, 1977-1978, and 1987-1992. In 2010, seismic exploration works, and gravimetric observations were conducted in the area. In 2013, the evaluation of three-dimensional (3D) seismic exploration materials in the Naftalan-Northern Naftalan area resulted in the preparation of structural maps based on reflections on the SHs representing the Upper Tertiary, Middle Eocene and approximately the VI horizons of the Maykop. In 2022, the reprocessing and evaluation of the data from the three-dimensional (3D) seismic exploration conducted in the Naftalan-Northern Naftalan area revealed a detailed geological structure of the Naftalan and Northern Naftalan structures. These structures are characterized as large-scale, primarily unit anticlines aligned with fractures in the structural trend, providing a comprehensive understanding of the geological composition.
In the Naftalan field, within the Maykop formations, several oil-bearing horizons have been discovered. Significant heavy oil has been extracted from the upper three horizons (I, marl, II), from the lower horizons (III, IV, V, and VI) have produced relatively light oil. Although the initial production rates were between 40-60 tons per day, the production quickly decreased to 5-3 tons.
In 1930-1935, in total 27 deep exploration and 4 appraisal wells were drilled in the Naftalan field. As a result of these works, in 1942, fuel oil horizons were discovered in the section below the therapeutic oil horizons.
Fuel oil production began in 1942. However, due to their low debit, their industrial development has not been widespread. At the end of 1962, Azneft decided to stop production of this type of oil in order to expand the resort area while maintaining the properties of the treatment oil. The density (specific gravity) of the healing oil is 0.945-0.960 and requires a high ignition temperature, while the specific gravity of the fuel oil is 0.860-0.900 and requires a normal ignition temperature. Healing oil is black, paraffin-free, consisting mainly of oils, kerosene and ligroin (product of primary oil refining), has a high molecular weight (370-391) and is one of the active oils. Fuel oil has a low molecular weight (299).
There are plans to drill an exploration well in the field with the aim of studying the prospectivity of Mesozoic formations in 2024. If the results of the drilled well are positive, it may lead to an increase in the estimated remaining recoverable reserves in the reservoir. In that case, there might be plans to drill several more wells in the future.
The industrial development of the Naftalan field began in 1950, and the production data were registered in the same year. As of the 1st of January 2024, 94 wells have been drilled in the field, producing a total of 753,000 tons of oil, including 563,000 tons of Naftalan therapeutic and 19,000 tons of fuel oil. At present, 18 wells are in operation. The extracted oil is sold to medical centres operating in the area. Although no fuel oil is extracted, the Naftalan field is operated by A. Amirov OGPD of SOCAR’s Azneft PU.