Ferruginous Methane Waters with Elevated Contents of Iodine, Bromine, and Silicic Acid in Tomsk Oblast
Abstract Generated abstract
This paper identifies and characterizes a group of ferruginous methane mineral waters in Tomsk Oblast, associated with Jurassic and Cretaceous deposits penetrated by exploratory oil well No. 81 in the North Kolpashevo area. On the basis of interval testing, the authors describe sodium chloride waters of varying mineralization, gas composition, pH, inflow rates, and contents of total and ferrous iron, iodine, bromine, and silicic acid. The Tyumen, Vasyugan, and Tara formations show elevated iron and locally elevated iodine, bromine, and silicic acid, while waters from the Kiyalin Formation are less enriched. The authors relate the iron content to leaching of ferrous carbonates in the presence of carbon dioxide and suggest that similar waters may occur elsewhere in Tomsk Oblast.
Full Text
Ferruginous Methane Waters with Elevated Contents of Iodine, Bromine, and Silicic Acid in Tomsk Oblast
V. G. Bykov, E. S. Lisovik
(Presented by the scientific seminar of the Problem Geological Laboratory of TPI)
Tomsk Oblast is rich in diverse mineral waters, the practical use of which, in connection with the development of oil and gas fields, the rapid growth of the oblast’s population, and the absence of nearby resorts, should find broad application.
Within the territory of the oblast, several balneological groups of mineral waters have been identified, possessing a varied general chemical composition and different degrees of mineralization. A new group should be singled out: ferruginous methane waters of chloride–sodium composition, of high and medium mineralization, with elevated contents of iodine, bromine, and silicic acid. This group of mineral waters was penetrated by exploratory oil well No. 81 on the North Kolpashevo area in Jurassic and Cretaceous deposits. The area is located on the right bank of the Ket River, 60 km northeast of the town of Kolpashevo. The well was drilled in the dome of the North Kolpashevo local uplift. In all, 5 intervals were tested in the well.
1. Interval 2426–2436 m (Tyumen Formation, $I_1tm$).
The deposits of the Tyumen Formation are represented by interbedding of argillites, sandstones, and siltstones. The tested interval is represented by medium- and fine-grained, light-gray sandstones, with interbeds of gray and dark-gray siltstone.
The waters confined to the deposits of the Tyumen Formation in this interval are chloride–sodium waters with mineralization of 42.94 g/l. The content of total iron is 100 mg/l. Ferrous iron predominates. Iodine, bromine, and silicic acid occur in amounts close to the lower limit for assigning these waters to mineral, iodine, bromine, and siliceous waters (according to V. V. Ivanov and G. A. Nevraev, 1964). The composition of the dissolved gas is methane ($\mathrm{CH}_4$—76%), pH—7.2. At a dynamic level of 432.0 m, an inflow of water of 12.4 m³/day was obtained.
2. Interval 2340–2350 m (Vasyugan Formation, $I_2vs$).
The deposits of the Vasyugan Formation are represented by interbedding of argillites, sandstones, and siltstones. The tested interval is not characterized by core.
Waters associated with the deposits of the Vasyugan Formation are sodium chloride waters with a mineralization of 11.52 g/L. The total iron content is 44 mg/L. Ferrous iron predominates. Iodine, bromine, and silicic acid occur in elevated amounts. The composition of the dissolved gas is methane-bearing ($\mathrm{CH}_4$—86%); pH is 7.2. At a dynamic level of 913 m, a water inflow of 5.4 m³/day was obtained.
- Interval 2141–2151 m (Tara Formation, $Cr_1tr$).
The deposits of the Tara Formation are represented by fine- and medium-grained, greenish-gray, quartz–feldspar sandstones. The core-sampling interval is not characterized.
Waters associated with the deposits of the Tara Formation are sodium chloride waters with a mineralization of 6.14 g/L. The total iron content is 20.5 mg/L. Ferrous iron predominates. Iodine, bromine, and silicic acid occur in elevated amounts. The composition of the dissolved gas is methane-bearing ($\mathrm{CH}_4$—75%); pH is 8.9. At a dynamic level of 156 m, the water inflow amounted to 26.5 m³/day.
- Intervals 1957–1965 m and 1795–1810 m (Kiyalin Formation, $Cr_1kls$).
The deposits of the Kiyalin Formation are represented by clays with interbeds of sandstones and siltstones.
Waters associated with the deposits of the Kiyalin Formation are sodium chloride waters with mineralization, respectively for the first and second intervals, of 5.33 g/L and 1.69 g/L. The total iron content is 7.5 and 5.0 mg/L. Iodine, bromine, and silicic acid occur in insignificant amounts. The composition of the dissolved gas is methane-bearing ($\mathrm{CH}_4$—81 and 80%); pH is 8.7. During natural flow, water inflows of 108 and 58 m³/day were obtained.
The elevated iron content in the deposits of the Tyumen, Vasyugan, and Tara formations can be explained by processes of leaching of ferrous iron carbonates contained in the rocks in the presence of free carbon dioxide, the amount of which also determines the presence of iron in the waters (A. M. Ovchinnikov, 1963). Under our conditions, the contents of carbon dioxide gas in the waters of the Tyumen, Vasyugan, and Tara formations are, respectively, 281, 149, and 9 mg/L. In waters associated with the deposits of the Kiyalin Formation, carbon dioxide gas was not detected.
This type of water may also be encountered in other districts of Tomsk Oblast.
REFERENCES
- V. V. Ivanov, G. A. Nevraev. Classification of Underground Mineral Waters. Nedra Publishing House, Moscow, 1964.
- A. M. Ovchinnikov. Mineral Waters. Gosgeoltekhizdat, Moscow, 1963.