Geology, geography and global energy

Scientific and Technical Journal

Forecasting geoecological complications in marine exploration and mining activities

2013. №2, pp. 125-143

Serebryakov Andrey O.  - Senior Lecture, Astrakhan State University, 1 Shaumyan sq., Astrakhan, Russian Federation, 414000,,

In the post-salt hydrogeological floor stand Quaternary, Neogene, Paleogene, Upper, Lower Cretaceous, Jurassic, Triassic and Upper Permian aquifer systems. Reservoir rocks are represented by clayey sand, sandstone, siltstone, and limestone. chalk and marl. Aquitard are dense clays and mudstones. Reservoir properties and thickness of permeable horizons vary widely. Voids ratio ranging from 5–7 to 15–28 %. Production rates vary from a few to a 95–600 m3/day. All aquifers except the very top are the high-pressure. Universal development of salt water and brine calcium chloride-type mineralization which ranges from 1 70 g / l in the upper part of the section up to 242 – 310 g / l and more – at the bottom. In the Quaternary alluvial deposits observed small lenses of fresh water with a salinity of 1–3 g / l. Highly mineralized water at depths greater than 1000 m contain elevated concentrations of trace constituents. Inside halogen Kungurian strata developed lenses and interlayers weak bostssmentirovannyh sulfagio tsrrigsnnyh-carbonate-rock, at the opening of which in some cases occurred rapopgyuyavleiiya. Brine flow rates at eamoizlivs ranging from 2,5 to 41,3 m3 per day. Isolation of sulfate-terrigeinyh lenses by area and section leads to the formation of AVPD. The coefficients of the anomaly may reach 1,7–1,9. Brine refers to chloride-calcium type with density 1190–1220 kg/m3 and mineralization of up to 510 g / l. Subsalt hydrogeological tgazh Elysion hydrodynamic regime begins thickness galopelitovyh (clay) Sakmar-Artinskian deposits that do not have explicit kollekgorov. They are the top aquitard subsalt hydrogeological floor, reinforcing regional screening properties halogen column. Bashkirian limestone sredpekamennougolnogo age and Lower rocks constitute the upper part of the hydrogeological subsalt floor. The total thickness of the carbonate complex, according to drilling up to 2000 m permeable rocks are porous and permeable limestone, dolomite, to varying degrees. Collectors are separated dense varieties of carbonate rocks. Debits flowing wells vary from 0,7 to 350 m3/day. The complex is characterized by Elysion hydrodynamic regime. Water migrates from the central part of the Caspian basin to the sides, where they are hidden unloading. Replacement of carbonate type cut on the carbonate-terrigenous creates hydraulic resistance on the way of the flow, which provides conditions for hydrodynamic isolation water drive reservoir, the concentration of produced energy and the formation of AVPD. The coefficient of the anomalous pressure water 1,5–1,55. Waters are characterized by high gas saturation and hydrocarbon-ssrovodorodno-uglskislym vodorastvorsnnogo gas composition. Feature-salt bearing floor is the existence of two genetic types of underground water: calcium chloride and sodium bicarbonate.

Key words: geo-ecology,hydrogeology,shelf set,floor,hydrochemistry,geological survey