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Zhuma Kadyrgaliyeva, Atyrauhydrogeology Company (Kazakhstan)
Viktor Chshen, Atyrauhydrogeology Company (Kazakhstan)
Vyacheslav Zavaley, Kazakh National Technical University named (Kazakhstan)
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Within North-East Caspian Sea region (Atyrau oblast, Republic of Kazakhstan) low mineralized underground waters with mineralization up to 3-4 g/dm3 may be of benefit to use not only for technical and agricultural water supply but also for domestic water supply.
The region is poor with surface waters. River network is developed in south-west and north-east, but the most part of the territory does not have any permanent water courses. Therefore, river waters can not always be considered as reliable sources of domestic water supply.
The longest water pipe routed in the region is Khigach(Volga)- Mangistau which transports fresh water to Mangistau supplying with water many population centers and oil-fields on it's way. However, due to rise of Caspian Sea level the water pipe is constantly incurred by rundown-surge processes with surge height of 1.5-2.6m which results to instability of territory water supply and makes technical operation and maintenance complicated.
Prior to 1982 (Bali, Tugarakchan) the hydrogeological section was thoroughly examined only up to the depth of 500-520m. The reason was little requirement and absence of required machinery equipment. With exposed thickness of Alb-Senomanian formations (100-220m) the effective thickness of productive strata was 60-132m. Underground waters were flowing, hydraulic head was 356,0m including above the ground surface - (27.0-29.0). Flow rates of wells were up to 30dm /s, with level lowering - 22.2m. Sulphate chloride sodium waters with mineralization on Bali field area -3g/dm3, Tugarakchan area -3,6g/dm3. Calculated hydrogeological parameters were: water transmissibility - 310 and 338m2/day, piezoconductivity- 3.5 and I,4xl05m2/day, effective thickness - 132 and 60 m.
1982 through 1984 the hydrogeological investigations were carried out in South-Emba artesian basin at Zhanasu field. Requirement of water exceeded the earlier approved water reserves twice all over the basin and made 119,000m3/day, which caused the necessity to study in details the hydrogeological section for fullthickness. In addition, testing of upper and lower parts was performed separately in one point using two tiered wells with a depth of 550 and 820 m. Such method confirmed the accuracy of the chosen decision. Calculated load as achieved for each water intake point represented by two wells was taken as 92 dm/s.
New approach to the hydrogeological model of South-Emba basin has changed the concept of calculated hydrogeological parameters of aquifer system and Zhanasu field. The parameters are shown as follows: filtration coefficient -3,25m/day, effective thickness -292m, water transmissibility - 994m2/day, piezoconductivity - 1,65xl06m2/day. Obtained data prove big potentialities of South-emba artesian basin.
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