Seven deposits of groundwater, which are located in the slope side of the Caspian depression in the Lower Cretaceous Albian aquifer complex, were investigated and put into operation to provide drinking and industrial water supply for oil and gas production facilities. The well-fields are located within the plateau, which was dissected by valleys of rivers and streams. The aquifer complex is composed of different-grain sands with interlayers of clay with a total thickness of about 200 m. It is confined or unconfined on different areas. Its groundwaters are interconnected with river waters in some places. The groundwaters of the aquifer complex are fresh or brackish with mineralization of 0.2 ÷ 3.2 g/l. The estimated volume of the exploitable groundwater resources of seven well-fields reaches 1.03 m3/s.
Groundwater intakes are operating under conditions of their mutual influence. In addition, the abstraction of the brackish groundwater for production and technical purposes can attract the fresh groundwaters to these industrial water intakes. But the use of fresh drinking water for production and technical water supply is prohibited by the legislation of Kazakhstan.
Thus, a rational exploitation of these groundwater well-fields, taking into account environmental limitations, is an actual problem.
An observational network of groundwater monitoring has been created in all groundwater well-fields. To assess and predict the state of the well-fields and the aquifer complex as a whole, in 2014, in the ModFLOW Flax software, a permanently operating mathematical model (POM) of seven groundwater fields was built and put into operation. POM is operated to ensure promptly reliable assessment and predictive information on changes in the hydrogeodynamic and hydrogeochemical state of water intakes and of the Albian aquifer complex as a whole.
The result of solving the geofiltration and geomigration tasks on the POM allow anticipating the development of undesirable hydrogeodynamic and hydrochemical processes, to develop recommendations for optimizing the monitoring network and the regime of groundwater well-field's abstraction to eliminate the risks of special hydrochemical situations for the industrial groundwater supply on the oil and gas production facilities. This can significantly reduce the risks of inadvertent use of fresh groundwater for production and technical purposes and provide the sustainable development of the oil production sector.