Особенности ионно-солевого состава подземных вод венд-нижнекембрийских отложений Среднеботуобинского нефтегазоконденсатного месторождения на стадии катагенеза

Abstract

The salt water omposition of underground brines of the Vendian - Lower Cambrian sections of the Middle Botuoba oil-gas-condensate field during the catagenesis stage is considered; the peculiarity of which is the presence of polygenic waters in certain block traps of B5 and Б1 levels: sodium sulfate, sodium hydrogencarbonate and chlorine-magnesium genetic types together with the prevailing chlorine-calcium genetic type. The zoning of the groundwater of the strata by mineralization and four genetic types of groundwater has been carried out. The directions of water entry into the reservoirs formed at the stage of catagenesis and entering together with hydrocarbons in the corresponding traps are established. It is shown that, while maintaining the mechanism of formation of the salt water composition in the "rock-water" system, the polygenicity of the formation waters present simultaneously in one reservoir layer reflects a regular change in the components of their chemical composition during the transition from the artesian basin to the oil and gas basin. The most sensitive ions of the chemical composition of groundwater, reflecting the transition of the artesian basin to the new geological state of the catagenesis stage, are sulfate, bicarbonate, and sodium ions.