Assessment of fresh groundwater vulnerability to contamination caused by production operations in oil and gas fields of Nizhnevartovsk Region (Western Siberia)

Groundwater quality is possible to provide under the condition of aquifers effective protection from surface contamination and bottom pollution prevention in the areas of intense oil-gas production operations. Qualitative and quantitative assessment of groundwater vulnerability is based on regional characteristics of lithological composition and thickness of impermeable deposits in unsaturated zone and overlying deposits. The correlation of head and water table levels, absorption capacity of soils and clay rocks are also considered. An integrated approach to natural vulnerability analysis of groundwater has been presented. It suggests a combination of three most common methods. Based on performed calculations, the map has been made to plot fresh groundwater vulnerability of Atlym-Novomikhailovsk aquifer system (Nizhnevaryovsk Region, Khanty-Mansiysk Autonomus Okrug).