The paper presents the results of laboratory determination of qualitative and quantitative content of different water types in three isolated rock samples of Bazhenov formation found in the area of Nizhnevartovsk Arch (West Siberia, Russia). Composition of formation pore water, composition of exchange cations, as well as cation exchange capacity were also derived from integrated analysis of results provided by direct and indirect laboratory techniques. Total water content was found to vary within 2.15÷7.33 % mass and composition of formation pore water matches measured composition of exchange cations. Moreover, for the first time it was experimentally discovered that Bazhenov rock samples do hold free water and at the same time quantity of chemically bound water in all analyzed rock samples substantially exceeds that of both free and physically bound water. By using direct laboratory technique authors found quantity of residual pore water to vary within 0.3÷0.62 % mass. Determined values of rock cation exchange capacity vary within 14.02÷19.40 mg-eq/100 g of rock, which exceeds previously published data by factor of two, but integrally correspond to composition of rock clay fraction of the analyzed samples. Total salt content (sum of Na, K and Cl ions) in pore water of the studied Bazhenov rock samples falls within 52,93÷83,82 g/L and similarly to both water content and cation exchange capacity varies with depth of Bazhenov formation interval in a single well.