The paper presents the results of experimental studies to quantify the residual pore water content in the core samples of the Bazhenov formation with natural water saturation taken from two wells at the Youzhnoye and Vyngayakhinskoye fields, West Siberia using the direct laboratory methods of the investigation (Dean Stark and evaporation methods). The chemical and mineralogical rock samples compositions obtained using the X-ray diffraction analysis are shown here. The quantitative results of the microcomponents (Li, Be, V, Cr, Co, Ni, Cu, Zn Rb, Cs, U, Pb) and rare earth metals (REE) in the pore waters and in the rock samples are found using mass-spectrometric study (ICP-MC) and presented here for the first time. It also contains the measured values of the rocks cation exchange capacity (Pfeffer method) and results of the pore waters composition of Bazhenov formation obtained via composition analysis of the water extracts. It was found that the gravity groundwater content, presumably capillary water, in the studied rock samples is 0.14-2.35 % (wt), the residual pore water content is 0.42-3.65 % (wt). The total content of Na+, K+ and Cl- in the pore waters of the Bazhenov formation are 17.09-79.21 g/L. Using Pfeffer method it was discovered that the cation exchangers of the studied core samples contain Na+, K+, Ca2+, Mg2+ and Fe3+ that concentrations change with the depth in wells. The measured values of the shales cation-exchange capacity are 3.98-19.50 meq/100g of rock and correspond to the clay minerals content in them.
- Bazhenov formation
- Cation exchange capacity
- Chemical composition of stratal water
- Pore fluid