Wettability of organic-rich source rocks: case study on Bazhenov Formation (Abalak-Bazhenov group)

Abstract

Abstract. In this work, we have investigated the wettability of Bazhenov Formation rock samples using a nuclear magnetic resonance (NMR), the methods of vapor adsorption, and wetting contact angle. We have conducted the petrographic description of rocks using ultra-thin sections and scanning electron microscopy (SEM). In addition, we used data on the organic content (TOC) obtained by the Rock-Eval method and the results of lithological typing on thin sections for detailed analysis of NMR and contact angle methods results. Thus, for target rock, the groups with a similar rock wettability were highlighted by the lithological description of thin sections. The calculation of the wetting angle provided an initial assessment of the surface wettability of the rock and made it possible to establish the relationship between the wetting angle and the TOC, which is relevant for rocks of the Abalak-Bazhenov group. The NMR method described the core plug wettability proved to be less sensitive to the rock lithotype and organic matter (OM) texture in the rock and, therefore, used for the integral characterization of core plugs. Correlations of calculated wetting angle and adsorption wettability index vs. TOC and OM texture illustrated the dependence of rock wettability behavior on both the lithological specifics and the OM properties.

Investigation of Source Rock Heating and Structural Changes in the Electromagnetic Fields Using Experimental and Mathematical Modeling

“…Two major oil-prone formations located within The Russian Federation are the of Bazhenov and Domanic Formations. Both formations are characterized by very low values of porosity, permeability and complex structure of void space [1][2][3].…”

Rock–Fluid Interactions of Alkyl Ether Carboxylate Surfactants with Carbonates: Wettability Alteration, ζ-Potential, and Adsorption

“…Rock microstructure and lithology were characterized through petrographical thin-section (30 μm) analysis with a ZEISS Axioscope 5 polarizing microscope. High-resolution two-dimensional (2D) microstructural visualization of the rock sample surface was done with a Thermo Fisher Scientific Quattro S scanning electron microscope (SEM). − SEM images were done before aging, after aging in oil, and after treatment with surfactants to show the qualitative changes in wettability and explain the wettability alteration mechanism …”

Upper Jurassic–Lower Cretaceous Source Rocks in the North of Western Siberia: Comprehensive Geochemical Characterization and Reconstruction of Paleo-Sedimentation Conditions

“…According to our results, L-3 is characterized by a strong dominance of thin laminas and lenticular inclusions of kerogen (Figure 3C,G), whereas other lithological types host tiny dispersed or patchy organic matter, with a minor role of lenticular inclusions (Figure 3). Variations of organic matter shape cause differences in petrophysical properties of rocks, such as mechanical anisotropy, wettability [37], and many others. Different structure and distribution patterns are determined by organic matter type and origin, which is further investigated in the paper.…”