MODERN ALGORITHMS AND SOFTWARE FOR INTERPRETATION OF RESISTIVITY LOGGING DATA

The electrodynamics of geological media investigates the interrelations of resistivity logging signals and properties of fluid-containing rocks and creates innovative well logging technologies. Its development is inextricably linked with modern techniques for mathematical modeling and quantitative interpretation of high-precision data. In order to increase the information content of galvanic and electromagnetic logging, we have developed algorithms and software for numerical simulation and inversion of field data. In our study of the Cretaceous and Jurassic deposits of West Siberia, a quantitative interpretation of high-frequency electromagnetic and lateral logging signals was carried out. To create geoelectric models, we interpreted the field resistivity logging data by an unconventional quantitative technique based on their joint numerical inversion and estimations of the vertical resistivity of permeable deposits. Another line of our research was aimed at a scientific substantiation of a new technology for mapping and spatial tracking of lateral heterogeneities and oil-promising zones in the Bazhenov Formation. The aim was achieved by using the TEM sounding data on a spatially distributed system of directional and horizontal wells

Fast solution of two-dimensional inverse problem of high-frequency electromagnetic logging in oil-gas boreholes

The paper is dedicated to development of physical-mathematical tools of interpretation of the data of electromagnetic logging in oil-gas boreholes. Program-algorithmic means of numerical inversion of relative gain-phase characteristics in axis-symmetric models have been worked out. Algorithm of solving fast inverse problem is based on linear inversion and includes analysis of a matrix of sensitivities of the measured signals to model parameters. Inversion is accompanied by determination of areas of ambiguity of parameters recovery. High productivity of two-dimensional direct problem made possible realization of alternative approach to inversion based on plotting and analysis of all the ensemble of quasi-solutions of two-dimensional inverse problem. Elaborated algorithms give possibility to determine geo-electric parameters of penetration zone and the layer and estimate their inaccuracies. Experiments on recovery of electro-conductivity in typical models of collectors on synthetic and experimental data have been performed

Hollow spherical and nanosheet-base BN nanoparticles as perspective additives to oil lubricants: Correlation between large-scale friction behavior and in situ TEM compression testing

In the present study we utilized h-BN nanoparticles (NPs) with different morphologies (hollow NPs with smooth surface (H-BNNPs), solid NPs with “pompon”-like or petalled structure (P-BNNPs), and globular NPs formed by numerous thin h-BN nanosheets (N-BNNPs)) as additives to PAO6 oil. Two sliding 100Cr6 surfaces were tested in the presence of PAO6+BNNP lubricants with 0.1% and 0.01% of BNNPs. The positive effect of BNNP additives increased along the row P-BNNPs → H-BNNPs → N-BNNPs. Utilization of N-BNNPs permitted to decrease noticeably the friction coefficient from 0.1 to 0.06 and reduce significantly the wear rate. In situ mechanical TEM tests were also performed to visualize and correlate the mechanical properties of individual h-BN NPs to their large-scale friction behavior.</p

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

BN/Ag hybrid nanomaterials (HNMs) and their possible applications as novel active catalysts and antibacterial agents are investigated. BN/Ag nanoparticle (NP) hybrids were fabricated using two methods: (i) chemical vapour deposition (CVD) of BN NPs in the presence of Ag vapours, and (ii) ultraviolet (UV) decomposition of AgNO3 in a suspension of BN NPs. The hybrid microstructures were studied by high-resolution transmission electron microscopy (HRTEM), high-angular dark field scanning TEM imaging paired with energy dispersion X-ray (EDX) mapping, X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FTIR). They were also characterized in terms of thermal stability, Ag+ ion release, catalytic and antibacterial activities. The materials synthesized via UV decomposition of AgNO3 demonstrated a much better catalytic activity in comparison to those prepared using the CVD method. The best catalytic characteristics (100% methanol conversion at 350 °C) were achieved using the UV BN/Ag HNMs without preliminary annealing at 600 °C in an oxidizing atmosphere. Both types of the BN/Ag HNMs possess a profound antibacterial effect against Escherichia coli K-261 bacteria