This paper is dedicated to expanding the application scope of X-ray fluorescence (XRF) analysis of drill cuttings in the Achimov deposits of the Urengoy oil and gas condensate field. The first part of the study addressed the lithogeochemical typing of the section using XRF data from drill cuttings. The second part presents a methodology for the real-time evaluation of formation reservoir properties during horizontal well drilling with a minimal logging-while-drilling (LWD) suite (gamma ray logging only, or its combination with resistivity measurements). The authors propose a simplified mathematical model for evaluating porosity based on the concentration of a single element indicator – zinc (Zn). The results of “blind testing” of the model on an exploratory well from an adjacent area confirm its reliability. The practical significance of implementing this porosity evaluation methodology for drilling horizontal wells with a minimal LWD suite is substantiated.
The 4th Annual Conference “The Potential of the North of Western Siberia: Resources and Technologies” organized by NOVATEK PJSC, took place in Tyumen, Russia on June 16–17, 2026.
The pre-Jurassic complex (PJC) of the Frolovskaya mega-depression in Western Siberia is a promising direction for expanding the resource base: 68 fields are currently on the state balance, holding geological reserves of approximately 965 million tonnes of oil equivalent. This paper summarizes experience in interpreting wide-azimuth 3D seismic data to study the structure and petroleum potential of the complex over an area characterized by 10 surveys (covering more than 2800 km²), 90 exploration wells, and over 500 production wells. It is shown that a reliable structural model of the PJC is achieved through full-azimuth anisotropic depth migration, which improves the focusing of dipping reflections and the suppression of multiples under conditions of erosional relief and a weathering crust. For areas of acid volcanic rocks development of Late Permian–Early Triassic age, a relationship has been established between lithological composition (tuffs, rhyolites, metarhyolites) and elastic properties: the most promising reservoirs are porous tuffs with reduced acoustic impedance, traceable from simultaneous seismic inversion data; reservoirs with a complex pore-space type are not reliably distinguished by elastic properties. Beyond the volcanic areas, a probabilistic forecast of the compositional makeup of the PJC’s near-top section is proposed, using Gaussian discriminant analysis applied to P-impedance and Vp/Vs maps, based on a core elasticproperty database (more than 360 samples, 10 petroclasses). The integration of seismic exploration, petrophysics, and probabilistic modeling reduces drilling geological risks and improves the efficiency of exploration operations.
The technologies of joint exploitation of oil reservoirs in a single well grid are widely used in the development of multi-layer deposits. Simultaneous or dual completion operation of several oil-bearing facilities significantly reduces drilling and repair costs, and new facilities are put into development faster and at lower cost. However, these technologies require the mandatory introduction of separate accounting systems for the liquids taken from each reservoir. The first part of this publication provides a brief overview of modern methods for solving the problem of determining the relative flow rates of reservoirs during joint operation in a producing well. The advantages and disadvantages of engineering approaches to solving the problem, mathematical modeling methods, and technological methods for separate accounting of reservoir production are considered. The second part of the article describes an algorithm for conducting a chemical analytical study of well production in order to determine the contribution of productive formations to extraction during joint development. A number of methodological rules are proposed that make it possible to select indicators of the composition and properties of oils suitable for determining the contribution of individual strata to the mixed products. For the correct selection of reference oils of individual formations, it is recommended to take into account the geological block structure of the field and select wells from among those located as close as possible to wells with mixed products.
Dynamic paleotectonic analysis (DPA) was developed to study the direction (uplift/subsidence) and amplitude of movements affecting target horizons with potential for oil and gas traps. The primary objective of DPA is to identify zones of tectonic inversion – movements that trigger the formation of faults or zones of heightened mobility, which in turn facilitate the creation of hydrocarbon traps. Quantitatively assessing the dynamics of movement direction (uplift/subsidence) and amplitude allows for the identification of tectonic inversion zones within the sedimentary cover. In addition to traditional paleotectonic analysis, the DPA method enables a quantitative assessment of the geological evolution of the sedimentary cover. It helps to determine the geological epochs during which movement directions and amplitudes shifted and allows for the localization of tectonic inversion zones. Ultimately, this increases the probability of identifying areas likely to contain non-anticlinal hydrocarbon traps. In this work, the possibilities of supplementing qualitative analysis with a quantitative study algorithm are demonstrated using actual examples, allowing for the formalization of stages of paleotectonic evolution of the sedimentary cover and the numerical justification of the amplitudes and directions of tectonic movements.
