Applying the combination of GIS tools with upgraded structural and morphological methods for studying neotectonics

Structural and geomorphological methods are often applied to the search for small oil-producing structures. Morphometric analysis of digital elevation models has proved to be the most informative one. Morphometric surfaces can be used to evaluate the direction and amplitude of vertical movements, to outline local and regional neotectonic structures and assess their petroleum saturation. This paper shows how to enhance the traditional morphometric analysis with GIS (geographic information systems) tools. A manifold increase in the efficiency of morphometric analysis takes it to a qualitatively new level. Setting specific parameters for some geoprocessing tools (for example, stream network tools) can be very important when studying local structures in small areas. In case of large territories, the output result is almost independent of the calculation errors. The improved technique proposed in this paper was tested on a large territory located in the Volga region. As a result, high-order morphometric surfaces were obtained, which was not possible before. In addition, a statistically significant relationship was discovered between morphometric surfaces and distribution of oil deposits, which can be considered a reliable prospecting indicator in the Volga-Ural petroleum province. Keywords: neotectonics; structural and morphological methods; geoinformation systems; hydrocarbon potential assessment.

The research and development of technical and technological solutions for the operation of oil wells with increased gas content

In the practice of oil production, there are oil deposits with high values of gas content (gas factor), from tens to hundreds of cubic meters of gas per one ton of oil produced. Gas dissolved in oil and coming from the reservoir into the well along with the liquid phase (oil, water), under certain thermodynamic conditions, is capable of forming hydrates, which complicate the operation of downhole pumping equipment, reduce the efficiency of pumps and well flow rate. The formation of gas hydrate plugs in the well requires the total overhaul, which leads to an increase in non-productive time, financial costs and an increase in lost profits on lost oil. Considered in the article technologies and devices that prevent the formation of gas hydrates in marginal wells with a high gas content in oil have shown their unreliability and low efficiency. The authors propose for the consideration a new effective technology for the operation of such wells, which makes it possible to avoid the formation of hydrates. Keywords: well; gas content; hydrates; production; oil; valve; coupling; pump.

Tectonic aspects of super-viscous oil deposits formation and placement within the Volga-Ural anteclise

The article discusses the tectonics and developmental features of the Volga-Ural anteclise during the Baikalian, Caledonian, Hercynian and Alpine tectogenesis cycles. In this paper, particular attention is paid to stages and directional development during the evolution of geological structures. The main factors of the formation and destruction of Permian viscous oil and natural bitumen reservoirs are presented in the provisions of oil ontogenesis. It was noted the cyclical nature of these phenomena. Keywords: Volga-Ural anteclise; super-viscous oil; tectonic; reservoir; oil.

METASOMATIC CHANGES IN ROCKS OF SEDIMENTARY COMPLEXES IN THE CARPATHIAN OIL AND GAS PROVINCE AS AN INDICATOR OF CARBOHYDRATE MIGRATION

A field and laboratory investigation of sedimentary rocks in Carpathian oil and gas province was curried out. The theoretical and practical aspects of the peculiarities of the development of metasomatic process during the migration of fluids at the postsedimentation stage of rock formation were investigated. Based on detailed field researches, a consistent pattern of mineral aggregates’ and their crystalloid individuals developing was defined. The arguments for developing a new geochemical model of oil deposits indication in Carpathian oil and gas province were provided.

Study of synthesis of hydrogen and hydrocarbons by mechanochemical activation of the surface of mineral rocks

In the light of the eternal discussion regarding the sources of hydrocarbons for the initial oil and gas-forming substance, it is possible to recognize the legitimacy of both organic matter, which is confirmed by the biogenic theory of the origin of oil, and deep gases, declared by supporters of the theory of the inorganic concept, referring to the extraordinary richness of hydrocarbons in the mantle. But, the catagenic stage, the process of obtaining oil from the initial substance, in which the primary carbonaceous substance (often under such hypothetical concepts as “micron-oil”, “fluids”) passes into hydrocarbons in the form of oil deposits, causes no less scientific interest and also insufficiently studied. The author sees it as fair to attempt to put emphasis on predominantly geodynamic conditions, tectonic stresses, physico-chemical and thermobaric conditions, the generation of hydrocarbons, on the basis of the synthesis of hydrocarbons in any geological period. The article proposes the author’s chemical model describing the low-temperature polycondensation synthesis of hydrocarbons from water and carbon dioxide in the process of mechanical reactions on the surface of a rock model.

Summer sea-ice variability on the Antarctic margin during the last glacial period reconstructed from snow petrel (Pagodroma nivea) stomach-oil deposits

Antarctic sea ice is a critical component of the climate system, affecting a range of physical and biogeochemical feedbacks, and supporting unique ecosystems. During the last glacial stage, Antarctic sea ice was more extensive than today, but uncertainties in geological (marine sediments), glaciological (ice core), and climate model reconstructions of past sea-ice extent continue to limit our understanding of its role in the Earth system. Here, we present a novel archive of past sea-ice environments from regurgitated stomach oils of snow petrels (Pagodroma nivea), preserved at nesting sites in Dronning Maud Land, Antarctica. We show that by combining information from fatty acid distributions and their stable carbon isotope ratios with measurements of bulk carbon and nitrogen stable isotopes and trace metal data, it is possible to reconstruct changing snow petrel diet within Marine Isotope Stage 2 (ca. 22.6–28.8 cal. kyr BP). We show that, as today, a mixed diet of krill and fish characterises much of the record. However, between 25.7–26.8 cal. kyr BP signals of krill almost disappear. By linking dietary signals in the stomach-oil deposits to modern feeding habits and foraging ranges, we infer the use by snow petrels of open water habitats (‘polynyas’) in the sea ice during our interval of study. The periods when consumption of krill was reduced are interpreted to correspond to the opening of polynyas over the continental shelf, which became the preferred foraging habitat. Our results challenge hypotheses that the development of extensive, thick, multi-year sea-ice close to the continent was a key driver of positive sea ice-climate feedbacks during glacial stages, and highlight the potential of stomach-oil deposits as a palaeo-environmental archive of Southern Ocean conditions.

Features of the geological structure, tectonic development and oil and gas potential of the Chezhen depression (Bohai bay basin)

Background. In terms of oil and gas, the territory of the Chezhen depression has been studied insufficiently compared to the neighbouring same-range depressions. These depressions complicate the first-order Jiyang depression, geographically coinciding with the largest Shengli hydrocarbon field. In recent years, much geological and geophysical information about the oil geologyof the Chezhen depression has been accumulated, which allows its prospecting oil and gas potential to be assessed.Aim. To reveal regular features of the geological structure and location of oil deposits in the Chezhen depression in order to support the prospecting and exploration work within the Chezhen block of the Shengli field.Materials and methods. A comprehensive analysis of literature data and collected materials was conducted. A historical and geodynamic study of the evolution of the studied area according to literature data was carried out, along with an analysis of the most recent geological and geophysical information and exploration data based on the materials of the “Shengli AKOO Sinopek” oil company. The analysis was based on the data from 52 drilling wells and the results of seismic surveys performed in the central part of the Chezhen depression.Results. Specific features of the block geological structure of the area under study were established, which formed under the repeated influence of large-scale horizontal tectonic movements occurring at different periods of geological history. The role of the most recent fault system in the modern spatial distribution of oil deposits was determined.Conclusions. Our studies demonstrate a great prospecting potential of the Chezhen depression territory, where the discovery of new industrial oil deposits can be expected.