Perm Journal of Petroleum and Mining Engineering

One of the aspects of the formation of the hydrocarbon potential of the main oil and gas source rock (OGSR) of Upper Devonian-Tournaisian age in the context of the sedimentary cover of the Perm Krai was considered. The subject of study was the basic chemical and bituminological characteristics of dispersed organic matter (DOM) of source rocks. The sample of parameters collected to study the thickness contained more than 4300 definitions. The main goal of the study was to differentiate the dispersed rocks organic matter depending on the distribution of bitumen coefficient values and the enrichment degree of strata with organic carbon. According to the conditions of formation, the Upper Devonian-Tournaisian rock was characterized by the maximum development in this territory of favorable geochemical facies, under the conditions of which the DOM transformation into petroleum hydrocarbons occurs. Statistical analysis of the average values of chemical and bituminological parameters confirmed the syngenetic nature of the DOM to the containing rock with a high degree of transformation and enrichment in migratory bitumens, which allowed considering this strata to generate oil and gas and ensured the formation of the oil and gas content. Further, based on fundamental research, in particular the Uspensky-Vassoevich relationship, the differentiation of DOM of the Devonian-Tournaisian formation into syngenetic, mixed and epigenetic was for the first time quantitatively substantiated. By studying the sample using regression and discriminant analysis methods, it was shown that the identified types of DOM were statistically different in the ratio of the parameters Corg and β, which proved their relationship to bitumen of different types. For each identified type of DOM within the stratigraphic units of the main OGSR, different types of relationships between the studied parameters Corg and β were also statistically established. As a result of the research, the author established the individual percentage distribution of DOM types for each horizon of the Upper Devonian-Tournaisian oil and gas source rock and statistically proved their difference in the ratio of Corg and β, which characterized the individual intensity and direction of converting bitumen into micro-oil. It was established that in this sequence the Domanik horizon itself was characterized by the widest development of epigenetic bitumen.

The article describes the issue of determining the properties of rocks with different fluid saturation and the relationship between changes in these properties from the stage of oil field development. The mineral composition of the studied clayey samples of oil reservoir rocks was given. The process of changes in the strength and elastic properties of the rock due to different saturation with kerosene and water was described. The dependences of the ultimate strength under uniaxial compression, elastic modulus and Poisson's ratio for rocks of different fluid saturation were presented. The decrease in the strength and elastic modulus of rock samples with complete replacement of kerosene with water reached 15-20%, and in comparison with the results obtained for a sample in an air-dry state, the decrease in these same properties reached 30-40%. Based on the theoretical and practical studies the need to determine the strength and elastic properties of rocks depending on saturation in real field conditions became obvious. The results of filtration studies for clay rock samples were presented. It was established that a decrease in reservoir pressure contributed to an irreversible decrease in the permeability of the studied clayey rocks. It followed that the introduction of systems for maintaining reservoir pressure must be carried out as early as possible. An example of calculating relative permeability, pressure distribution in the reservoir at a constant flow rate was given, graphs of the distribution of the water/oil displacement front were constructed by year of field development with a plane-radial inflow into the well. The dependences of the elastic capacity coefficient and piezoelectric conductivity of the rock on fluid saturation were presented. The obtained results and the established dependencies are recommended to be used when predicting changes in the strength, elasticity and filtration-capacitive properties of pore-type clay rocks at various stages of oil field development, including for planning well treatment.

Oil production forecasting plays an important role in efficient oil field development. This helps to adjust the current field development system. Detailed and accurate forecasting of oil production levels is necessary to assess the economic and technological efficiency of oil field development. Forecasting production levels can be done in various ways. One of these may be the use of special software (tNavigator, etc.). The use of this software sometimes involves lengthy calculations, so to quickly predict production levels, it is possible to use other tools, such as machine learning. The use of machine learning and artificial intelligence in the oil and gas industry has become increasingly popular in recent years, as by using historical production data, it is possible to predict oil/liquid production levels. In addition, similar deposits with similar geological characteristics and exploitation history can be used for similar purposes. In addition to using machine learning and artificial intelligence as a forecasting tool, it is possible to use decline curve analysis. Given the importance of forecasting from a strategic planning perspective, a wide range of methods have been proposed to obtain accurate forecasts based on the nature of available data and computing power. This article provides a comprehensive analysis of the tools used for long-term oil production forecasting, including machine learning algorithms and decline curve analysis (DCA), in particular. This article presents the results of applying the long- and short-term memory model and its practical applicability using the example of its use on a candidate well.