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Date submitted2024-05-30
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Date accepted2024-10-14
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Date published2024-11-12
Thermodynamic modelling as a basis for forecasting phase states of hydrocarbon fluids at great and super-great depths
The possibility of discovering oil and gas occurrences at great (more than 5 km) and super-great (more than 6 km) depths is considered in two aspects. The first one is the preservation conditions of large hydrocarbon accumulations forming at depths to 4 km and caused by different geological and tectonic processes occurring at great and super-great depths with partial oil-to-gas transformation. It was ascertained that among the factors controlling preservation of liquid and gaseous hydrocarbons are the temperature, pressure, subsidence rate (rate of temperature and pressure increase), time spent under ultrahigh thermobaric conditions, and initial composition of organic matter. The possibility of existence of liquid components of oil at great and super-great depths is characteristic of sedimentary basins of China, the Gulf of Mexico, the Santos and Campos basins on the Brazilian shelf, and in the Russian Federation it is most probable for the Caspian Depression, some submontane troughs and zones of intense accumulation of young sediments. Determination of critical temperatures and pressures of phase transitions and the onset of cracking is possible using the approach considered in the article, based on estimation of organic matter transformation degree, kinetic and thermobaric models taking into account the composition of hydrocarbon fluid. The second aspect is the estimation of composition of hydrocarbons associated with rocks forming at great depths or rocks transformed under conditions of critical temperatures and pressures. This aspect of considerable science intensity can hardly be considered as practically significant. The study focuses on the investigation of the possibilities of thermodynamic modelling and the use of alternative methods for studying the transformation degree of liquid formation fluid into components of the associated gas through the example of two areas with identified oil, condensate and gas accumulations.
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Date submitted2018-06-28
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Date accepted2018-09-15
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Date published2018-12-21
Causes of fluid entry absence when developing wells of small deposits (on the example of Khadum-Batalpashinsky horizon)
- Authors:
- R. A. Gasumov
A promising direction for the development of the oil and gas industry is the drilling of small hydrocarbon fields, which constitute two thirds of Russia's total hydrocarbon reserves. When choosing an effective method of development and assessing the potential of small fields in Eastern Ciscaucasia, which are characterized by complex mining and geological conditions with abnormally high reservoir pressures and temperatures, it is necessary to determine the optimal amount of oil production taking into account the flow of edge water under elastic water drive. The article discusses the reasons for the lack of inflows of reservoir fluids in wells during their development, which are due to complex unconventional fractured clay reservoirs in the lower Maykop deposit and the presence of loose rocks in the section of the reservoir. The results of studies of the influence of technological and geological factors on the poroperm properties of the Khadum-Batalpashinsky reservoir are described, zones of rock softening are revealed, the intervals with bottom water and their influence on the well development process are specified. It has been established that the state of the hydrodynamic system of the field depends on the introduction of the bottom and edge waters of the sedimentation basin of the East Stavropol Depression. Oil deposits in the Khadum and Batalpashinskaya suites initially work in an elastic and then in an elastic-water drive mode. The main reasons for the lack of inflows of formation fluids into wells are the low reservoir properties of clay fractured reservoir rocks; clogging of the fracture capacity of reservoir rocks at the drilling in as a result of penetration of drilling mud and its filtrate deep into the reservoir; inflow of formation water from an overlying aquifer with abnormally high formation pressure; the closure of cracks in the clay reservoir due to a sharp decrease in pressure caused by the lowering of the slotted filter into the well; secondary dissection of productive layers by perforation during repression on the formation in a liquid medium with the presence of a solid phase and high density.
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Date submitted2017-12-28
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Date accepted2018-03-03
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Date published2018-06-22
Special features of a structure of technical operations for peat excavation with stage dewatering
- Authors:
- E. A. Kremcheev
A method of development of a technology of peat extraction for intensifying of dewatering which involves drying of peat raw materials in thick layers with a layer-by-layer harvesting into large-sized roll with further delivery to the field storage unit of the enlarged sizes is presented in the paper. Throughout the year storage raw materials may be transported to the customer or to the shopfloor for further processing. Considering dimension and mass characteristics, a crumbed peat of various moisture capacity is a major type of products to be of high demand. On the basis of the results of scientific studies regarding gravity dewatering of peat and its drying in field environment, the ways of intensifying of field dewatering of peat for extraction at shallow-peat lands and fine-limit fields are proposed. The presented results of the experimental performance of a technology of peat drying in thick layers with a layer-by-layer harvesting indicate an increase of seasonal harvesting and a decrease of the influence of unfavorable meteorological factors on the stability of the extraction process. Performed investigations allowed to develop a structure of technical operations for peat excavation with the stage dewatering in spreading and intermediate storage units providing rational state of the extraction process regarding a complex of technical factors. A suggested scheme of a process area for a primary and secondary period of deposit exploitation by a technology of peat excavation is considered.
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Date submitted2008-10-23
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Date accepted2008-12-05
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Date published2009-12-11
Application of electrical prospecting in combination with seismic prospecting for the geological section prediction and search of hydrocarbon deposits
- Authors:
- V. A. Kuzin
- A. A. Korukhova
The possibility of application of electrical prospecting method SGN (sounding by field growing in the near-field zone) in combination with CDP seismic prospecting for sedimentary section investigations and hydrocarbon deposits prospecting is considered. The physical basis of the method application for hydrocarbon prospecting is the effect of higher resistance of seams, saturated by hydrocarbons. The effect is reflected in the curve of electromagnetic field growth ε(t). The procedures of field works, processing and interpretation of electrical prospecting data are presented.
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Date submitted1958-03-16
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Date accepted1958-05-23
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Date published1958-05-09
НОВЫЙ МЕТОД ОПРОБОВАНИЯ ПО ТИПАМ РАЗРЕЗОВ
- Authors:
- Unknown
Предлагаемый метод опробования основан на закономерной зависимости между строением рудных залежей по мощности и содержанием ценного минерала. Основным объектом исследования явилось месторождение, на котором наиболее крупные рудные залежи генетически и пространственно связаны с первично хорошо расслоенным комплексом пород. Основной причиной образования расслоенного комплекса пород и рудных залежей является кристаллизационная дифференциация, которая заключалась, по-видимому, в следующем: а) движении кристаллизующегося магматического расплава; б) гравитации; в) большом скоплении элементов, дающих легколетучие соединения; г) увеличении вязкости кристаллизующегося расплава; д) неравномерном (последовательном сверху — вниз) охлаждении интрузивного тела; е) двух периодах кристаллизации расплава: первом — медленной кристаллизации главным образом лейкократовых минералов, втором — более быстрой кристаллизации всех остальных минералов магматического происхождения.
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Date submitted1950-08-02
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Date accepted1950-10-05
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Date published1951-08-08
Some data clarifying the coefficient of variation
- Authors:
- N. V. Ivanov
The article sets the task of specifying the variation coefficient reflecting the distribution of a useful component in an ore deposit. The variation coefficient is a value characterizing the dispersion of the distribution of the material composition in the ore body of a particular deposit. As is known, attempts to use the variation coefficient to solve applied problems (for example, choosing the distances between samples and workings during sampling and exploration of deposits) were not very successful. The density of various workings and samples in this case significantly exceeded the accepted and justified practice. The unsuccessful use of the variation coefficient in solving the above problems is partly explained by the presence of a pattern in the spatial distribution of the material composition in the ore bodies of deposits, which is in conflict with the basic provisions of variation statistics. In addition, the determination of the value of the variation coefficient itself is inaccurate for two reasons: 1) incorrect use of factual material reflecting the nature of the mineral; 2) the influence of sampling error on the value of the coefficient of variation.