Vol 20, No 3 (2020)
- Year: 2020
- Articles: 9
- URL: https://ered.pstu.ru/index.php/geo/issue/view/119
Abstract
The results of an analytical generalization of laboratory research data of a petrophysical parameters complex of reservoir rocks - potential hydrocarbon reservoirs are presented. The object of research was the well-known horizons of the Meso-Cenozoic sedimentary basin productive strata. The studied territory includes actively and long-developed oil and gas onshore and deep-sea fields of Azerbaijan. More than a century-old history of these natural hydrocarbon accumulations development has shown that the main oil and gas deposits are associated with the South Caspian and Kurinsky depressions, which were subjected to intensive immersion during the Meso-Cenozoic time. Despite the fact that many fields of these depressions have been exploited for a long time, industrial prospects are quite high, especially in deep-seated parts. At the same time, the problems associated with the oil and gas extraction from them have not yet been completely resolved. Currently, the region is intensively developing subsoil resources at depths of more than 4-4.5 km, since at small and moderate depths most of the oil and gas deposits have already been explored (even in hard-to-reach areas). As it is known, in the oil industry, wells with a depth of more than 4 km are called deep, and more than 6 km are called super-deep. Moreover, in addition to purely technical difficulties, the drilling of such wells is fraught with serious economic problems. So, the cost of developing deep, and even more super-deep wells is quite high and varies from 2-3 to 9-12 million dollars. This fact necessitates an increase in work efficiency, which requires a high degree of geological justification of the field prospects and the well location choice.
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Abstract
The creation of a Permo-Carboniferous reservoir conceptual model of the Usinskoye field is considered. To achieve this goal, the tasks of developing a specialized tabular format for describing thin sections of the carbonate deposits core are being solved, the formation of a database based on the developed format for subsequent analysis. The object of the study was the Permo-Carboniferous deposit of the Usinskoye field located in the Komi Republic. According to the developed format, a unique database was formed on 1710 described thin sections from 12 wells. The classification of carbonate rocks by R.Kh. Dunham with the additions of Embry and Cloven (according to the predominance of structural components in limestone, the type of cementing substance, as well as their relationship in the rock). Based on the rock material composition and the structural parameter, nine lithotypes of rocks have been identified: madstone, wackstone, packstone, grainstone, boundstone, floutstone, orestone, crystalline carbonate (dolomite), clayey-carbonate-siliceous rock. According to the results of certain lithological types of rocks and seismic data in the section of the Middle Carboniferous-Lower Permian deposits, three main facies zones have been identified: carbonate shelf (zone of the inner ramp); organogenic structure (middle ramp zone); shallow shelf plain (middle ramp zone, partly outer ramp zone). Additionally, the facies of the moderate-deep-water shelf plain (the outer ramp zone) is distinguished. As a result of the research carried out, two profiles of the Carboniferous-Lower Permian deposits of the Usinskoye field were built along two lines of wells. The presented sections confirm the constructed conceptual model. According to the core study in the eastern part of the deposit, a zone of organogenic structures is well distinguished, the formation of which occurred mainly in the Middle-Late Carboniferous and Early Permian time. In the northwestern part of the field, an internal ramp with carbonate bar facies is assumed. As a result of the work carried out, a conceptual model of the Permo-Carboniferous deposit of the Usinskoye field was built, which can be used for the subsequent construction of more reliable three-dimensional facies models, industrial calculation of reserves and design of field development.
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Abstract
The hydrodynamic model (HDM) is a tool for designing the development of oil fields, calculating the efficiency of geological and technical measures (GTM) and performing predictive calculations of development indicators for a long period. A method had been developed for correcting the values of the permeability cube during the adaptation of the hydrodynamic model, taking into account the relationship between the petrophysical properties of rocks according to the core study data. The technique was applied to the example of a deposit of the Bobrikovsky formation (terrigenous reservoir) of one of the deposits of the Solikamskaya depression. The work carried out a statistical analysis of the reservoir properties of the Bobrikovsky reservoir according to the results of the interpretation of well logging and according to the hydrodynamic model; the differences between the initial permeability obtained after rescaling of the geological model and the permeability after HDM adaptation were considered. As a result of the analysis, discrepancies in the statistical characteristics of the permeability values according to the interpretation of well logging and in the hydrodynamic model were revealed, as well as significant differences in the cubes of the adapted and initial permeability. It was found that in the model setting process, the initial permeability was significantly modified by the "manual" adaptation method. Revealing and correction of permeability extreme values were performed on the basis of the petrophysical dependence KPR = f ( KP ) from the core, taking into account the ranges of variation of the porosity and permeability coefficients. Using a modified permeability cube, calculations were performed to reproduce the development history of the object. Based on the results of the calculations, convergence with the actual data was achieved, the deviations meet the requirements for the accuracy of the model adjustment. Thus, this method of correcting the permeability cube after "manual" adaptation of the model will allow to avoid significant overestimations or underestimations of permeability in the cells of the hydrodynamic model.
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Abstract
The relevance of increasing the stability of the wellbore through the development and use of rational compositions of drilling fluids for the construction of wells in fractured mudstones is described. In the process of well construction, various complications arise associated with the instability of the rocks composing the wellbore walls, which entails a decrease in the rate of penetration, an increase in the construction cost, and in some cases leads to the well abandonment. Often, complications are appeared in the intervals of clay rocks drilling, which make up 70 % of the fields sections. When using water-based drilling mud, swelling of clay rocks due to interaction with the dispersion medium of the mud has a negative impact on the drilling process and can significantly increase the cost of well construction. The accumulation of collapsed rock in the wellbore makes it difficult to flush the well, contributes to the seating of the drilling tool and can cause sticking. An analysis of drilling problems in fractured mudstones is presented, mechanisms that affect the stability of an open wellbore in fractured mudstones are shown. To increase the stability of mudstones composing the wellbore walls, the use of potassium chloride is recommended. The results were confirmed by the data of experimental studies carried out according to the Cenevert method, as well as testing for fracture wedging. When the mudstone sample was placed in a potassium chloride (KCl) solution, slight expansion and propagation of cracks along the entire length of the sample was observed, which was a positive result. To increase the wellbore stability, ways of further study are proposed: improving the quality of the drilling mud by introducing complex inhibiting additives, such as, for example, salt solutions in combination with high molecular weight polymer compositions.
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Abstract
The waterflooding efficiency in the complex-structured carbonate reservoir of the Tournaisian-Famennian object of the Magovskoye field is investigated. This object is characterized by difficult geological conditions, which directly affects the efficiency of its development. In the course of the work, the following were analyzed: history and current state of the object development, dynamics of the production and injection wells, object energy state, reservoir pressure dynamics in the wells, geological features of the reservoir and the lithological-facial structure. A relationship was established between wells operation and lithofacial heterogeneity of the formation. An intra-contour waterflooding system was organized at the object in combination with a contour waterflooding system, which was characterized by low efficiency. For a number of wells located in the edge parts, there was a reduced reservoir pressure, these areas were characterized by deteriorated reservoir properties. There was also a distinction between the upper and lower parts of the section: wells that had penetrated the lower part of the section were characterized by positive dynamics of fluid production and a positive energy state, which in turn was associated with the influence of the boundary area; the wells that had penetrated the upper part of the section were characterized by poorer porosity and permeability properties, higher segmentation and the absence of the influence of the contour area. Wells located in zones with low reservoir pressure had been analyzed, the reasons for the low energy state had been identified, and proposals for research were given. Also geological and technical measures carried out at the object under consideration and at the facilities of analogous fields in the corresponding geological and field conditions were considered, measures with the greatest technological effect were identified. As a result of the research, geological and technical measures were proposed, taking into account the structural features of the lithological-facial zones, the nature of the relationship between production and injection wells, which would increase the efficiency of the waterflooding system and, in general, would have a positive effect on the efficiency of the object development.
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Abstract
In the current macroeconomic conditions, it is very important at the early design stages to assess the efficiency and risks of developing an asset. At present, design in the oil industry is impossible without the implementation of integrated design technologies, which provide for the management of all technical information about the facility at the initial stage of work throughout the entire cycle of its further operation. In a short time, it is necessary to make investment decisions based on incomplete and disparate initial data. The tasks are solved through the use of conceptual design tools. This work is devoted to the assessment and analysis of existing approaches to the conceptual design of a collection system and field development. The methods and tools of conceptual engineering by such companies as Ingenix Group, Gazpromneft STC LLC, Gazpromneft-Development LLC, RN-UfaNIPIneft LLC, JSC TomskNIPIneft and PermNIPIneft branch of LUKOIL-Engineering LLC in Perm were considered. The application of conceptual design tools at priority facilities for the Branch, such as the development of the Komandishorskaya group of fields and a feasibility study for a development strategy for the Varandey-Adz'vinsky asset was presented. For both projects, multidisciplinary teams were created, an operational recalculation of reserves was carried out, a multivariate study of schemes for gathering and construction systems was carried out taking into account a probabilistic approach, economic efficiency was assessed and optimal options were proposed. Based on the analysis, the main conceptual design tools for the development of a system for the arrangement of new assets were identified, and the ways of further methods implementation development in the PermNIPIneft branch of LUKOIL-Engineering LLC in Perm were outlined.
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Abstract
The studies results of a quantitative assessment of gas content and gas-dynamic characteristics of clay-carbonate and salt packs located along the geological section of the Starobinskoye potassium salt deposit between III and IV potassium horizons are presented. Mine experimental studies of gas content and gas-dynamic characteristics of clay-carbonate and salt packs were carried out in slopes opening up the IV potash horizon in the field mine of the 2nd mining department of JSC "Belaruskali". The methodology of mine experimental studies provided for a quantitative assessment of the following indicators: gas content for free gases, initial gas release rate and pressure of free gases in rocks of the 12th, 10th, 8th clay-carbonate packs, as well as the 11th and 9th salt packs. Based on the results of mine experimental studies, a quantitative assessment of the gas content and gas-dynamic characteristics of rocks of the 12th, 10th, 8th clay-carbonate and 11, 9th salt packs was given. The most gas-bearing layers of clay-carbonate and salt units, as well as the changes regularities in gas content and rock gas-dynamic characteristics along the geological section between III and IV potash horizons were established.
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Abstract
The increase in production capacity and the development of ventilation networks in underground mines pose a challenge for mining enterprises to increase the capacity of the mining and ventilation equipment used. Most mining equipment for loading and transporting rock in ore deposits is based on equipment with diesel internal combustion engines. Insufficient ventilation or inadequate calculation of the air amount required to dilute the main components of exhaust gases from internal combustion engines, such as carbon monoxide and nitrogen oxides, can lead to poisoning or even death of mining workers. However, at most modern enterprises, ventilation equipment operates within the limits of technical capabilities - without the likelihood of increasing the technical reserve. This fact, in turn, directly affects the safety of mining operations. The article presents methods and dependencies for calculating the required amount of air for the working areas of machines equipped with internal combustion engines, underground mines during their design and operation. Analysis of the regulatory literature showed that currently there was no required rate of air consumption per power unit of an internal combustion engine. Therefore, an approach was proposed that meets modern industrial safety requirements, based on actual emissions of harmful components, operating parameters of internal combustion engines and emission standards guaranteed by the manufacturer by confirming the engine's compliance with the environmental class. The proposed methods would improve the safety at workplaces when operating equipment with internal combustion engines in underground mines, as well as increase the efficiency of designing new blocks, horizons and mines by eliminating an unreasonable reserve when selecting mining and ventilation equipment.
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Abstract
The problems associated with the use of mining machines with diesel engines, the exhaust gases of which have a harmful effect on human health and the environment, are analyzed. The mining industry operates a huge number of diesel-powered equipment: mining trucks, excavators, drilling rigs and other mining machines. Engine exhaust gases contain toxic elements that have a significant impact on the health of personnel and the environment. The gas contamination of the working atmosphere entails the need to stop the quarry, and the deterioration of visibility on the route leads to a partial or complete shutdown of the equipment. Today, environmental requirements for a car engine are of top priority. The problem of atmospheric pollution by harmful substances contained in the exhaust of diesel engines is becoming global. Its solution requires the joint efforts of many countries. International conventions and the adoption of relevant standards serve as a tool for convergence in this area. Most countries in Europe, Asia and America are guided by similar standards for the content of harmful substances in exhaust gases. In this regard, the European Union is a kind of authority: it most often updates these indicators and introduces strict legal regulation. Other countries are following this trend and are also updating emission standards. European countries paid attention to this issue earlier than others. Today, environmental requirements for a car engine are of top priority. Research in this area is associated with such directions as increasing the performance of mining machinery engines, reducing labor costs for their maintenance and repair, increasing fuel efficiency, significantly improving environmental performance.
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