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Date submitted2023-12-07
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Date accepted2024-11-07
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Date published2025-04-25
Determination of the tangential component of cutting resistance during frozen sedimentary rock cutting using blocked, deeply blocked and cell cutting methods
Due to the insufficient accuracy of existing studies of frozen sedimentary rock cutting process for practical calculations, the article solves the problem of determining the tangential component cutting resistance for blocked, deep blocked and cell cutting, which are currently the most commonly used methods in earthmoving equipment. The cutting tool and rock mass force interaction is considered from the point of view of the emerging stresses, which act on the separated chip element. The analytical dependences for determining the tangential component of cutting resistance were obtained. The numerical explanation of the choice of cell cutting in relation to blocked and deeply blocked cutting is given. For all three methods of cutting, under equal geometrical parameters of the cutting tool and the physical and mechanical properties of the frozen rock, the numerical value of the tangential component of cutting resistance is obtained. The comparison of the cutting resistance estimated values has shown that cell cutting requires relatively less energy and is preferred during the process of frozen sedimentary rock excavation. During field and laboratory investigations with the use of a multi-purpose cutting stand, a sufficient convergence of the analytical statements with the physics of frozen sedimentary rock cutting process was established. The results of the research allow a more reasonable approach to the adjustment of existing methods for determining the required tractive force and power for the drive of an excavation machine, and, therefore, to the actual efficiency and profitability of work.
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Date submitted2022-09-30
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Date accepted2024-11-07
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Date published2025-02-25
Carbon dioxide corrosion inhibitors: current state of research and development
Among the methods of corrosion control in the oil and gas production industry the leading place belongs to inhibitor protection, since there is no need for technological and technical changes in the existing equipment. The combination of high variability of inhibitor composition with changing conditions of its application and low capital investments makes it an indispensable reagent at oil and gas fields. The main classes of compounds used as active bases of carbonic acid corrosion inhibitors for the protection of oil and gas equipment are described. Classical organic active bases containing heteroatoms (oxygen, sulfur, nitrogen) are examined. Special attention was paid to alkylimidazolines and other nitrogen-containing compounds as the most frequently used as active bases of carbonic acid corrosion inhibitors in Russia and abroad. A wide range of possibilities to achieve the desired properties of corrosion inhibitors by varying the substitutes has been demonstrated. Nowadays, in addition to the traditional requirements for corrosion inhibitors, their safety for the environment is equally important. The information on prospective research and development aimed at improving the environmental characteristics of the reagents used is given. Plant extracts, synthetic and biological polymers involved in traditional corrosion inhibitors or used as new independent compounds are considered. It is shown that the effectiveness of corrosion inhibitors significantly depends on the pH of the medium, temperature, partial pressure of СО2, flow rate, and other factors.
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Date submitted2022-10-29
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Date accepted2023-02-13
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Date published2023-04-25
The use of unmanned aerial photography for interpreting the technogenic transformation of the natural environment during the oilfield operation
The traditional approach to monitoring observations of the technogenic processes development in oilfields, which consists in determining the concentration of marker pollutants in various natural environments, does not provide the necessary completeness of information and the efficiency of its receipt. The paper considers an example of expanding the range of observations due to unmanned aerial photography and a number of other methods. Interpretation signs (for panchromatic survey) were determined that register such consequences of technogenic transformation of the natural environment as mechanogenesis, bitumization, and halogenesis. Technogenic mechanogenesis is understood as a physical violation of the integrity of ecosystems, the movement of soils and grounds. Bitumization is expressed in the migration of petroleum hydrocarbons through soils, ground, surface, subsurface, and underground waters, and their destruction. Salt migration in these media is defined as halogenesis. The most reliable indicators are linearly elongated areas of dead forests, dark red spots in drying microdepressions and reservoirs. It was found out that the oilfield impact on the raised bog leads to anthropogenic eutrophication, the introduction of plant species, uncharacteristic coenotic groups, the replacement of subshrubs with grasses, and morphometric changes in forest pine. In the peat deposits of the disturbed area, an unusual interlayer of whitish, undecomposed moss was recorded. The moment of the beginning of a pronounced technogenic transformation was registered in the course of work with the archive of multispectral space images. Continuous remote sensing with the help of unmanned aerial photography and interpretation by sedimentological, geobotanical methods significantly expand the possibilities of studying the technogenic transformation of the natural environment. To ensure environmental safety, it is advisable to develop remote methods and technologies to include them in the environmental monitoring system.
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Date submitted2022-05-12
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Date accepted2022-09-15
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Date published2022-12-29
Problem solution analysis on finding the velocity distribution for laminar flow of a non-linear viscous flushing fluid in the annular space of a well
- Authors:
- Vasiliy I. Nikitin
Modern drilling fluids are non-linear viscous media with an initial shear stress. In classical scientific works on hydromechanical modeling of drilling fluids motion in pipes and annular channels the Shvedov – Bingham approximation and Ostwald – de Waale power-law model were used, which did not fully account for behavior of technological fluids in a wide range of shear rates. This article presents a numerical solution for a mathematical model of drilling fluid motion of the three-parameter Herschel – Bulkley rheological model in the annular space of the well. The Herschel – Bulkley model in the rheological equation takes into account the presence of initial shear stress and a tendency for viscosity to change with shear rate, which distinguishes it from the Ostwald – de Waale and Shvedov – Bingham models. The target function in solving the equation of motion is the velocity distribution in the radial direction of the upward flow of the flushing fluid. The analysis of obtained solution is based on the theory of velocity profile influence on quality of cuttings removal during wellbore cleaning. Due to peculiarities of mathematical statement of the task, which supposes necessity of differential equation of motion solution, Wolfram Mathematica computational software has been used as a calculation tool. The analysis of numerical solution allowed to draw conclusions about the possibility of its application in evaluation of velocity profile when drilling fluid moves in annular space of the well. The possibility for application of modified excess coefficient as a relative quantitative parameter for evaluation of velocity profile uniformity was substantiated.
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Date submitted2022-03-24
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Date accepted2022-07-21
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Date published2022-12-29
A probabilistic study on hole cleaning optimization
- Authors:
- Seyyed Shahab Tabatabaee Moradi
Hole cleaning is considered as one of the most important drilling fluid functions. An efficient hole cleaning ensures a reliable well drilling practice with minimum troublesome problems. In this study, two main steps of hole cleaning, i.e., cuttings removal from under the bit and cuttings transport to the surface are discussed based on the drilling data of a shale formation. The traditional models for optimization of each step are presented. As the models require variety of input data, which are usually subjected to some extent of errors and uncertainties, the output of the model is also an uncertain parameter. Using Monte Carlo simulation, a simple probabilistic study was conducted to quantify the certainty level of the obtained results. Based on the result of this study, it is shown that for the proposed well, a good hole cleaning is expected. However, a more reliable decision for further hole cleaning optimization should be made considering the results of uncertainty analysis.
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Date submitted2022-11-06
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Date accepted2022-11-29
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Date published2022-12-29
Technological sovereignty of the Russian Federation fuel and energy complex
- Authors:
- Oleg V. Zhdaneev
The review to achieve technological sovereignty of the Russian fuel and energy complex (FEC) in the ongoing geopolitical situation is presented in the article. The main scope has been to identify the key technology development priorities, restrictions and internal resources to overcome these utilizing the developed by the author the innovative methodology that consists of novel approaches to calculate level of local content, digitalization, business continuity andinteractions with military-industrial complex. Some organizational changes have been proposed to intensify the development of hi-tech products for the FEC and related industries, including establishment of the state committee for science and technology and the project office of lead engineers for the critical missing technologies. Two successful examples to utilize the described in the paper methodology is presented: the first domestic hydraulic fracturing fleet and polycrystalline diamond compact cutter bit inserts.
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Date submitted2021-12-19
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Date accepted2022-07-21
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Date published2022-11-10
Increasing the content of coarse fractions in the mined coal mass by a combine using paired cuts
The main volume of coal is mined underground using shearers. In modern shearers, auger actuators are mainly used, which are distinguished by the simplicity of design, manufacturability and reliability. However, in the process of separating coal from mass by cutting, the yield of fine grades is 40-50 % of the total production volume. Therefore, the search and development of technical solutions that provide an increase in the yield of large fractions in the process of coal mining with auger shearers is an urgent task. Traditionally, this problem is solved by increasing the thickness of the slices, which is achieved by installing cutters with a larger radial reach and increasing the shearer feed rate. An unconventional way to increase the cross section of slices by forming energy-efficient paired and group slices with mutual superposition of stress fields in the mass from the action of neighboring cutters is considered. The results of modeling the process of cutting coal confirm that an increase in the efficiency of destruction of the rock mass by the cutters of the auger executive bodies of the shearer can be achieved by a complex technical solution, including the formation of paired cuts and combined stress zones in the rock mass. As a result, the output of large fragments when cutting with paired cutters increases by 1.3-1.8 times compared with cutting with a single cutter.
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Date submitted2021-09-22
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Date accepted2021-11-30
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Date published2021-12-27
Possibilities for creating Russian high-tech bottomhole assembly
Development of high-tech well electronic measuring systems is aimed at creating modern equipment: telemetry, well geophysical measurement equipment, the architecture of which is divided into basic (with measurement channels for gamma logging and inductive resistance) and advanced (with radioactive, acoustic, magnetic resonance and thermobarometric measurement channels, including azimuthal methods of investigation). Over-the-bit measurement modules, rotary steerable systems are being developed and channels for transmitting data to the surface are being improved. Vice versa, specialized surface equipment with highly integrated software is being created. Different measurement modules are manufactured by different companies, which creates uncertainties in the possibility of interfacing the manufacturers' measurement modules into a single well measurement system. The article presents an analysis of the readiness of Russian oil service companies to produce well and surface equipment for drilling Russian directional oil and gas wells, meeting modern requirements for accuracy, lifetime and operating conditions. The possibility of creating a fully Russian well high-tech equipment and the required resources, risks and measures to mitigate them when creating a modern well measurement system are considered.
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Date submitted2020-05-13
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Date accepted2021-05-21
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Date published2021-09-20
Increasing the efficiency of technological preparation for the production of the manufacture components equipment for the mineral resource complex
An increase of components production for the equipment intended for oil and gas production is a key factor for analyzing existing technological processes and searching for new technological solutions to improve the efficiency of the production process and the quality of components. The article presents a simulation model designed to determine the rational technological processing parameters for the production of the “Centralizer shell” part. The basis for optimizing the working cycle of a production line is synchronization based on the principle of proportionality, which involves equalizing the duration of all technological operations with the rhythm of the production line. Synchronization of technological operations on the production line is carried out by choosing rational cutting parameters for each technological transition (cutting speed, feedrate, number of working passes). The “Centralizer shell” part is made of titanium alloy VT16, which has high strength, corrosion resistance and ductility. For the part under consideration, the permissible values of the cutting parameters were determined based on the calculation of the total processing error, as well as the frequency of replacement of the worn cutting tool. The simulation model described in the article made it possible to increase the efficiency of the production process due to the synchronization of technological operations and the search for rational technological parameters, as well as to improve the manufacturing quality of the “Centralizer shell” part by analyzing the processing error at various parameters of the technological process.
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Date submitted2020-07-04
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Date accepted2021-03-29
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Date published2021-09-20
Transition between relieved and unrelieved modes when cutting rocks with conical picks
In the modern theory of rock cutting in production conditions, it is customary to distinguish two large classes of achievable cutting modes – relieved and unrelieved. The kinematics of rock-breaking machines in most cases determines the operation of the cutting tool in both modes in one cycle of the cutting tool. The currently available calculation methods have been developed for a stable, usually unrelieved cutting mode. In this article, the task is set to determine the conditions for the transition between cutting modes and the modernization of the calculation method for determining the forces on the cutting tool. The problem is solved by applying methods of algebraic analysis based on the search for the extremum of the force function on the cutter, depending on the ratio of the real cut spacing to the optimal spacing for the current chip thickness. As a result of solving the problem, an expression is obtained for determining the chip thickness, for which, at the specified parameters, the transition between the relieved and unrelieved cutting modes is provided. The obtained result made it possible to improve the method of calculating the forces on the cutting tool in the areas of the cutter movement with relieved cutting.
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Date submitted2019-11-04
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Date accepted2020-01-12
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Date published2020-10-08
PDC cutter pressure on plastic-brittle rock in the process of its destruction
- Authors:
- Oleg B. Trushkin
- Hamzja I. Akchurin
Presently, there are no methods for calculating the parameters of the drilling practices with rock-cutting tools equipped with polycrystalline diamond composite (PDC cutters). To create such a method requires the studying their work. The article presents the results of bench studies of the PDC cutters in the process of a rock sample breakdown when reproducing the actual layout of the cutters on the working surface of the bit. An important parameter of PDC cutters operation, which is necessary for the bit load analysis, is the pressure of the cutters on the rock during its breakdown. The total pressure of a cutter on the rock can be broken into two mutually perpendicular components: the forcing pressure and the cutting pressure. It is proposed to evaluate the PDC cutters loading at breakage of rocks of different hardness using relative values of forcing and cutting pressures, which are calculated relative to the yield strength of the rock by the die. It is established that the variability of the average relative pressures of forcing and cutting is significantly influenced by drifting per bit turnover and the radius of the cutter on the bit. The dependences of the maximum relative pressures of PDC cutters at the plastic-brittle rock breakdown on the drifting per bit turnover and the radius of the cutter location on the bit are obtained. It has been established that when drifting up to 0.4 mm per turn, the main mechanism of breakdown is cutting, and with the increase of the breakdown depth, the process of forcing becomes decisive.
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Date submitted2019-10-17
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Date accepted2020-01-24
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Date published2020-04-24
Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)
The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta 2 O 5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.
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Date submitted2019-07-10
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Date accepted2019-08-30
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Date published2019-12-24
Methodology for calculating technical efficiency of power sections in small-sized screw downhole motors for the «Perfobur» system
With an increase in the share of old and low-yield wells and for the efficient exploitation of fields, it is necessary to include low-capacity formations into production. There are many wells where sidetracking and hydraulic fracturing are difficult due to the close proximity of the gas cap and underlying water caused by geological and technological reasons, and the use of existing secondary drilling-in technologies is not effective due to the extensive colmatated zone or annular circulation. Relevance of radial drilling technologies is growing, which allows drilling-in of the formation with a network of extended channels to establish high-quality hydraulic communication between the formation and the well without affecting the permeability of the formation. In contrast to radial drilling technologies using hydraulic washing, technical system (TS) «Perfobur» uses small-sized screw downhole motors (SDM) and rock cutting tools for channel construction. For efficient milling of production casing and destruction of rock, the hydraulic downhole motor must have high torque, and for the possibility of drilling with a high rate of angle gain, it must have short power section. Existing Russian and foreign SDM have limited number of standard sizes and do not meet the requirements specified for the development of the downhole module of TS «Perfobur». The paper discusses the development of universal small-sized sectional screw downhole motors for milling casing strings and drilling a network of branched channels of super-small diameter and radius of curvature as a part of the TS «Perfobur». Methodology proposed in the article for selecting optimal configuration of the SDM power sections allows constructing small-sized sectional downhole motor that meets the technical requirements and has improved characteristics compared to standard SDM.
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Date submitted2019-07-23
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Date accepted2019-09-19
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Date published2019-12-24
Estimation of abrasiveness impact on the parameters of rock-cutting equipment
Development of equipment, which provides access to underground mineral deposits and their extraction, requires the use of all the accumulated experience and advanced scientific research in the area of mechanical rock cutting. The most important issues of using mechanical rock cutting tools are their wearability and consumption, which have an impact on technical and economic indicators of project efficiency. The paper describes Russian and foreign practices of estimating tool wear resistance, expressions to determine critical cutting speed, methods to evaluate tool consumption. It is demonstrated that wearability of mechanical tools and associated effects are to a large extent defined by rock abrasiveness. It is highlighted that in Russia the index is calculated using Baron-Kuznetsov method, which is briefly described in the paper. In many countries with a highly-developed mining industry, rock abrasiveness is estimated with a Cerchar Abrasiveness Index (CAI), recommended by the International Society for Rock Mechanics. Its description is also presented in the paper.
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Date submitted2019-07-06
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Date accepted2019-08-25
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Date published2019-12-24
Improving the efficiency of technological preparation of single and small batch production based on simulation modeling
Technological preparation of production is an integral stage of the production process, which is characterized by high complexity, which is largely felt in the conditions of single and small-scale types of production. The effectiveness of technological preparation of production is increased through automation with the use of simulation modeling. The objective of the study is to develop a simulation model that allows you to determine a rational version of the process for processing a batch of parts. The simulation model described in the article allows to analyze the production schedule of the enterprise, build processing routes, evaluate options for using various types of workpieces and technological equipment, determine the acceptable values of cutting conditions, and choose a rational variant of the technological process of processing a batch of parts. The developed simulation model is based on the principles of modular technologies, the part is considered as a combination of individual elementary surfaces. Each elementary surface contains information about the technological processing route, technological equipment and the type of technological equipment used in its manufacture, cutting conditions and the size of the allowance for each processing stage. The rational choice of the technological process is selected on the basis of multicriteria analysis according to three criteria: the value of variable costs, the production time of a batch of parts and the value of the processing error. The analysis of these criteria is made and the parameters that have the greatest impact on their value are determined. The developed classification of surface elements is described: design elements, technological elements, basic elements, as well as a mathematical model based on which the calculation of the values of the criteria for choosing a rational option.
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Date submitted2019-01-17
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Date accepted2019-03-20
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Date published2019-06-25
Improving methodological approach to measures planning for hydraulic fracturing in oil fields
Goal of the research is development of an integrated approach to the planning of hydraulic fracturing (HF) treatment taking into account geo-technical, hydrodynamic, technological and economic criteria for the selection of wells for inclusion in the programs of HF with increasing importance of economic criteria. Stages of formation of the program for HF of the oil company are selected, systematized and analyzed. It is shown that high potential effectiveness of enhanced oil recovery method in fields with hard-to-recover reserves, on the one hand, and the complexity and high cost of application, on the other, determine the need to optimize the parameters of this business process at all stages of implementation and improve its planning methods. The priority directions for improving the hydraulic fracturing planning were justified: a clear definition of the criterion for the payback period of hydraulic fracturing activities, taking into account their technological features, improving the procedure for calculating the costs of implementing this technology and improving the reasonableness of selecting candidate wells for inclusion in the hydraulic fracturing program. Feasibility of using an additional criterion in the formation of hydraulic fracturing programs – marginal minimum cost-effective wall capacity – has been shown and a method for calculating it has been developed. The use of this criterion will allow to take into account not only technological limitations, but also limits of economic efficiency of conducting hydraulic fracturing at each specific well and, at the preliminary selection of candidate wells, exclude a priori unprofitable measures.
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Date submitted2019-01-23
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Date accepted2019-03-17
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Date published2019-06-25
Development of the composition of the process fluid to eliminate bit seizure
- Authors:
- E. A. Rogov
During well construction, one of the most complicated types of accidents is the bit seizure as a result of which oil and gas companies incur significant losses due to the abandonment of a portion of the drill string in the well, cutting of an additional wellbore, and sometimes loss of the well. In the case of the elimination of seizure due to packing a positive result can be achieved by pumping portions of the process fluid into the seizure area. Destruction of the packer during the physicochemical effect of the process fluid, in general, allows for complete or partial softening of the packer, changing the pressure in the seizure area and significantly reducing the force required to release the stuck tool. The article presents the results of laboratory studies on the effect of various compositions of process fluids on the packer to eliminate the bit seizure. The effectiveness of the packer destruction was estimated by reducing the tangential stresses after the physicochemical effect of various compositions of process fluids for the same period. A 10% aqueous solution of hydroxyethylidene diphosphonic acid with an addition of 0.5% surfactant alpha olefin sodium sulfonate is recommended as a process fluid to eliminate packer seizures.
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Date submitted2018-11-18
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Date accepted2019-01-17
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Date published2019-04-23
Calculation of elastoviscoplastic displacement of well walls in transversal and isotropic rocks
- Authors:
- A. G. Gubaidullin
- A. I. Moguchev
The relevance of the work is justified by the need to improve the technical and economic indicators of well construction based on forecasting and preventing drilling tools sticking due to the narrowing of an open well bore in the intervals of transversely isotropic rocks. A mathematical model of elastic-viscous-plastic displacement of the walls of inclined and horizontal wells has been developed during the narrowing of the open borehole due to rock creep in the intervals of transversely isotropic rocks. In the program developed based on this mathematical model, the calculation of the elastic-viscous-plastic displacement of the walls of an obliquely directed and horizontal well in the reservoir of argillite from the Western Siberia deposit was carried out. As a result of the calculation, it was established that after opening the rock with bits, the cross-section of the open borehole due to the rock creep eventually takes the form of an ellipse, the small axis of which is in the plane of the upper wall of the well and decreases with time.
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Date submitted2018-11-05
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Date accepted2019-01-01
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Date published2019-04-23
Features of elementary burst formation during cutting coals and isotropic materials with reference cutting tool of mining machines
- Authors:
- V. V. Gabov
- D. A. Zadkov
- Khac Linh Nguyen
The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.
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Date submitted2018-09-07
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Date accepted2018-11-08
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Date published2019-02-22
Assessment of refractory gold-bearing ores based on interpretation of thermal analysis data
- Authors:
- T. N. Aleksandrova
- G. Heide
- A. V. Afanasova
The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented. The obtained fragments for kerogen CH (m/z = 15), C 2 H (m/z = 29) and C 3 H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods. Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia.
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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 submitted2018-01-15
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Date accepted2018-03-24
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Date published2018-06-22
Designing of well trajectory for efficient drilling by rotary controlled systems
- Authors:
- M. V. Dvoinikov
The main directions of increasing the efficiency of drilling wells by improving methods for designing profiles of directional and horizontal wells are identified. The feasibility and necessity of using at drilling with rotary controlled systems the trajectories of directed wells' profiles with continuous curving, that do not contain conjugated sections, on the basis of plane transcendental curves are theoretically substantiated and experimentally confirmed. An algorithm and software are developed that allow optimal selection of a profile or a trajectory section, taking into account minimization of twisting, bending, compressive and tensile stresses that ensure the efficiency of technical and technological parameters of well drilling.
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Date submitted2016-09-01
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Date accepted2016-11-05
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Date published2017-02-22
Research on technical and technological parameters of inclined drilling
- Authors:
- M. V. Dvoinikov
An analysis of operational capabilities of inclined drilling equipment and technology is presented. Two options of rotary drilling are reviewed as technical and technological solutions, facilitating construction of wells with difficult profiles. The first option implies that the driver unit of the drill bit is represented by downhole drilling motor, the second one utilizes sophisticated rotary steerable systems. Practical results of drilling wells with difficult profiles are presented. A quality assessment of drilling is provided through the example of comparing designed and actual trajectories, using different driver units for the drill bit, as well as properties of surrounding rocks, rheology of the drill fluid and other characteristics of dynamically active systems. A range of rotation speed has been determined that allows rotary steerable systems to have minimal oscillation amplitude of the bottom-hole assembly. Analysis of investigation results showed that the main source of oscillations is linked to bending and compressing stresses, caused by well deviations as well as rigidity of the drilling tool. In effect, in the bottom-hole assembly occur auto-oscillations, making it impossible to correct azimuth and zenith angles. Alteration of rigidity in the bottom part of the tool and drilling parameters, implying reduced rotation speed of the drill string and regulation of drill bit pressure, can partially solve this problem, though increase in rotation speed is limited by technical characteristics of existing top drive systems.
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Date submitted2016-09-18
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Date accepted2016-11-04
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Date published2017-02-22
Development of methods of analytical geometry of a sphere for solving geodesy and navigation tasks
- Authors:
- G. I. Khudyakov
The article develops ideas and formulas of analytical geometry for spherical surface of the Earth globe in relation to main tasks of global geodesy and navigation. It examines peculiarities of sphere inner geometry and properties of its primary, secondary and higher-order curves. It was proved that spherical hyperbola and parabola are spherical ellipses with specific parameters. The Cartesian ordinates were introduced into the sphere and the relation between them and polar spherical coordinates was established. With the help of central projection of sphere points on tangential plane the corresponding elliptical plane with beltrami ordinates was introduced. The article describes main formulas of analytical geometry for projected elliptical plane, which correspond to geometry of projected sphere. It also introduces several formulas for primary, secondary and higher-order curves for this sphere.
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Date submitted2015-08-25
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Date accepted2015-10-24
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Date published2016-04-22
The modern technology of drilling and casing of well during the exploration of gas hydrates
- Authors:
- N. I. Nikolaev
- Lyu Tyanle
In the paper, the perspectives of exploration and completion of gas hydrate fields and the drilling problems in the gas hydrates of the northwest china are studied. It has been established, that the main reasons of complications in the Muli field are the secondary hydrate formation on the walls of the well and drilling assembly and ice formation inside the set cement during the well drilling and completion in permafrost. It has been shown, that in the areas with permafrost during the drilling of the layers containing gas hydrates, temperature and pressure changes can lead to the dissociation of hydrates. At the same time, pressure increase in the annular space due to the gas release, can lead to the secondary formation of gas hydrates, drill string stuck, ceasing of drilling fluid circulation, which is the reason of serious trouble in the wellbore. The results of the research on the development of drilling fluids compositions, which lower the drilling troubles of permafrost, are presented. Comparative experiments have been conducted to evaluate the effectiveness of thermodynamic and kinetic inhibitors, which prevent the repeated hydrate formation. It has been established, that the kinetic inhibitors have the clear advantage: they have good inhibiting effects even with low amounts of additives. In the laboratory conditions, the researches have been conducted to evaluate the phase equilibrium of gas hydrates during their reaction with the water solutions, containing kinetic inhibitor PVP. A thin clay drilling mud has been developed on the water base, providing the holding of the temperature in the level of –2 °С and its effectiveness for the gas hydrate fields in the PRC has been shown. Casing effectiveness of unstable rocks during the drilling in the conditions of negative temperatures inside the well largely depends on their physical-mechanical properties, composition and the technical indicators of cement materials. The authors suggest the composition of quick-setting cements based on aluminum binding materials. It has been established, that the analyzed compositions have the ability to considerably improve the results of cementing.