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Date submitted2022-10-13
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Date accepted2022-12-13
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Date published2023-07-19
A complex model of a drilling rig rotor with adjustable electric drive
A modified mathematical model of an asynchronous electric drive of the rotor – a drill string – a bit – a rock is considered and implemented, which develops and generalizes the results of previously performed studies. The model includes the following subsystems: a model of an asynchronous drive with vector control; a model of formation of the resistance moment at the bottom of the bit, taking into account the peculiarities of the interaction between the bit and the rock; a model of a multi-mass mechanical part that takes into account the deformation of the drill string; subsystem for the drilling rig energy-technological parameters formation. The integrated model makes it possible to calculate and evaluate the selected drilling modes, taking into account their electro-mechanical, energy and technological efficiency and the dynamics of drilling processes. The performed computer simulation of drilling modes confirmed the possibility of a stick-slip effect accompanied by high-frequency vibrations during bit stops, which may change the direction of rotation of the bit, its accelerated wear and unscrewing of the drilling tool. Long bit stops lead to a significant decrease in the average bit rotation speed, which can explain the decrease in the ROP and increase in energy consumption when drilling in the zone of unstable bit rotation. The model can be used as a base for further improvement of rotary drilling control systems.
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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 submitted2021-10-15
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Date accepted2022-09-06
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Date published2022-11-10
Experimental research on the thermal method of drilling by melting the well in ice mass with simultaneous controlled expansion of its diameter
- Authors:
- Danil V. Serbin
- Andrey N. Dmitriev
During the seasonal work of the 64th Russian Antarctic Expedition in 2018-2019 at the “Vostok” drilling facility named after B.B.Kudryashov (“Vostok” station, Antarctic) specialists of Saint Petersburg Mining University conducted experimental investigations on the process of drilling by melting with simultaneous expansion of wells in the ice mass. A test bench and a full-scale model of a thermohydraulic reamer-drilling tool were developed, manufactured and tested for the research. The first bench tests of the full-scale model proved its efficiency and suitability for experimental drilling with simultaneous expansion of wells in ice mass; its operational capabilities were determined and the drawbacks that will be taken into account in future were found out. The article substantiates the choice of constructive elements for thermohydraulic reamer-drilling tool. It is determined that the technology of full diameter drilling with simultaneous expansion of the well in ice mass can be implemented by combining contact drilling by melting and convective expansion with creation of forced near-bottomhole annular circulation of the heated heat carrier. Dependencies of expansion rate on main technological parameters were determined: active heat power of heating elements in penetrator and circulation system, mechanical drilling rate, pump flow rate. According to the results of investigations, the experimental model of thermohydraulic reamer-drilling tool will be designed and manufactured for testing in conditions of well 5G.
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Date submitted2021-10-18
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Date accepted2022-01-24
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Date published2022-04-29
Development of a hydrocarbon completion system for wells with low bottomhole temperatures for conditions of oil and gas fields in Eastern Siberia
The paper presents the results of investigations on the influence of low bottomhole temperatures in the intervals of productive formations on the technological properties of solutions used for drilling and completion of wells in order to determine the possibility of increasing gas recovery coefficient at the field of the “Sila Sibiri” gas pipeline. The analysis of technological measures determining the quality of the productive horizon drilling-in was carried out. It was found out that the dispersion of bridging agent in the composition of the hydrocarbon-based drilling mud selected from the existing methods does not have significant influence on the change in the depth of filtrate penetration into the formation in conditions of low bottomhole temperatures. The main reason for the decrease in the near-bottomhole zone permeability was found out – the increase in plastic viscosity of the dispersion medium of the hydrocarbon-based drilling mud under the influence of low bottomhole temperatures. A destructor solution for efficient wellbore cleaning from hydrocarbon-based solution components in conditions of low bottomhole temperatures was developed. The paper presents the results of laboratory investigations of hydrocarbon-based drilling mud and the developed destructor solution, as well as its pilot field tests. The mechanism of interaction between the destructor solution and the filter cake of the hydrocarbon-based drilling mud ensuring the reduction of the skin factor in the conditions of the geological and hydrodynamic structure of Botuobinsky, Khamakinsky and Talakhsky horizons of the Chayandinskoye oil and gas condensate field has been scientifically substantiated.
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Date submitted2019-11-28
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Date accepted2020-05-08
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Date published2020-10-08
Development of the drilling mud composition for directional wellbore drilling considering rheological parameters of the fluid
Article presents investigations on the development of a drilling mud composition for directional wells in an oil field located in the Republic of Tatarstan (Russia). Various rheological models of fluid flow and their applicability for drilling muds are analyzed. Laboratory experiments to measure the main rheological parameters of a solution, such as plastic viscosity, dynamic shear stress, as well as indicators of non-linearity and consistency are presented. On the basis of laboratory investigations, it was concluded that high molecular weight polymer reagents (for example, xanthan gum) can give tangible pseudoplastic properties to the washing fluid, and their combination with a linear high molecular weight polymer (for example, polyacrylamide) reduces the value of dynamic shear stress. Thus, when selecting polymer reagents for treating drilling muds at directional drilling, it is necessary to take into account their structure, molecular weight and properties. Combination of different types of reagents in the composition of the drilling mud can lead to a synergistic effect and increase the efficiency of the drilling process as a whole.
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Date submitted2019-09-25
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Date accepted2019-12-20
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Date published2020-04-24
Study of the well near-bottomhole zone permeability during treatment by process fluids
- Authors:
- Evgenii A. Rogov
In the process of drilling-in productive horizons, several irreversible physical and chemical processes take place in the near-wellbore zone of the formation: stress state of the rocks changes, penetration of the filtrate and solid phase, as well as drilling mud into the reservoir, and swelling of clay particles of intergranular cementing material are observed. As a result, permeability of productive horizon is significantly reduced and, consequently, potential inflow of oil or gas from formation is excluded. An equally serious problem exists during well servicing and workover, when the use of irrational fluids of well killing causes negative consequences associated with deterioration of reservoir properties of formations in the wells being repaired. Article presents the results of the experiments on permeability of clayed porous samples after exposure to various compositions of liquids. In order to increase permeability of near-borehole zone of the formation and increase productivity of wells completed by drilling, and after well servicing and workover, a composition of the process fluid containing a 15 % aqueous solution of oxyethylene diphosphonic acid (OEDA) with addition of a surfactant is proposed.
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Date submitted2018-11-09
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Date accepted2019-01-22
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Date published2019-04-23
Determining the stability of the borehole walls at drilling intervals of loosely coupled rocks considering zenith angle
- Authors:
- P. A. Blinov
During development of drilling projects, a whole array of data is needed considering the properties of rocks and the conditions of their bedding. Accounting for geomechanical processes occurring in the near-wellbore zone allows avoiding many complications associated with the violation of the wellbore walls stability at all stages of its construction and operation. Technological and technical factors such as vibration and rotation of the drilling string, formation of launders during the descent and ascent of the assembly, pressure pulsation during the start and stop of pumps, hydrostatic and hydrodynamic pressure of the drilling fluid, its composition and properties, have a great influence on the stress-strain state of the medium opened by the well. The washing fluid circulating in the well should provide backpressure to the reservoir, not interact with the rocks chemically, colmatage channels in porous and fractured rocks, preventing penetration of the mud into the medium, by creating an impermeable barrier at drilling clay seams that are prone to swelling, cracking, etc. The article discusses the method for determining the stability of the directed well walls, taking into account the penetration of drilling mud into the pores and fractures of rocks. The technique will allow adjusting the zenith angle of the well during the workout of an unstable interval at the design stage, or selecting a drilling fluid composition to ensure fail-safe drilling.
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Date submitted2018-09-01
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Date accepted2018-10-28
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Date published2019-02-22
Mathematical modeling of rock crushing and multiphase flow of drilling fluid in well drilling
The aim of the work is a mathematical modeling of the rock crushing during drilling and removal of the drilling cuttings (sludge) to the surface by drilling fluid. The process of rock destruction is described using the mathematical theory of fragmentation. The distribution of sludge particles in size and mass depends on such factors as the properties of the drilled rock, the rate of penetration, the type of bit, and the output power. After the formation of sludge, the process of its removal to the surface is modeled. The drilling fluid together with the rock particles is considered as a heterogeneous multiphase medium in which the carrier phase – the drilling fluid – is a non-Newtonian fluid. The flow of such a medium is described using a mixture model in the framework of the multi-fluid approach. This results in a system of nonlinear partial differential equations, for which a new closure relation is derived. To solve the system, the SIMPLE algorithm is used. As a result, the flow properties are studied with the inclusion of particles of various sizes. In particular, for particles of small size due to the action of plastic stresses in a non-Newtonian drilling fluid, an equilibrium mode arises in which the particles move with the drilling fluid without slipping. This is the fastest mode of delivery of sludge to the surface. The specific dimensions of such particles depend on the parameters of the drilling process. In particular, the appropriate size range can be adjusted by changing the parameters of the drilling fluid.
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Date submitted2018-05-04
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Date accepted2018-07-23
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Date published2018-10-24
Analysis of possible enhancementof properties of VK15 material used for drilling tools
- Authors:
- Yu. A. Kurganova
- K. S. Panina
- P. S. Beshenkov
Traditionally, when drilling hard and abrasive rocks, it is recommended to use a tungsten-cobalt hard alloy VK15. The analysis of information on the possibility of improving the potential of the material has demonstrated the existence of mechanisms that provide structural transformations that enhance its strength, hardness and toughness. The use of such technology instead of traditional methods will lead to an increase in the operating efficiency and durability of the tool. During the work, experimental samples of alloy VK15 were obtained by sintering in four different modes. Then their properties were analyzed. The results of the metallographic study carried out on the «Carl Zeiss» microscope made it possible to estimate the distribution of tungsten carbide grains in cobalt bon and show the grinding of the carbide phase. Thus, with traditional sintering, the amount of tungsten carbide grains with an average size of less than 1 μm in diameter from the entire size range reaches 19.5 %, while after additional heat treatment with a holding time of 1280 °C, the value was 41.5 %; 900 °C – 59.1 %; 600 °С – 54.5 %. The maximum improvement results were the following: hardness by 18 %, a coercive force by 49 %, and crack resistance by 11 % of the traditional alloy, there were achieved at 900-1280 °C. A hypothesis has been put forward on the formation of additional structural elements not detected by the methods of optical metallography. Studies of the topology and structure of the samples on an atomic force microscope confirmed the presence of nanoscale inclusions from 20 to 40 nm (presumably tungsten carbide) in a cobalt bond.For VK15, comparative studies of properties and analysis of the microstructure of experimental samples obtained by the traditional sintering and modified technology have shown that the sintering mode at 900 °C is a priority.
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Date submitted2018-01-02
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Date accepted2018-03-14
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Date published2018-06-22
Analysis of the options of modernization of roller-bit drilling machines with a submersible steamer
- Authors:
- D. A. Yungmeister
- I. Krupenskii
- S. A. Lavrenko
The designs of submersible hammers and dampers protected by patents for reducing the vibration of the drilling rig of roller drill machines are proposed. The variants of modernizing drilling rigs for drilling hard rocks and faces of complex structures are considered. Particular attention is paid to the joint work of submersible shockers and pneumatic shock absorbers, the preferred schemes for the arrangement of these devices by drilling rigs are indicated. The results of experimental tests of machines with pneumatic hammers are presented to determine the vibration performance and drilling speeds. The pneumatic hammer allows increasing the speed of drilling process to the intensification of the destruction of the plain face by the shock load and the cleavage of the protrusions of the unevenness of the face, the better fitting of the bit to the face and the release of the blades or the bit pins from the drill bit. The choice of a particular type of damper or shock absorber depends on its design scheme and the possibility of changing the design of the drill string. With the complexity of installing a damping device in the mast (with significant dimensions of shock absorbers and drilling of strong heterogeneous rocks), it is advisable to use a set of tools to reduce hydraulic pulsations in the mains and cylinders of the hydraulic system by installing chokes in the oil plants and pneumatic shock absorbers. It is proposed to use the device for the development of pneumatic hammers by a patent-pending drilling method with a hollow piston filled with magnetically active heavy liquid, which will allow controlling the frequency and size of the shock pulses and partially compensating for the drill string fluctuations arising from the uneven immersion of the bit in the array . It is noted that the proposed solutions increase the drilling speed by an average of 15%.
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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.
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Date submitted2010-07-19
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Date accepted2010-09-22
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Date published2011-03-21
Simulation of swinging movement autoresonant electric drive with nonsymmetric excitation
- Authors:
- A. N. Fomenko
Mathematical and simulation models of drill bit oscillations. Method for calculating the model works elastic, electromagnetic and load torques has been developed. Simulation results of autoresonant regimes with asymmetric excitation oscillations of dynamically counter balanced drilling string on the cargo-carrying cable drill bit are represented.
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Date submitted2010-07-20
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Date accepted2010-09-14
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Date published2011-03-21
The physical breadboard model of dynamically counterbalanced drilling string with swinging movement with the asynchronous electric drive powered by inverter laboratory experimental researche
- Authors:
- V. V. Ivanik
The laboratory experimental stand for research of the asynchronous resonant electric drive on a physical breadboard model of dynamically counterbalanced drilling string is developed. The asynchronous electric drive with swinging movement the autoresonant oscillation mode is realized.
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Date submitted2010-07-21
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Date accepted2010-09-28
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Date published2011-03-21
Swinging movement autoresonant electric drive with nonsymmetric excitation of dynamically counter-balanced drilling string on carrying cable
- Authors:
- E. A. Zagrivnyi
- A. N. Fomenko
Considered nonsymmetric mode of drill bit oscillations when forming a unipolar electromagnetic torque on each cycle oscillations of dynamically balanced drill . Developed a method for estimating speed of rotation drill around its axis when working in the nonsymmetric mode at first approximation .
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Date submitted2010-07-08
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Date accepted2010-09-02
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Date published2011-03-21
The autoresonant asynchronous electric drive of dynamically counterbalanced drilling string on carrying cable with swinging movement fluctuations amplitude stabilization
- Authors:
- E. A. Zagrivnyi
- V. V. Ivanik
The algorithm of resonant fluctuations amplitude stabilization of dynamically counterbalanced drilling string on carrying cable with swinging movement of jackbit is developed. Imitating modeling of the resonant asynchronous electric drive with swinging movement of jackbit with the frequency converter in various operating modes is resulted.
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Date submitted2009-08-15
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Date accepted2009-10-19
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Date published2010-02-01
Modern magnetic quality monitoring and the forecast of the technical condition of engineering constructions
- Authors:
- A. N. Lyubchik
On terrain of Russia act a system of mains by a general expansion more than 200 thousand km. More than halves oil and gas pipelines are in exploitation 25-35 years, i.e. demand immediate repeated examination and conforming preventive maintenance. Intraube magnetic or the ultrasonic flaw detection for these purposes is not always possible and is dear enough, therefore last years a urgency of application of remote geophysical methods has increased at service oil and gaspipeline of the transport sharply. These methods are express enough and more economic.