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Date submitted2023-07-07
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Date accepted2023-12-27
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Date published2024-12-25
A new insight into recording the mineral composition of carbonate reservoirs at well killing: experimental studies
Well killing operation remains an important technological stage before well workover or servicing, during which filtrate penetrates the bottomhole area of the formation. The impact of process fluids and their filtrate on rock has a significant influence on permeability and porosity of carbonate reservoirs, which decrease due to fines migration. There are few known scientific studies of the interaction of killing fluid filtrate with carbonate rock and fines migration. In our experiments, an aqueous phase was used which is the basis for well killing in pure form, for the preparation of blocking agents and is used in reservoir pressure maintenance system. Core samples taken from the pay of the reservoir were used to simulate the well killing process with generation of reservoir thermobaric conditions. Killing fluid filtrate was kept for seven days, which characterizes the average workover time at flowing wells in the fields of the Perm Territory. Using micro-X-ray tomography and scanning electron microscope, images were obtained before and after the experiment, which allowed confirming a decrease in total number of voids due to fines migration and, as a consequence, a decreasing permeability of samples. Measurement of pH and fines concentration in the aqueous phase was performed before and after the experiment and pointed to mineral reactions occurring as a result of rock dissolution. The results of experiments made it possible to record a decrease in permeability of carbonate samples by an average of 50 % due to clogging of void space and migration of fines (clayey and non-clayey).
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Date submitted2023-04-29
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Date accepted2023-10-11
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Date published2023-10-27
Pink-violet diamonds from the Lomonosov mine: morphology, spectroscopy, nature of colour
The article presents the results of the first comprehensive study of mineralogical and spectroscopic (IR, PL, EPR) characteristics of diamonds from the Lomonosov mine (Arkhangelskaya pipe) with a unique pink, pink-violet colour. It is shown that all crystals belong to the IaA type, with a total nitrogen content in the range of 500-1500 ppm, with a low degree of aggregation. The colour is heterogeneous, concentrated in narrow twin layers. It is presumably caused by the previously described M2 centres. The colour shade is affected by the content of P1 paramagnetic centres (C-defect). A positive correlation is observed between the colour saturation and the intensity of W7 paramagnetic centres. A convergent model of the formation of pink diamonds is assumed, according to which the determining factors are the ratio and concentration of structural impurities in the diamond, its thermal history, and conditions of plastic deformation, and not the origin of the diamond and the petrochemical properties of its host rocks.
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Date submitted2021-05-27
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Date accepted2022-09-06
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Date published2022-11-10
Application of resonance functions in estimating the parameters of interwell zones
It is shown that the use of force resonance leads to the effect of “shaking” the formation, followed by breaking up the film oil and involving it in the further filtration process. For the first time in oilfield geophysics, the concept of passive noise-metering method is justified for monitoring oil and gas deposit development by measuring the quality factor of the contours in the point areas of formation development channels in interwell zones. It is established that determining the depth of modulation for the reactive substitution parameter of the linear FDC chain is crucial not only for determining the parametric excitation in FDC attenuation systems, but also without attenuation in the metrological support for the analysis of petrophysical properties of rock samples from the wells. It is shown that based on the method of complex amplitudes (for formation pressure current, differential flow rates, impedance), different families of resonance curves can be plotted: displacement amplitudes (for differential flow rates on the piezocapacity of the studied formation section), velocities (amplitudes of formation pressure current) and accelerations (amplitudes of differential flow rates on the linear piezoinductivity of the FDC section). The use of predicted permeability and porosity properties of the reservoir with its continuous regulation leads to increased accuracy of isolation in each subsequent sub-cycle of new segment formation in the FDC trajectories, which contributes to a more complete development of productive hydrocarbon deposits and increases the reliability of prediction for development indicators.
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Date submitted2017-10-27
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Date accepted2018-01-01
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Date published2018-04-24
Method of induction control of iron weight fraction in magnetite ore
- Authors:
- I. N. Bazhenov
- O. O. Basov
This paper analyzes the peculiarities of existing methods and means of induction control of magnetic susceptibility of the medium are analyzed. It is concluded that these means have a common drawback due to the low measurement accuracy caused by the wave-like dependence of the instrument sensitivity on the gap between the probe and the medium surface. The ways of increasing the instrument sensitivity and measurement accuracy of controlled parameters by means of inductive measuring transducers are revealed. A method for induction resonance control of iron weight fraction in magnetite ore has been developed, and its effectiveness has been estimated using simulation modeling. Practical recommendations for the development of quality control instruments for magnetite ores have been developed. A variant of the quality control unit layout for working with magnetite ores is proposed.
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Date submitted2017-08-30
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Date accepted2017-11-23
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Date published2018-02-22
Basic provisions and problems of ELW technology for the manufacture of aluminum-magnesium alloys constructions
- Authors:
- E. I. Pryakhin
- N. I. Sharonov
Existing problems of electron beam welding of aluminum alloy constructions are considered. For research purposes, the aluminum-magnesium alloy of grade 1561 up to 60 mm thick was used. The thermal field in the heat influence zone is studied experimentally and analytically on the basis of the finite element method (the «Ansys» program). The effect of electron beam movement (scanning) influence on the quality of welded connections and the surface of the welded parts was studied. On the basis of metallographic studies and mechanical tests of welded metal, it is proved that high quality of welded joints is ensured when the beam moves along a curve of the «compressed brackets» shape. A special generator is designed to control the electron beam, which allows to implement a new type of scanning (compressed brackets). The fundamentals of welding technology for alloy 1561 up to 60 mm thick are outlined. Specific recommendations are given, and two new methods are proposed that will allow the successful use of the developed technology in factories in the production of new products and in the repair processes. Examples and analysis of thermal cycles obtained by calculation and experimental method are given. The patterns of heat distribution along the trajectory of the beam movement for different types of scanning are established. The main types of defects in the formation of the welded joints and those formed in the metal during crystallization are considered. Their interrelation with the parameters of the welding mode is shown.
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Date submitted2015-12-28
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Date accepted2016-02-28
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Date published2016-12-23
Ion distribution function in their own gas plasma
- Authors:
- A. S. Mustafaev
- V. S. Sukhomlinov
Flat one-sided probe was used for the first time to measure the first seven coefficients in the Legendre polynomial expansion of ion energy and angle distribution functions for He + in He and Ar + in Ar under the conditions when the ion velocity gained along its free run distance is comparable to the average thermal energy of atoms. Analytic solution of the Boltzmann kinetic equation is found for ions in their own gas for arbitrary tension of electric field in plasma when the dominating process is resonant charge exchange. The dependence of cross-section of resonant charge exchange on the relative velocity is accounted for. It is demonstrated that the ion velocity distribution function differs significantly from the Maxwell distribution and is defined by two parameters instead of just one. The results of computational and experimental data agree quite well, provided the spread function of measurement technique is taken into account.
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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 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 submitted2010-07-20
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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 submitted2010-07-19
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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 submitted2009-08-05
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Date accepted2009-10-21
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Date published2010-02-01
The autoresonant electric drive of the swinging movement pendular vibration exciter vibration jaw crushers
- Authors:
- Yu. A. Gavrilov
- E. A. Zagrivnyi
To use of the autoresonant electric drive of swinging movement for creation of an oscillative motion of crushing jaws of vibrating jaw crushers it is offered in this article. The control system of the electric drive is developed. The results of imitating and physical modelling of the autoresonant electric drive are presented.