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One of the main problems of the modern oil and gas industry is to increase the degree of extraction of hydrocarbons from fields. As a solution, various methods of enhanced oil recovery are being introduced. One of the promising methods is the vibration impact on the formation by downhole vibration sources, in which the working force on the casing string is transmitted using hydromechanical power elements. During operation of the power element, its elastic chamber experiences a complex stress-strain state under the action of high pressure of the working fluid. To perform calculations of dynamic processes in a load-bearing element and select the optimal design parameters during design, it is necessary to know the dependence of the volumetric modulus of elasticity of an elastic chamber on the acting pressure. The paper describes the experimental technique and the results of determining the bulk modulus of elasticity of an elastic chamber under working deformations.

Creation of downhole sources of elastic vibrations for the implementation of vibrowave enhanced oil recovery methods is an urgent task of mining engineering. The paper substantiates the expediency of using an electromagnetic linear drive of a downhole vibration source to generate axial shock pulses. A mathematical model is proposed that describes the dynamics of movement of the striker of electromagnetic impact unit under the action of traction forces of coils, friction forces and aerodynamic resistance, taking into account the elastic constraints at the end of the lower and upper working strokes of the striker. Theoretical dependences of striker displacement and speed on time, obtained using the developed model, are presented, and their high convergence with the experimental data is shown. The mathematical model of electromagnetic impact unit can be used to optimize its parameters, as well as to design new standard sizes of vibration sources that meet the requirements of the oil and gas industry.

The study analyzes the influence exerted by the body, guide and their materials on the pull strength of electromagnets in electromagnetic hammers. The pull strengths of electromagnets without positive and negative poles are evaluated.

Advancement of wave action stimulation and cross-well seismic imaging in mineral mining governs the need for downhole sources of elastic vibrations. The presented periodic electromagnetic seismic source is equipped with a mechanical–hydraulic drive for fixturing in a hole and for impulse transition to rock, and an electromagnetic impactor for pressure pulse generation. This article presents the experimental studies into the operation of the seismic source of three structural layouts. The features of the operation are discussed. The supply voltage dependences of the main parameters of the seismic source are obtained, and the practical application recommendations are formulated.

The article presents a case-study of mathematical modeling of electromagnetic and electromechanical processes in a downhole vibration exciter EM drive. The authors propose the mathematical model of EM drive on the basis of a double-acting EM machine. This model maintains a wide-range analysis of transient and quasi-stable operating regimes. The algorithm and implementation of the model using the structural modeling methods and means in the Matlab Simulink environment are described. The model verification is carried out by means of comparison of the simulation and physical models of EM drive within the configuration of downhole pulse vibration exciter. The appropriateness of the model is proved. The authors give recommendations on further improvement of the model and its accuracy in calculation of dynamic behavior of drives.

The experimental research of processes running in a linear pulse electromagnetic motor of a downhole vibration generator is described. Based on the research findings, design requirements and recommendations on basic geometrical proportions of the equipment are formulated.

The authors investigate whether it is possible to improve the models of the electric drives of vibration sources using Matrix Laboratory Simulink. The test subject is the simulation model of the electric drive of a borehole vibration exciter based on a linear double-acting electromagnetic machine. The simulation model consists of the power and control subsystem of the electric drive. This model allows the wide-range parametric analysis of processes in the electric drive by the computer modelling methods. The oscillograms of voltages and currents are obtained in the case of the electric drive control by the piston position for real-life and ideal sources of power supply. The oscillograms are compared, and the calculation error is estimated.

The linear electromagnetic machines, which are designed for operating as impact drives in well impulse vibratory sources applied for the impact on oil layers at great depth, have been comprehensively investigated. The lab results of the model operating processes are presented. The demands on the operating processes construction have been formulated with respect to the casing internal diameter limitation in a deep well. In the paper the results of experimental investigation seek to optimize operating mode are presented.