Oilfield Equipment Research Articles

RESEARCH OF WEAR RESISTANCE AND MECHANISM OF ABRASIVE WEAR OF GAS THERMAL METALLIZED COATINGS USED FOR SEM PROTECTION

Complicated operating conditions of oilfield equipment during oil production using ESPs require the use of additional measures to protect its main components from the effects of negative factors. One of the main and significant negative factors influencing the corrosive aggressiveness of the environment is the water cut of the produced oil, which contains a large amount of dissolved gases, such as carbon dioxide and hydrogen sulfide, which are characterized by high corrosive aggressiveness and are the main risk factors leading to corrosion of the oil field. equipment and their premature failure. The housings of submersible electric motors (SEM) are the most susceptible to corrosion of the ESP unit. According to statistics, about 70% of failures occur in the motor housing. Of the variety of protection methods, the application of gas-thermal metallization coatings is the most widely used for protecting motor housings. Despite the effectiveness of this method of protection, it does not exclude the occurrence of corrosion processes in the metal of the motor housing and possible damage and destruction. This article is devoted to studies of the corrosion behavior of various types of metallization coatings used to protect SEDs under the influence of one of the main aggressive components — carbon dioxide dissolved in the mineralized aqueous phase, by conducting autoclave tests that simulate in laboratory conditions the operation of the material, in particular its corrosion resistance when exposed to a corrosive environment.Conducting research in this area is an urgent task aimed at solving the problems of reducing the service life of oilfield equipment and their premature failure, in particular motor drive housings during operation in difficult conditions.

STUDY OF CONDITIONS FOR GAS HYDRATE AND ASPHALTENE-RESIN-PARAFFIN DEPOSITS FORMATION IN MECHANIZED OIL PRODUCTION

Link for citation: Korobov G.Y., Vorontsov A.A. Study of conditions for gas hydrate and asphaltene-resin-paraffin deposits formation in mechanized oil production. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 61-75. In Rus. The relevance of the research is caused by the lack of study of gas hydrates and asphaltene-resin-paraffin deposits formation in the borehole space. The properties of the organic deposits formed significantly depend on conditions of their formation. Accordingly, more accurate understanding of principle of deposits formation allows predicting their agglomeration and selecting effective ways to combat the deposition of gas hydrates and asphaltene-resin-paraffin deposits. In addition, information presented in the article makes it possible to evaluate the effect of the main factors affecting the conditions of gas hydrates and asphaltene-resin-paraffin deposits formation. There is an opportunity to point out the most important factors, which can be controlled by changing the parameters of the downhole equipment. These studies can help to optimize selection of downhole equipment parameters in the conditions of organic deposits formation. The main aim of the research is to analyze the conditions of gas hydrate and asphaltene-resin-paraffin deposits formation in production well; to analyze the results of previous studies on the factors affecting the formation of gas hydrates and asphaltene-resin-paraffin deposits in the borehole space. Objects: factors affecting formation of gas hydrates and asphaltene-resin-paraffin deposits on inner surface of the oilfield equipment. Methods: literature review of publications in peer-reviewed journals; analysis of the results of previous studies, formulation of main ideas and trends, identifying gaps and shortcomings of existing researches. Results. The main mechanisms of gas hydrates and asphaltene-resin-paraffin deposits formation on inner surface of the oilfield equipment are described. A review of previous studies devoted to the analysis of formation mechanisms of asphaltene-resin-paraffin deposits and gas hydrates is presented. The analysis revealed gaps and assumptions in the theory of formation of gas hydrates and asphaltene-resin-paraffin deposits, which require further study of their formation principles. The main factors that depend on the operation of downhole equipment, as well as affecting the formation of organic deposition are analyzed: thermal baric conditions, gas content, throttling, watering, molecular phenomena. These factors are summarized in separate tables.

Introduction the technology of selective formation water isolation using gel-forming systems

During the development of heterogeneous reservoirs as a result of unimpeded water filtration from highly permeable formations, premature watering of wells occurs. Increase of water in the composition of well products leads to premature failure of oilfield equipment, reduction of the time between repairs, additional costs during production of well products and, along with these, to loss of oil. Various technologies and compositions are used to prevent well watering. Short-term technological efficiency, limited ability to regulate the isolation process and high prices of reagents reduce the efficiency of compositions implementation. In order to increase the efficiency of isolation of water inflow into the well, to block high permeable and involvement in the development of low-permeable oil zones of the reservoir, laboratory tests of a new composition based on the use of a solution of 9–10 % sodium silicate and 10–12 % hydrochloric acid have been carried out. The composition developed for the purpose of isolation of water inflow into the well has a possibility to regulate both the process of gel formation and time. The composition was tested in field conditions and positive results were obtained.

DEVELOPMENT AND APPLICATION OF NEW COMPOSITIONS TO IMPROVE THE EFFICIENCY OF OIL FIELD EQUIPMENT OPERATION

One of the urgent problems in the oil industry is the reliable protection of oil field equipment from corrosion. With this in mind, as a result of laboratory studies, three compositions were developed based on phospholipids, fatty acids, phosphoric acid, nitrogen compounds, asidol, naphthenic acids and light gas oil. The complexity of the composition gives the resulting compositions multifunctionality and allows them to be used in various aggressive conditions.
 In laboratory conditions, the effect of these compositions on the corrosion rate of metals and on the vital activity of sulfate reducing bacteria (SVB) was studied. Based on the obtained results, the concentration of the compositions (500 mg/l) was established, providing a protective effect against corrosion, which was 94–95 %, and the degree of suppression of SVB was 97–99 %.
 Field tests of corrosion inhibitors also yielded positive results: the protective effect against corrosion was 89–90 %, and the degree of SVB suppression was 92–97 %.

Development of Methods for Optimization and Machine Design of the Connecting Unit of Oil-Field Equipment

Development of Methods for Optimization and Machine Design of the Connecting Unit of Oil-Field Equipment

Development of Methods for Optimization and Machine Design of the Connecting Unit of Oil-Field Equipment

It was determined experimentally that to provide complete sealing, the value of the contact pressure on the sealing surface must be three times greater than the internal pressure. The tightness of flange connections is provided by creating the necessary pressure on the sealing surfaces of the flanges. Moreover, the required specific pressure is created in the seals by tightening the bolts fastening the flanges. The amount of leakage is influenced by the surface roughness and the accuracy of the manufacturing of the sealing elements.

CITRIC ACID USAGE FOR INDUSTRIAL SAFETY INCREASE

The problem of mineral salt deposition is one of the most significant in the operation of oil fields. Salt deposits can lead to production downtime, an emergency situation and serious threat to personnel safety. To date, there are various methods of salt formation preventing. Chemical protection methods using inhibitors have become the most widespread. Despite the successes in the application of this type of protection, the accident rate remains at a high level. In this regard, the inhibitory protection effectiveness increasing remains relevant.The article suggests the use of citric acid (CA) as a co-inhibitor of salt deposits. The purpose of this work is to study the effectiveness of citric acid usage to prevent salt deposit formation and increase the level of industrial safety of oilfield equipment.This article describes a new method of combating salt deposits and presents the results of experimental studies to assess the citric acid effect on the salt deposition inhibitor (SDI) effectiveness. SDIs have been tested for their ability to prevent the salt formation. The ISO effectiveness was determined by the trilonometric method. It has been shown that one of the inhibitors in the dosage range of 30–100 g/t has extremely low protective properties, but with the citric acid addition, its effectiveness has increased. The best results of the protective effect of 75 % were achieved using citric acid and the second inhibitor.According to laboratory test results, a positive effect of citric acid on the inhibitor effectiveness was revealed. It has been experimentally proved that citric acid can be used to protect oilfield equipment from salt deposits.

Correlational Extremal System for Controlling the Beginning of Faults in Oil Field Equipment by Analyzing their Wattmeter and Dynamometer Charts

The creation of technology for the analysis of wattmeter charts to control the main equipment of oil fields has always been of both theoretical and great practical interest. Numerous experiments have shown that the wattmeter chart of their electric motor is a highly noisy signal, and a significant part of the diagnostic information is contained in the estimates of the noise variance and the cross-correlation function between the noise and the useful signal. The lack of technologies for their analysis made it difficult and still makes it difficult to use the wattmeter chart to control the indicated equipment. The paper proposes a technology for controlling the onset of malfunctions and early diagnostics of the technical condition of sucker rod pumping units (SRPU), electric submersible pumps (ESPs), modular cluster pump stations (MCPS) of oil fields. It is shown that during operation, the wattmeter chart of the electric motors of these objects reflects information about the beginning of the latent period of change in their technical condition, which can be used as informative attributes in their diagnosis. A technology is proposed for determining the estimate of the cross-correlation function RXε(μ) between the useful signal X(iΔt) and the noise ε(iΔt) of the wattmeter chart and the technology for generating a set of reference wattmeter charts, in which the obtained informative attributes coincide with the informative attributes of the wattmeter charts of typical malfunctions. It is proposed to solve the problem of identifying faults in the equipment under consideration by the informative attributes of current and reference wattmeter charts of electric motors using correlation extremal systems. It is shown that using the proposed technology it is also possible to control the onset of similar malfunctions of SRPU by analyzing the dynamometer chart. The results of experiments showing the effectiveness and expediency of creating these control systems based on CES are presented.

RESEARCH ON THE TECHNOLOGY OF PREPARING PLASTIC AND THREADED COMPONENTS USING 3D PRINTING OR ADDITIVE MANUFACTURING

Threaded components play a crucial role in ensuring the safety and reliability of systems by joining components together. Proper selection of thread type and size, ensuring proper machining and storage of components, and addressing potential issues such as leakage, vibration, and misalignment all play a special role. It is known that there is a big difference in the nature of the destruction of metal and plastic threaded connections, in particular, when the nut is made of plastics, and the bolt is made of steel, or vice versa. In this regard, at present there is no consensus in assessing the strength of plastic threaded connections. On the one hand, it is recognized that, due to a more uniform distribution of the load, plastic threaded connections have a significant load capacity. Numerous examples of the use of plastic threaded connections in pressure pipelines, in large plastic parts subjected to dynamic loads, various loaded fasteners - all these examples confirm that plastic threaded connections can withstand very high loads. Production of a thread of plastic details is rather difficult, than on metals. It is connected with the physical-mechanical processes coming in the course of production of concrete thread details from plastic by method of pressing and casting under pressure. Also mechanics of formation of plastic threads on details of the oil-field equipment on the specific properties differ from the threads received by a machining method on metals. As thread surfaces on plastic details are formed in compression molds depending on materials and the modes: temperatures, pressure and time of production. These regime parameters and guided parameters play a part at a guaranty of physicalmechanical properties of details in the course of production. The use of plastic or polymer threads in the oil and gas industry is increasing due to their unique characteristics and advantages over traditional metal threads. Recently, 3D printing (additive manufacturing) has become more widely used for the preparation of plastic threads. The article will discuss the methods and characteristics of preparing plastic threaded components, as well as their advantages and certain incompatibilities. Keywords: threaded components, plastic threaded components, preparation methods, 3D and 4D printing.

Original article Machine learning in the analysis of the electromagnetic field influence on the rate of oilfield equipment’s corrosion and salt deposition

Introduction. The formation of salt deposits and oilfield equipment’s corrosion in most oil fields has become particularly relevant due to the increase in the volume of oil produced and the increase in its water content in recent years. The deposition of salts in the formation and wells leads to a decrease in the permeability of the oil reservoir, the flow rate of wells. The aim of the work is to use machine learning algorithms to simulate the effects of an electromagnetic field on the processes of salt deposition and corrosion. Prediction of experimental results will allow faster and more accurate experiments to establish the influence of electromagnetic fields on the processes of corrosion and salt deposition.Materials and methods. Three groups of data were used, to train the models, differing in the composition of the studied initial model salt solution: the waters of the Vyngapurovsk’s and Priobsk’s deposits, as well as tap water. The following machine learning models were used: linear regression with Elastic-Net regularization, the k-nearest neighbors algorithm, the decision tree, the random forest and a fully connected neural network.Results. The processes of electromagnetic field influence on the formation of salt deposits and corrosion of oilfield equipment were simulated with the help of machine learning algorithms. Python program has been developed to predict the output results of experiments. Modeling with various models and their parameters is carried out.Discussion and conclusions. It was found that the decision tree and the random forest have the best accuracy of predictions, from the experiments conducted. This is due to the fact that there is too little data in the training samples. With the increase in the number of observations, it is worth using neural networks of various architectures.

Estimation of the Possibility of Application of Polymer-Composite Materials in Oil Field Equipment under Abrasive Action

Currently, composites with a polymer matrix are most widely used in various industries, including the oil and gas sector, as an alternative to traditional metal materials. The most widespread of non-metallic pipes in the Russian Federation are pipelines made of fiberglass. One of the clear advantages of polymeric materials over metal products is their corrosion resistance. At the same time, upon contact with liquids containing abrasive particles, composites with a polymer matrix can degrade with varying degrees of intensity. Such as type of degradation like hydroabrasive wear of pipelines is common and can lead to equipment failure. Various linings are applied to the inner surface of fiberglass pipes to minimize hydroabrasive wear. This study attempts to assess the durability of coated and uncoated composite polymer materials under conditions of hydroabrasive wear, as well as to compare the properties with other materials currently used in industry.

DEVELOPMENT OF RECOMMENDATIONS FOR IMPROVING THE INSTALLATION SUITABILITY OF PUMPING UNITS USED IN THE REPAIR AND RESTORATION WORK OF WELLS

Oilfield pumping units are often subjected to a periodic full cyclein the performance of technological operations, namely: transportation., installation, operation of equipment and dismantling, for transportation and repetition of the entire cycle. For equipment located on mobile vehicles, periodic installation is characteristic. At the same time, during the installation of oilfield equipment, deviations from technical conditions are characteristic, which lead to accelerated failures, their reliability and resources decrease. To ensure a high level of installation suitability, it is required to have a specific concept, which is the concept of installation suitability. The purpose of the work is to develop recommendations for improving the installation suitability of pumping units used in the repair and restoration work of wells. Based on the results of the work carried out, it was concluded that the suitability for installation and manufacturability of installation are among the important indicators of processing oil and gas field equipment, significantly affecting reliability, labor productivity during maintenance, current and aggregate-node repairs; operating costs and efficiency of equipment use. Keywords: installation suitability, testing, production, indicator, oilfield equipment.

QUALITY STUDIES OF PLASTIC PARTS OILFIELD EQUIPMENT

The article considers the quality of plastic parts of oilfield equipment depending on the modes of manufacturing their various designs and the composition of press materials. By adjusting the regime parameters in the manufacture of parts, quality indicators are determined: tensile strength, hardness of parts, and others. The use of parts made of plastic materials for the development of the oil field equipment industry can be considered efficient from a technical and economic point of view. Also, in order to improve the quality, strength and longevity, plastic masses, which are an alternative product to metals and non-metals, have started to be used. Studying the performance indicators of the used plastic materials is considered mandatory. The quality of details made of plastic masses depends on many factors, and the indicators of these factors appear during operation. The quality indicators of products made of plastic materials in oil field equipment are distinguished by the presence of unlimited possibilities, greater than structural materials. Parts made of such materials have high performance indicators and are used in the preparation of parts with different constructions using uncomplicated processing methods. For the development of the oil industry, ways to increase the durability and longevity of the equipment used in this industry should be investigated. Based on the results, an experimental-theoretical method for determining the main quality criteria (shrinkage deformation and other quality indicators, strength, hardness, surface roughness) of plastic parts is proposed. The developed technique for the design of plastic parts makes it possible to estimate the expected life of parts, taking into account their operating conditions. Keywords: quality, plastic parts, press materials, performance, shrinkage.

SYNERGETIC EFFECT OF STRENGTHENING POLYMER NANOCOMPOSITES

According to the cluster model of glassy polymers, in the amorphous state they are natural nanocomposites of two components of a loosely packed matrix and nanoclusters immersed in it, respectively playing the role of a matrix and filler in a natural composite. In this interpretation of the polymer, an important role is played by the dimensional effect of nanoclusters, identical to the specified effect of a nanofiller in an artificial nanocomposite, namely, a decrease in the size of both nanoclusters and dispersed particles leads to a sharp increase in the degree of amplification (modulus of elasticity) of the nanocomposite. In this paper, using parallel and sequential microcomposite models, upper and lower fractal estimates for the elastic modulus of the matrix are obtained and the synergistic effect of strengthening the elastic modulus of the nanocomposite as a whole as a superposition of the amplification effects from inorganic filler and from nanoclusters playing the role of filler of the loosely packed matrix is quantified. The object of research in this work is a packer - a device designed to disconnect two zones of the borehole and isolate the internal space of the production column from the impact of the borehole environment. The tightness of the packages is achieved thanks to sealing elements (SE), for the manufacture of which a composite with the composition is used: a mixture of synthetic butadiene nitrile and hydrogenated butadiene nitrile rubber (BNC + HBNC), vulcanizer, stabilizer, technological additives and copper nanoparticles. For the class of polymers under consideration, a rule has been developed for choosing the most preferred model from the above two micromechanical models at a given temperature. Keywords: oilfield equipment, synergetic effect, cluster model, natural nanocomposite, interfacial region, inter-component adhesion, loosely packed matrix.

INCREASING THE FLUSHING SAFETY OF THE DRILLING PROCESS AND THE PERFORMANCE OF SEALING ELEMENTS OF BLOW OUT PROTECTION EQUIPMENT

The article is devoted to the study of the choice of the most effective control of technological processes for the prevention and elimination of gas, oil and water intrusions based on establishing the reliability, performance and durability of blowout control equipment. In this regard, the technical condition of the sealing elements of rams preventers, which generally meet all the requirements for the normal performance of blowout safety tasks, is of paramount importance.In order to evaluate and predict the performance and durability of the ram preventer's sealing elements, the basis for conducting experimental studies of their technical condition should be developed.To develop the basis for conducting experimental studies of the technical condition of the sealing elements of ram preventers in order to assess and predict their performance and durability. In this regard, for research, the main parts and components of the stand for testing standard drilling oilfield equipment were developed and manufactured. Structurally, the stand consists of two test wells with a depth of 2000 and 2500 meters, respectively. The structure of the wellhead equipment of each well includes a casing head with installed anti-blowout equipment (ram and annular hydraulic preventers together with a hydraulic drive station). A standard drilling rig and a rig for running a drill string into a pressurized well are installed at the test wellheads. In addition, the stand includes specially designed and manufactured additional components and assemblies: pumping units, suction and discharge manifolds, a circulation system equipped with a number of additional devices and mechanisms, etc. Moreover, an integrated hardware and software complex has been developed specifically for the stand for monitoring and recording information during experimental studies. This complex ensured fast processing of the results of experimental studies on a computer, reliable storage and retrospective access to data, quick readjustment and the possibility of parallel work with several test objects. It is a guide for the experimental study of the productivity and durability of the sealing elements of ram preventers and provides a set of measures for determining the technical condition of BOP during operation based on objective indicators. Keywords: Blowout preventer, ram, preventer, sealing element, heavy-duty.

The study of surface roughness of plastic details operated in oil field equipment

The quality of the plastic details of the oil field equipment is predominantly characterized with the operation properties, such as high strength, low roughness of surface, wear-resistance, high resistance to the aggressive medium and, finally, high technological capacity that makes polymers irreplaceable for using in various engineering constructions. Moreover, the quality of the plastic details is formed mainly in the process of their manufacturing. Therefore, the control on the stability of changing of the technological parameters of preparation process is essential. If the defects revealed, and shortcomings of some parameters in a final product cannot be eliminated then the imperfections revealed can be corrected in time due to the changing of technological regimes. Based on the results obtained, the optimum regimes for a specific brand of plastic details applied in the oil field production are recommended.

Analysis of mechanical impurities contained in pumped liquids at the fields of Western Siberia

Purpose of the study: analyze the mechanical impurities contained in the pumped liquids. To achieve this goal, the paper set the task of conducting a physicochemical analysis of the composition of solid deposits on parts that come into contact with an aggressive liquid. Scientific hypothesis Improving the reliability of field pipeline and pumping hydraulic systems is one of the most important tasks in oil production. In addition to oil, a significant amount of corrosive fluid is increasingly released from the reservoir during production, damaging the parts through which it passes. This naturally leads to the appearance of the most important complication during operation - deposits of paraffins and hydrates. The article is devoted to the study of the mineralogical and granulometric composition of mechanical impurities that destroy the pipeline network and pumping hydraulic system in the fields of Western Siberia. In this paper, mechanical impurities contained in pumped liquids at the Samotlor and Khokhryakovskoye fields are analyzed. Premature failure of the productive operation of the equipment is due to the aggressiveness of groundwater injected into the reservoir. A physicochemical analysis of the compositions of solid deposits on damaged parts of oilfield equipment was carried out - a laboratory analysis of the granulometric and mineralogical composition of mechanical impurities was carried out. Appropriate conclusions are drawn . Proposed measures to prevent the processes of salt deposition.

ASSESSMENT OF CORROSION DAMAGE TO OIL-WELL TUBING IN MINERAL ENVIRONMENTS

The state of oil production technology and engineering, especially in the conditions of well operation with complex aggressive environment, requires solutions that allow to improve productivity processes without maximising costs. One of the reasons reducing effective well performance can be attributed to the formation of a corrosion layer formed on the surface of oilfield equipment. Mineral salts in formation waters together with other non-carbons form electrochemical corrosion activity on the surface structure of metal. As a result, there is a decrease in the strength of the metal of the tubing pipes in the well, the formation of cracks in the threads, as well as a decrease or complete loss of productivity. The effects of corrosion on pumping units can lead to emergency situations at oil production facilities. Currently, at the Kumkol oil field, the issue of increasing the strength of production equipment when working in conditions with high water content and mineral salt content in the composition has not lost its relevance. The purpose of this article is to determine a method for carrying out a set of anti-corrosion measures in the region with the destruction of metal tubing pipes and well pumps based on monitoring technological processes at oil enterprises.

Application of new repair technology in the restoration of plungers of borehole rod pumps

The durability of oilfield equipment (OFE) depends on a number of factors, including the reliability of the design, the perfection of their manufacturing technology, the level of use of modern technologies in repair and restoration and other works. When restoring machine parts whose service life has expired, modern methods such as laser, ironing, flame gas, etc. are currently used in repair production, which create the basis for a serious impact on their resources. Of great importance is the technology of restoring parts - the method of ironing. In the processes of restoration of large-sized, cabinet, metal-intensive parts, etc. The article presents the results on increasing the resistance of the plunger-cylinder pair to abrasion and increasing the service life due to the use of ironing technology. Keywords: rod depth pump; abrasion resistance; plunger; cylinder; ironining.

Metody obliczeń wytrzymałości zmęczeniowej części maszyn

Regardless of the operating conditions, a load acts on the parts of a machine in different directions. These loads in particular determine the required strength and resistance of parts and determine the study and selection of appropriate strength, resistance parameters for the parts. This can be determined by their impact on oilfield equipment and machine parts. Testing is done to determine the static flexibility, flow limit, tensile strength relative to flexibility, strength period limit, and plastic deformation coefficient. In some cases, when the limits of wear of machine parts are equal, elements with a larger coefficient of deformation are more convenient. These regularities should be used in those cases when it is possible to apply the methods of fracture mechanics or when there are direct experimental data on the development of fatigue cracks, which make it possible to carry out a probabilistic assessment of the durability of structural elements at the stage of crack growth and to substantiate the corresponding limitations on the service life of products. For the safety margins of machine parts, the starting points are as follows: longitudinal bending stress in the sleeve of a solid machine part made of a plastic material cannot damage the part. The length of the first crack can be taken to be equal to several millimetres, which is determined by the capabilities of the simplest means of observation, and by the fact that in some cases even a crack of such length can be critical from the point of view of a potential brittle fracture. In this regard, the fatigue resistance characteristics used in such a calculation should correspond to the point at which the first macroscopic crack appears.