The paper presents the description of an integrated approach, which is implemented in a program module and allows predicting scale deposition in well based on distributions of specific multiphase flow parameters (temperature, pressure, and gas content). Parameters are obtained from calculated pump operation regimes. The method's apparent advantages are presented, namely: -automatic input of reservoir water/gas chemical content data, -numerical estimation of scale deposition risk in different well sections by means of the saturation index, -built-in tips on selecting the optimal scale prevention technology specifying the inhibitor type and amount, -prediction of pump life cycle buildup, -estimation of the expected economic benefit caused by scale prevention. The prediction method of scale deposition and the algorithm of selection of the scale prevention technology can be successfully used during analysis of scale deposition risk and planning the activities for scale prevention for a group of oil wells or oilfield. The proposed algorithmic module has been tested in a number of active oil fields of Western Siberia, and has already garnered positive references from production professionals. This module is planned to serve as a basis for similar modules for forecasting risks of mechanical dashes, corrosion and paraffin buildup.
the paper presents the results of the research that studied how the penetration depth of pitting corrosion in the surface structures of clad steel depends on the steel surface electrode potential. the tests were carried out on the stainless surface of the samples made from steel 09g2S/08X13, which is widely used in production of metal structures for the oil and gas industry due to its necessary mechanical properties and corrosion resistance. the operation process of this steel runs in the technological environment with high corrosivity. the influence of pitting components of the corrosive medium (Сlи S 2 o 3 2ions) on the diffusion of oxidants and the development of local processes of destruction of a passive film is shown. it is noted that the maximum influence of the electrode potential on the development of pitting corrosion occurs in the area of secondary passivation. in this case, the depth of pitting can reach 180 μm. Further displacement of the electrode potential of the surface contributes to the phenomenon of transmissivity and leads to the appearance of significant mechanical stresses in the surface structures, causing their cracking. investigation of surface structures will establish mechanisms for their destruction, and timely implement the necessary anticorrosion measures.
There are many problems when creating digital doubles. One of which is the definition of the source data: in this case, the definition of private reductions (coefficient ratios) in a continuous finishing group of stands of the broadband hot rolling mill 2000 of PJSC Magnitogorsk Iron and Steel Work. Algorithms were developed to calculate the thickness of the breakdown bar, the number of stands involved, power required for rolling and coefficient ratios to solve this problem. The algorithms are based on well-known solutions (the Imai method) using neural networks. The training of neural networks was conducted on a sample collected for the period from 01.01.2017 to 01.01.2019 work of the mill in the PyTorch library of the interpreted programming language Python. The average error εME of the calculation of coefficient ratios (according to the developed algorithms with neural networks) does not exceed 8.9% and the standard deviation σ does not exceed 0.074.
Corrosion activity of the environment is caused by the presence in it of salt ions that are directly involved in the corrosion process causing deposition of inorganic salts on the surface of the equipment. Removal of such active salt ions from the working environment or modifying them from the active to the inactive state signifi cantly reduces the rate of corrosion of the equipment and the amount of salt deposits.The most common cause of damage to oilfi eld equipment is the impact of corrosive environment. Inorganic salt deposits on the surface of the equipment (salt scaling) often cause contamination of the pumped or processed media and reduction of the operational cross-section of the pipeline. Removal of the ions (salts) from the working medium, or their modification from the active state to the inactive signifi cantly reduces the rate of corrosion of equipment and the amount of scaling. Search for low-cost and highly effi cient methods of protection against salt deposits is an important task for the oil and gas industry. Moreover, the search for methods to reduce the corrosiveness of water coming into contact with oilfi eld equipment surfaces is highly relevant.In the development of oil and gas fi elds, a large amount of water is consumed for reservoir pressure maintenance thus prolonging the spouting period and signifi cantly increasing the oil and gas recovery factors of the reservoir. The system of reservoir pressure maintenance (RPM) is a technological equipment complex used for the preparation, transport, and injection of the working reagent and corrosion inhibitors into the petroleum reservoir. For reservoir pressure maintenance, both natural (freshwater and brackish) and sewage (drainage) waters are used, in the composition of which there are reservoir (85%), fresh (10%), and rain (up to 5%) waters. One of the characteristics of wastewater is high content of corrosion-active agents (hydrogen sulfi de, carbon dioxide, oxygen, etc.) that cause destruction of oilfi eld equipment. These gases dissolved in the water lead to the destruction of passive fi lms on the metal and cause depolarization of the cathodic reaction of metal ionization, which leads to the intensifi cation of the corrosion process.High concentration of mineral salts in reservoir environments is another reason for the formation of corrosive agents. For example, upon interaction between calcium sulfate CaSO 4 and methane present in the reservoir, hydrogen sulfi de can be produced. Unlike natural waters, wastewater may contain hydrocarbons and microorganisms, particularly, sulfate reducing bacteria, which reduce hydrogen sulfi de during metabolism.Mineralization of wastewater is mainly determined by the composition of reservoir waters usually categorized into four main types: sodium sulfate, sodium bicarbonate, calcium chloride, and magnesium chloride waters; their mineralization may range from 15 to 250 mg/liter. Calcium chloride reservoir water is found in the oil fi elds most often. The most active ions causing deposition of insoluble sa...
The lysoamidase bacteriolytic complex (LBC) comprising five enzymes (L1-L5) is secreted into the culture liquid by gram-negative bacterium Lysobacter sp. XL1. The medicinal agent lysoamidase has a broad-antimicrobial spectrum. Bacteriolytic protease L1 belongs to the LBC. Recombinant L1 protease of Lysobacter sp. XL1 was expressed, purified to homogeneity and crystallized. The X-ray structure of L1 at 1.35 Å resolution has been determined using the synchrotron data and the molecular replacement method. L1 protease is a thermostable whose thermal unfolding proceeds in one step without forming stable intermediates. Structural information concerning L1 will contribute to the development of new-generation antimicrobial drugs, whose application will not be accompanied by the selection of resistant microorganisms.
Homing endonucleases are a group of site-specific endonucleases that initiate homing, a nonreciprocal transfer of its own gene into a new allele lacking this gene. This work describes a novel phage T4 endonuclease, SegD, which is homologous to the GIY-YIG family of homing endonucleases. Like other T4 homing endonucleases SegD recognizes an extended, 16bp long, site, cleaves it asymmetrically to form 3'-protruding ends and digests both unmodified DNA and modified T-even phage DNA with similar efficiencies. Surprisingly, we revealed that SegD cleavage site was identical in the genomes of segD and segD phages. We found that segD gene was expressed during the T4 developmental cycle. Nevertheless, endonuclease SegD was not able to initiate homing of its own gene as well as genetic recombination between phages in its site inserted into the rII locus.
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