Improving the waterproofing efficiency by using a plugging compound

Increasing the efficiency of water shut-off works is one of the important tasks for the sustainable well operation. The article discusses the use of various plugging compositions for water inflow into a well isolating, their advantages and disadvantages, conditions of use, and presents the results of a study of the proposed composition. The composition of an aqueous solution of polyaluminium chloride and a suspension of gypsum anhydrite is considered. The composition contains 45-55 mass percent of 15-25 percent aqueous solution of polyaluminium chloride and 45-55 mass percent suspension of gypsum anhydrite at a water-solid ratio of 0.9. The technical result is an increase in the efficiency of water inflow into the well isolating by obtaining a homogeneous, dense plugging mass formed by mixing the components of the composition and gaining maximum strength over time. Keywords: well; water cut; isolation; water inflow; plugging mass; bottomhole formation zone; oil production; polyaluminium chloride; anhydrite.

Use of plasma treated basalt fiber as a concrete additive

The paper investigates the effect of plasma treatment of basalt fiber on its hydrophilic behavior, which was estimated by contact angle. The pre-chopped basalt fiber was put in a soft polyethylene container to prevent fiber particles from being carried away by a flow of plasma gas, and to protect outlet gas ducts against clogging. It was evaluated what effect the plasma modification had on the strength properties of BST V40 P2 concrete. As the treatment time increases the contact angle becomes higher until treatment time reaches 10 minutes. The contact angle-treatment power dependence passes through a maximum. The highest value has been observed at a treatment power of 0.6 kW both on the day of treatment and after a 5-day rest period. The wettability of basalt fiber after 5 days of exposure after the first wetting leads to lower results, but remains at a fairly high level. The retreatment after a 5-day curing period yields lower results, but the level remains sufficiently high. The highest contact angle has been observed at a treatment power of 0.6 kW, gas flow rate (G) of 0.04 g/s, chamber pressure (P) of 20 Pa, with air/argon mixture (1:1) as plasma gas. Were tested samples of concrete BST V 40 P 2 with the addition of plasma-treated basalt fiber in the amount of 0.5 and 3% of the mass. on the strength index under two modes of basalt fiber processing: in mode 1 the treatment time was 10 minutes, the treatment power was 1.5 kW; and in mode 2 the treatment time was 5 minutes, the treatment power was 0.6 kW, with the addition of plasma treated basalt fiber (0.5 and 3 mass percent). It was found that the plasma treatment of basalt fiber before chopping gave concrete a higher strength than plasma treatment followed by chopping. Concrete has the highest strength when basalt fiber (3 mass percent) is subjected to plasma treatment in mode 2. Furthermore, the strength increased by 23 mass percent in comparison with the reference sample.

Experimental validation of the reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zinc-rich dust process

The reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zincrich dust process are studied. The dust collected from a steelwork contains 63.8% zinc and 3.18% chlorine (mass percent), of which, almost all zinc elements exist in ZnO and ZnCl2 forms, and all the chlorine elements are stored in ZnCl2. When the dust is roasted at above 732∘C in an air atmosphere, the ZnCl2 in the steelmaking zinc-rich dust is volatilized into steam and then oxidized into ZnO. Finding the position where the chemical reaction occurs is the key to determining the reaction mechanisms of dechlorination and [Zn] reclaiming. In this study, two groups of thermal experiments are designed and executed for roasting in different atmosphere environments and at different roasting temperatures. Based on the experiment results, the mechanism model is discussed and built, and the reaction of dechlorination and [Zn] reclaiming is shown to be a multi-step process. Because O2 from the air cannot transmit into the dust particle interior or dust bed effectively, the chemical reaction of [Zn] reclaiming occurs in the external gas environment outside of the dust, where the [Zn] recalcining reaction should be limited by the dynamics of new nucleation of ZnO solids.

Composite Materials Based on Plasma Treated Basalt Fibers for Heavy-Duty Concrete Products

The paper investigates the effect of plasma treatment of basalt fiber on its wettability, which is determined by the ability to absorb water. As the treatment time increases the wettability becomes higher, up to 10 minutes. The wettability-treatment power dependence passes through a maximum. The highest value is observed at a treatment power of 0.6 kW both on the day of treatment and after a 5-day rest period. A further growth in power not only does not increase this value, but in fact decreases it. The retreatment after a 5-day curing period yields lower results, but remains sufficiently high. The highest wettability is observed at a treatment power of 0.6 kW, gas flow rate of 0.04 g/s, chamber pressure of 20 Pa, air/argon mixture (1:1) as plasma support gas. The strength of concrete specimens BST V40 P2 was tested with two treatment modes: in mode 1 the treatment time was 10 minutes, the treatment power was 1.5 kW; and in mode 2 the treatment time was 5 minutes, the treatment power was 0.6 kW, with the addition of plasma treated basalt fiber (0.5 and 3 mass percent). Concrete has the highest strength when basalt fiber (3 mass percent) is subjected to plasma treatment in mode 2. In addition, the strength increases by 18 mass percent in comparison with the reference.

Dietary Energy Density is Associated with Body Mass Index and Fat Mass in Early Adulthood

A cross-sectional study was conducted to investigate the association between body composition parameters as well as body mass index (BMI), and dietary energy density in a population of 538 young adults. Fat mass, fat mass percent, fat-free mass, and visceral fat were measured using a body composition analyzer. Daily energy intake was assessed using a 72-hr diet recall, and dietary energy density was calculated. Significant differences in dietary energy density among underweight, normal-weight and overweight/obesity young adults were identified ( M = 1.42, SD = 0.26 vs. M = 1.52, SD = 0.46 vs. M = 1.66, SD = 0.53, p = .002). Dietary energy density was associated with BMI (β = .961; CI 95% = 0.335, 1.586; p = .0030), fat mass percent (β = 1.921; CI 95% = 0.707, 3.135; p = .002), and fat mass (β = 2.146; CI 95% = 0.827, 3.466; p = .001). Dietary energy density might be considered as an important aspect in the obesity nutritional education programs in young people.

Wear Resistance of Steels after Diffusion Saturation of Boron, Chrome and Titanium

In this work, the wear resistance of hardened simultaneous diffusion saturation on S235J0, C45, 55NiCrMoV6, C80W1 and X162CrMoV12 steels with boron, chromium and titanium and rigidly fixed abrasive Al2O3 particles were investigated. Wear was determined by measuring the loss of mass every 30 seconds of the test. Full wear of the layer occurred in 10 minutes with a load on the sample of 9.5 MPa. According to the test results, it is found that the wear resistance of alloyed steels increases as the content of alloying elements and carbon increases, but this increase is not unambiguous because of a decrease in the thickness of the diffusion layer as the degree amplification of alloying steels. Taking into account the economic parameters, such as the cost of steel, the cost of manufacturing products, we can conclude that the greatest economic effect shape can be achieved when using the hardening steels with a carbon content of 0.5 mass percent and the total content of alloying elements up to 5 - 7 mass percent.

Influence of Tempering and Cryogenic Treatment on Retained Austenite and Residual Stresses in Carbonitrided 18CrNiMo7-6 Low Alloy Steel

This work investigated the influence of tempering conditions coupled with cryogenic treatment on thermal stabilization of retained austenite and residual stress distributions in carbonitrided 18CrNiMo76 low alloy steel samples. The carbonitriding conditions were set to enable attaining surface carbon and nitrogen content of 0.87 and 0.34 mass.-percent respectively. After carbonitriding, some of the samples were subjected to varying tempering conditions followed by cryogenic treatment at -120 °C using nitrogen gas. Analysis of both retained austenite and residual stresses was conducted using X-ray diffraction. In the as-quenched state, carbonitrided samples contained 52 mass.-percent. Samples that were directly subjected to the cryogenic treatment after quenching retained only about 20 mass.-percent of austenite. Samples subjected to variant tempering conditions coupled with cryogenic treatment retained at least 30 masses.-percent of austenite. A thermal stabilization of retained austenite which increases with increasing temperature was identified. On tempering at 240°C for 14 hours retained austenite becomes unstable and decomposes to bainite leading to the low initial amount of retained austenite before cryogenic treatment. It can be concluded that the tempering process coupled with cryogenic treatment leads to an increasing hardness, to higher compressive residual stresses as well as to a shift of the location of maximum compressive residual stress toward the surface.

Collective synthesis of the CaB6‒TiB2 heterogeneous powders

The heterogeneous CaB6‒TiB2powder blends were synthesized by means of the TiO2and CaCO3mixture boron carbide reduction under vacuum at 1400‒1650 °C, and reactive hot pressing was used according to the condition: 1500 °C (synthesis in vacuum) ‒ 1900 °C (Argon pressing). As a result of the CaB6‒TiB2synthesis with the mass ratio 1:1 at 1600 °C and isothermal time 1 hour the heterogeneous mixture was prepared which contained the CaB6and TiB2crystal phases as well as the residual B4C admixture (0,5 mass percent). The powder particles were the grains 1‒3 micrometers in diameter containing two phases CaB6and TiB2as the micro crystals 0,1‒1,0 micrometers in diameter uniformly spaced over the particle volume.Ill. 6. Ref. 37. Tab. 1.

Phase formation at the Ti2AlN under the spark-plasma sintering in the Ti/AlN system

The synthesis of the Ti2AlN-based material by means of the mechanical activation (MA) of the Ti‒AlN powder mixture in the planetary mill followed by the vacuum spark-plasma sintering (SPS). It was shown that the phase ratio AlN/Ti gradually decreases under mechanical activation. The data are given on the sample's phase composition, density and hardness after the SPS. The maximum Ti2AlN content value of 90 mass percent was achieved at the SPS temperature 1300 °C. The samples had the lowest porosity value of 1,9 % at the SPS temperature 1200‒1300 °C, the HV0,5hardness being close to 7 GPa.