INSULATION OF WATER FLOWS AND INTERVAL TREATMENT OF THE FORMATION IN CONDITIONS OF CRACK-PORE COLLECTORS

Мировая нефтепромысловая практика показывает, что в условиях неоднородных трещинно-поровых пластов высокопроницаемые интервалы, доля которых составляет обычно 30 - 40 %, зачастую являются и основными путями опережающего обводнения скважин, что является очень большой проблемой, требующей привлечения дополнительных материальных ресурсов по борьбе с обводнением скважин и коррозией нефтепромыслового оборудования. The world oilfield practice shows that in the conditions of heterogeneous fractured-porous formations, high-permeability intervals, the share of which is usually 30-40%, are often the main ways of anticipatory watering of wells, which is a very big problem requiring additional material resources to combat water-cutting and corrosion of oilfield equipment.

Effect of Impact Modifiers on Strength and Fracture Toughness of CFRPs

The aim of this work is to study the effect of core-shell rubbers on the mechanical properties of CFRPs.For the preparation of composites, two types of resins were used, a three-component Araldite resin (resin-hardener-accelerator system in proportions of 100-90-0,5 by weight respectively), and MX 156, which contains 25 % core-shell elastomers and 75 % Araldite resin. Depending on the mechanical test, two types of carbon fibre fabrics (UD C415, G0926) are used with corresponding number of layers. The composites were prepared by vacuum infusion and cut to the appropriate dimensions by water-cutting. They were tested for mechanical performance, by bending, shearing, tensile, impact and fracture toughness tests, to compare the properties of CSR-containing composites and reference CFRPs. Fracture analysis of specimens was performed by scanning electron microscopy (SEM). The results exhibited a 50% increase in impact strength while the energy absorbed during the fracture toughness test was 4 times greater on specimens with CSR than reference.

Study on the relationship between the water cutting rate and the remaining oil saturation of the reservoir by using the index percolating saturation formula with variable coefficients

The water cutting rate is recorded dynamically during the production process of a well. If the remaining oil saturation of the reservoir can be deduced based on the water cutting rate, it will give guidance to improve the reservoir recovery and can save expensive drilling costs. In the oil–water two-phase seepage experiment on core samples, the oil and water relative permeability reflects the relationship between the water cutting rate and water saturation, that is, percolating saturation formula. The relative permeability test data of 17 rock samples from six seal coring wells in Daqing Changyuan were used to optimize and construct the coefficients of the index percolating saturation formula that vary with the pore structure parameters of reservoirs, to form an index percolating saturation formula with variable coefficients that is more consistent with the regional geological characteristics of the reservoir. Based on this, the formula of water saturation calculated by the water cutting rate is deduced. And the high-precision formula for calculating the irreducible water saturation and residual oil saturation by effective porosity, absolute permeability, and shale content is given. The derivative formula of water saturation on the water cutting rate was established, and the parameters of 17 rock samples were calculated. It was found that the variation velocity of water saturation of each sample with the water cutting rate presented a “U” shape, which was consistent with the actual characteristics that the variation velocity of the water saturation in the early, middle, and late stages of oilfield development first decreased, then stabilized, and finally increased rapidly. The research results were applied to the prediction of remaining oil saturation in the research area, and the water saturation about six producing wells was calculated by using their present water cutting rates, and the remaining oil distribution profile was predicted effectively. The analysis of four layers of two newly drilled infill wells and reasonable oil recovery suggestions were given to achieve good results.

Effect of the Recyclate on a Deflection of Composites in Bending

The aim of the research was to determine the effect of polyester-glass recyclate on the deflection of composite samples subjected to three-point bending. The polyester-glass recyclate was obtained from the part of the ship’s hull made of polyester-glass composite, constituting scrap metal. The pieces of scrap were pre-fragmented and then processed into a prepared stand for this purpose. Such a fragmented recycling will be used to make composites with different scrap / recycled content. For this purpose, research materials were made using the vacuum bag method with the percentage of 0%, 10% and 20% recyclate) as well as various granulation (i.e. 1.2 mm and 3.0 mm). The research material consisted of rectangular plates with a thickness corresponding to the thickness of the samples. The samples for testing were made by water cutting. The tests were carried out on a suitably prepared stand, which was made of a universal Zwick Roell testing machine and three-point bending handles and a dial indicator. The spacing of the supports has been determined in accordance with the binding standard for three-point bending. Obtained results from tests, i.e. strain, stress, deflection, deformation allowed analysing the impact of recyclate on bending strength and defining the deflection arrow. Based on the results obtained from three-point bending, it can be concluded that the polyester-glass recycling has an influence on the decrease of strength, stress and deflections of the tested composites.

Assessment of the physical load of the waterjet operator using the G. Lehmann method

Basic parameter characterizing the body's workload (in particular physical work) is the energy expenditure, which determines the amount of energy used to perform a specific job (in kcal or kJ). The purpose of this work was to determine the energy expenditure at the station of a water-cutting machine using the tabular-timing method according to G. Lehmann. As part of the author's own research, the position of the waterjet operator was described, taking into account the basic hazards present in the work environment and the requirements regarding occupational health and safety. The paper also presents the results of the energy expenditure assessment and their analysis, which allowed to propose corrective and preventive actions.

Interrelationship between stilbene producing ability and Aspergillus colonization on selected peanut (Arachis hypogaea L.) genotypes

ABSTRACT Stilbenes are phytoalexins expressed by plants to avoid/resist certain biotic and abiotic stresses. This study was envisioned to determine the interrelationship between stilbenes producing ability of peanut genotypes and Aspergillus colonization level. Stilbenes were induced in peanut cotyledon in vitro by soaking in water, cutting them into thin slices, and subsequently challenging them with Aspergillus flavus. Fungal colonization was then measured in the cotyledon slices. The results showed major differences in fungal colonization levels between the control (seed without stilbene induction) and stilbenes-induced seeds. This finding was further validated using twenty peanut genotypes to ensure the relationship between stilbenes producing ability of the seed and fungal colonization level. The result showed that of the 20 genotypes tested, seeds of genotypes K1504, K1620 and K1632 showed minimal fungal colonization compared to control seed (without stilbenes induction), while genotypes DRT40, Kadiri-7, Narayani, DRT43 and Tirupati-3 showed no fungal colonization. The differences in stilbenes content and composition of cotyledon slices was determined by HPLC to assess genetic differences in their stilbenes producing ability. Comparative evaluation of these data showed that the genotypes that showed no fungal colonization expressed significantly higher amounts of stilbenes compared to genotypes which expressed relatively lower amounts of stilbenes. Overall, these data suggest that the genotypes expressing high amounts of stilbenes were able to mitigate fungal colonization while the genotypes expressing relatively lower amounts of stilbenes sustained fungal colonization, which indicates that this technique may be useful for screening breeding population to identify genotypes capable of avoiding Aspergillus colonization and aflatoxin contamination.