Identification of the possible negative impact of the drilling reagent brucit on workers involved in the construction of wells

Tagirova Kamilla Bulatovna Master's Degree, Department of Industrial Safety and Labor Protection (PBiOT), Ufa State Petroleum Technical University 450096, Russia, Republic of Bashkortostan, Ufa, ul. Enthusiasts, 15, sq. 362 tagirovakamilla@gmail.com

Barakhnina Vera Borisovna PhD in Technical Science Associate Professor, Department of PBiOT, Ufa State Petroleum Technical University 450096, Russia, respublika Bashkortostan, g. Ufa, ul. Entuziastov, 15, of. 362 tagirovakamilla@gmail.com

IntroductionDuring the construction of wells for employees of drilling enterprises, along with the factor of mechanical injury, fire and explosion hazard of circulating substances and special climatic conditions, one of the main hazards and hazards is the need for contact with general-purpose inorganic reagents: acid ammonium phosphate (or diammonium phosphate), ammonium bisulfite and sulfite, calcium bromide and chloride, calcium hydroxide (slaked lime), calcium oxide (quicklime), calcium sulfate (alabaster), gypsum, chromium chloride, chromium-potassium sulfate (chromium or chromium-potassium alum), basic copper carbonate, magnesium chloride, magnesium hydroxide (brucite), magnesium oxide (magnesia, periclase), potassium carbonate, chloride and potassium hydroxide, bicarbonate, carbonate chloride, chromate, sulfite bichromate, sodium hydroxide, bromide, carbonate, oxide, chloride, chromate, zinc sulfate, sodium silicate (liquid glass), etc.

The interaction of drilling reagents with biological components such as nucleic acid molecules, proteins and cells in general leads to their distribution in body tissues, a possible immune response and changes in metabolism ^[1]. At the moment, the number of studies on the effect of drilling reagents of inorganic origin on living organisms is growing. Thus, it has been proven that toxicity depends on the particle size of drilling reagents, that is, the penetrating power increases with their decrease, and, consequently, the biological effect increases. For example, a small amount of a sprayed substance is capable of aggressive inhalation penetration, which is a trigger mechanism for the development of lung inflammation ^[3].

The use of inorganic pulverized chemicals in the preparation of grouting fluids, storage and disposal as part of drilling waste increases the risk of penetration of aerosol particles into the body of workers together with inhaled air, with food, through the pores of the skin and mucous membrane. A significant number of studies have been devoted to morphological changes that occur in the airways and respiratory sections of the lung when inhaling toxic substances. At the same time, the issues of the influence of brucite on the respiratory system are not touched upon, and descriptions of the full picture of violations of the structures of the respiratory system are not presented, which makes the study of this issue relevant. This solid, partially water-soluble powdery reagent is used in the construction of wells to control and stabilize the alkalinity of drilling fluids, as well as for hydraulic fracturing and as an expanding additive to grouting Portland cement used for water insulation in the overhaul of oil and gas wells. The microscopic dimensions of brucite determine its significant penetrating power, which carries a probable danger of harmful effects on the health of employees of oil and gas production enterprises (Figure 1).

As can be seen from Figure 1, the air of the working area contaminated with brucite aerosol is a source of harmful effects on the lungs of drilling company workers. Employees of more than 26 specialties are subject to a possible negative impact: from a drilling rig operator to a well debit meter, a driller of capital repairs, a drilling fluid engineer. Other possible ways of penetration of brucite into the body of an employee of a drilling company are food and water, and the ways of excretion are mainly the intestines and kidneys. The results of the study of the biological effect of aerosol brucite particles on the body of an employee of a drilling company will allow to assess the danger of using this chemical reagent, prevent negative consequences and issue recommendations on the use of individual and collective protective equipment.

Scientific novelty:

In the work, the early unexplored effect of the drilling reagent brucit on the lung tissue of rats was determined. The categories of workers exposed to brucite at all stages of production are determined.

 For the first time, morphological features of the lungs in rats were determined against the background of inhalation administration of brucite particles for 30 days at a dose of 50 mg/kg.

Based on the results of the study, the toxicological characteristics of the drilling reagent brucit are given.

The aim of the study was to determine morphological and morphometric changes in lung tissues in experimental animals with inhalation administration of brucite particles.

To achieve this goal , the following tasks were set:

1) determination of the morphological features of the lungs in non-linearalbinorats rats against the background of inhalation administration of brucite particles for 30 days at a dose of 50 mg/ kg;

2) morphometric analysis of histological sections of the lungs of rats: the control group and the group subjected to inhalation administration of brucite for 30 days at a dose of 50 mg/ kg;

3) on the basis of the obtained results of the study, to give a toxicological characteristic of the drilling reagent brucit.

Materials and methods of researchMagnesium Hydroxide Mg(OH)

₂ (brucite, Brucite) is a white powder, very slightly soluble in water. It is used in drilling fluids as a buffer or stabilizer in acid-soluble fluids for well completion (in combination with polymers) in concentrations from 1 to 6 kg/^m3. In other industries it is used under the names: t alkhydrate – Talkhydrat (Leonhard, 1821), aqueous talc – Wassertalk (Glocker, 1831), magnesia – magnesine (Breithaupt, 1832), hydrophyllite – hydrophyllite (Glocker, 1831), hydrinfyllite – hydrinphyllite (Breithaupt, 1832), texalite (tehalite) – texalite (Herman, 1860), tenardite – shepardite (Brook, before 1896, Hay). Ga (0.0003%) was spectroscopically established in brucite from the chromite-bearing massif of the Southern Urals (Republic of Bashkortostan) ^[1]. It is necessary to avoid inhaling the powder. Irritating to the skin, the pH of the solution is 10.4 ^[2].

The optical density of Mg(OH)₂ sol and the obtained polymer-colloidal dispersions were determined in order to establish the average particle radius of the sol used. The optical density of Mg(OH)₂ sol and the resulting polymer-colloidal dispersions was measured on a KKK-3 photocolorimeter in the wavelength range ?=315-580 nm at t=25 °C. To determine the average radius (r_, nm) of magnesium hydroxide sol particles, the turbidity spectrum method was used ^[4]. Studies have shown that the radius of sol particles is Mg(OH)₂ was in the range of 87-165 nm.

The object of the study: rats of the non-linearalbinorats line of mature age weighing 210-350 grams. According to the rules adopted by the European Convention for the Protection of Vertebrates Used for Experimental and Other Scientific Purposes, experimental animals were kept in a ventilated room at a temperature of 20 ° C, on a standard vivarium diet, with free access to water and food, with light mode 12/12 (lighting from 8.00 o'clock). The selected animals were weighed and randomly divided into 2 groups: group 1 (10 rats) - intact animals (control); group 2 (10 rats) – daily inhalation of brucite (50 mg / kg body weight, 2 ml) for 30 days.

Subject of research: histological lung samples of rats exposed to brucite.

Research resultsThe experiment used an inhalation method of introducing technogenic brucite particles into rat lungs.

Brucite particles present in the air, when inhaled, passed through the nose, trachea, bronchi and reached the alveoli of non-linearalbinorats rats. Obviously, part of the administered dose was excreted by the body with excrement and mucus, and the other part was absorbed and then distributed to organs and tissues. A control section of the bronchus of medium caliber is shown in Figure 2.

14 days after the introduction of brucite particles, changes in lung tissue can be seen on micrographs of the histological section. Focal fullness of the capillaries of the interalveolar septa is revealed. Some interalveolar septa are filled with edematous fluid, in some places they are thickened, they have an increased content of cells (lymphocytes, segmented leukocytes). There are hemorrhages in the interalveolar septa and alveoli. The changes recorded on the 14th day after the introduction of brucite particles are shown in Figure 3.

30 days after the introduction of brucite particles, circulatory disorders increased. Perivascular edema developed. Edematous fluid appeared in the alveoli located in the thickness of the lungs. While the photos of the histological section of the control group of animals showed normal blood circulation, pathologies and changes in the structures of the bronchial and alveolar epithelium were not detected (Figure 4).

As can be seen from Figure 4, in the photos of the histological section of the control group of animals, the alveoli are straightened, and their lumens are free. Interalveolar septa are normal (thin), accumulations of lymphocytes, leukocytes and macrophages on the territory of the lung tissue of the control group are not observed.

Lung preparations when exposed to brucitis on non-linearalbinorats rats for 30 days are shown in Figure 5.

In Figure 5a, you can notice the peeling of the bronchial epithelium. The formation of airless areas alternating with emphysematous dilated areas is observed in the lungs. The effect of brucite particles on rats at 30-day exposure is characterized by a more pronounced macrophage reaction than at 14-day exposure. There is the formation of large peribronchial and perivascular infiltrates containing lymphocytes, macrophages, neutrophils, a few plasma cells and eosinophils. The predominant infiltrate cells are lymphocytes and macrophages. The presence of eosinophils indicates the sensitizing effect of brucite particles.

Comparing the results of morphological studies after inhalation administration of brucite to rats for 30 days, it should be noted that 14-day administration caused less pronounced dystrophic processes in the lungs, compared with 30-day administration. By the 30th day of intoxication, adaptation did not occur.

Next, morphometric analysis of the area of alveoli, bronchioles and perivascular infiltrates in rats was performed. Statistical processing of the morphometric study data was reduced to calculations of the following indicators: for each parameter, the average value (M) and the standard error of the average (m) were calculated. The characteristics of the samples are given in accordance with M ± m and calculations of errors and deviations of the average values. The significance of the differences in the mean values was determined based on the Student's t-test with a high degree of confidence at p<0.001; an average degree of confidence at p<0.01; a low degree of confidence at p<0.05. All the data obtained during the study are statistically reliable and representative both from the standpoint of evidence-based medicine and from the standpoint of analytical morphofunctional analysis.

Table 1 presents the results of morphometric analysis of histological sections of the lungs of rats: the control group and the group subjected to inhalation administration of a dispersed form of brucite for 14 and 30 days at a dose of 50 mg/kg.

Table 1 – Morphometric analysis of histological sections of non-linearalbinorats lung rats exposed to brucite

As can be seen from Table 1, under the influence of brucite, there was a sharp decrease in the surface area of the alveoli – by 19.1% – with 14-day administration, by 39.2% – with 30-day administration of the drilling reagent. This may indicate a possible emphysema of the lungs. The value of the average area of peribronchial infiltrates along the course of medium-caliber bronchi in the series of experiments is not significantly significant (p<0.05). The area of perivascular infiltrates exposed to inhalation administration of brucite for 14 days was increased by 1946.37 microns ² in comparison with the control. In the control group, this value is 17381 microns ² (p<0.05), in the experimental groups after 14 days and 30 days, it is 11% and 19% more, respectively. Changes on the part of the area of the alveolar space are characterized by the destruction of the alveoli, which in consequence unite with each other, forming one large cavity. The surface area of the alveoli decreases, which leads to a decrease in the intensity of oxygen and carbon dioxide exchange. As a result, the breathing of rats becomes more frequent and heavy (shortness of breath appears).

ConclusionSummarizing the results, it can be concluded that the inhalation of brucite leads to significant pathological changes in the lung structures of non-linearalbinorats rats.

At the same time, dystrophic processes are noted in the lungs, which are accompanied by the development of chronic inflammation, acute macrophage reaction, the formation of many airless areas alternating with emphysematous altered, the severity of which increases with the duration of the experiment. With the introduction of nanoparticles for 30 days, these violations are more intense.

The consequence of working with brusite of drilling company employees may be:

1) occupational, acute and chronic lung diseases;

2) specific sensitization of the body due to exposure to dust particles.

As a result of the study of patents of the Russian Federation (with registration numbers 2644097, 187423, 2538755, 2407567, 94421, 2180252, 2632654, 2632636, 173502, 195917, 2649373, 2640984, 2644316, 2631624, 2643427, 2677088, 188600, 90300, 2669747, 2642399, 137861, 143545, 32368, 40847, 131576, 135880, 2543462, 2664336, 2666464, 2697606, 2625928, 2678376, 2426484, 190961, 2651260, 2677714, 190600, 188199, 2652975, 2218199, 2297259, 2657886, 2401143, 2401144, 2399390, 2529829 2677082 2277838, 2175259, 2720696, 198762, 2729629, 198762, 198762, 2732699, 199561) for to reduce the negative impact of brucite on drilling workers, three personal protective equipment (PPE) were selected. Industrial tests have shown that the use of the selected PPE is not enough. In the future, it is planned to conduct a statistical analysis of morbidity rates with temporary disability, occupational diseases, and occupational poisoning of workers in contact with brucite and the development of effective measures to reduce the harmful effects of brucite on certain categories of drilling workers.

List of literatureGN 2.2.5.1313–03.

1. Maximum permissible concentrations (MPC) of harmful substances in the air of the working area.
2. GN 2.2.5.2308–08. Approximate safe exposure levels (levels) of harmful substances in the air of the working area.
3. GOST R 54578-2011 Working area air. Aerosols are predominantly fibrogenic. General principles of hygienic control and impact assessment.
4. MUC 4.1.2468-09 Measurement of mass concentrations of dust in the air of the working area of mining and non-metallic industry enterprises.
5. GOST R ISO 15767-2007. The air of the working area. Accuracy of weighing aerosol samples.
6. Kireev. I.R., Barakhnina V.B., Abdrakhmanov N.H., etc. Technosphere safety at oil and gas industry enterprises. Textbook under the general editorship of R.G. Sharafiev/N.H. Abdrakhmanov et al. – Ufa: Publishing house of USNTU, 2020. – 304 p.
7. Tagirova K.B., Gilyazov A.A., Barakhnina V.B. Comparative analysis of atmospheric pollution sources at an oil and gas enterprise. Ecological Bulletin of Russia, No. 6, 2020. – pp. 10-17.
8. Kireev I.R., Tagirova K.B., Barakhnina V.B. Determination of phytotoxicity of lignosulfonate drilling reagents ALS and PHLS. Ecological Bulletin of Russia, No. 3, 2020. – pp. 22-26.
9. Seifert D.V., Barakhnina V.B. Biodestruction of wasted drilling starch-based reagents and its modifications. Archives of Waste Management and Environmental Protection, vol. 16, Num. 3 (2014), – pp. 41-44.
10. Fattakhova E.Z., Barakhnina V.B. The effect of drilling additives on the health of workers of oil and gas producing enterprises. In: Proceedings of the 65th Scientific and Technical Conference of students, postgraduates and young scientists of USNTU. – Ufa: USNTU Publishing House. 2014. – pp. 283-284.
11. Mukhamadeeva A.I., Abdrakipov A.I., Barakhnina V.B. Toxic properties of polymer drilling additives. In the book: Materials of the XXV Anniversary International Scientific and Technical Conference "Chemical reagents, reagents and processes of low-tonnage chemistry", dedicated to the memory of Academician of the Academy of Sciences of the Republic of Belarus D.L. Rakhmankulov "Reagent-2011", – Ufa: Publishing House "Reagent", 2011. – pp. 203-205.
12. Abdrakhmanov N.H., Kireev I.R., Enikeeva T.M., Barakhnina V.B. Fundamentals of toxicology for oil and gas production specialists, – Ufa: Publishing House of USNTU, 2018. - 180 p.
13. Farrakhova A.T., Barakhnina V.B. Improving industrial and environmental safety at oil refining and petrochemical industry facilities. Ecological Bulletin of Russia. No. 3. 2016. – pp. 25-28.
14. . Shah, S. N., Shanker, N. H. and Ogugbue, C. C. Future challenges of drilling fluids and their rheological measurements, AADE fluids conference and exhibition, Houston, Texas, 5-7 April 2010.
15.  Bloys, B., Davis, N., Smolen, B., Bailey, L., Houwen, O., Reid, P. and Montrouge, F. Designing and managing drilling fluid, Oilfield Review, 6(2), (Accessed: 22 December 2014), – pp. 33-43.
16. Okpokwasili, G.C. Effects of drilling fluids on marine bacteria from a Nigerian offshore oilfield / G.C. Okpokwasili, C. Nnubia // Environ. Intern. – 1995. – Vol. 19, N 6. – pp. 923-929.
17. Wieczorek, D. Phytotests as tools for monitoring the bioremediation process of soil contaminated with diesel oil / D. Wieczorek, O. Marchut-Mikolajczyk, S. Bielecki // Biotechnol. Lett. – 2012. – Vol. 93, N 4. – pp. 431-439.
18. Candler, J.E. Synthetic-based mud systems offer environmental benefits over traditional mud systems / J.E. Candler, J.H. Rushing, A.J. Leuterman // Production Environmental Conference. San Antonio, 1993. – pp. 485-499.
19. Mcguire, T.C. Effects of surfactants on the dechlorination of chlorinated ethenes / T.C. Mcguire, J.B. Hughes // Environ. Toxicol. and Chem. – 2003. – Vol. 22, N 11. – pp. 131–140.
20. Lambert, R.J. Susceptibility testing: accurate and reproducible minimum inhibitory concentration (MIC) and non-inhibitory concentration (NIC) values / R.J. Lambert, J. Pearson // Microbiology. – 2000. – Vol. 88. – pp. 784-790.

Referenses1. GN 2.2.5.1313-03. Maximum permissible concentrations (MPC) of harmful substances in the air of the working area.

2. GN 2.2.5.2308-08. Approximate safe levels of exposure (s) to harmful substances in the air of the work area.

3. GOST R 54578-2011 the Air of the working area. Aerosols predominantly fibrogenic action. General principles of hygiene control and impact assessment.

4. MUC 4.1.2468-09 Measurement of mass concentrations of dust in the air of the working area of mining and non-metallic industry enterprises.

5. GOST R ISO 15767-2007. The air of the working area. Accuracy of weighing aerosol samples.

6. Kireev. I.R., Barakhnina V.B., Abdrakhmanov N.Kh. and other Technosphere safety at the enterprises of the oil and gas industry. Textbook. allowance under the general ed. R.G. Sharafieva / N.Kh. Abdrakhmanov and others - Ufa: USPTU Publishing House, 2020 .– 304 p.

7. Tagirova K. B., Gilyazov A. A., Barakhnina V. B. Comparative analysis of atmospheric pollution sources at an oil and gas enterprise. Ecological Bulletin of Russia, No. 6, 2020. – Pp. 10-17.

8. Kireev I. R., Tagirova K. B., Barakhnina V. B. determination of phytotoxicity of lignosulfonate drilling reagents ALS and FHLS. Ecological Bulletin of Russia, No. 3, 2020. – Pp. 22-26.

9. Seifert D. V., Barakhnina V. B. Biodestruction of wasted drilling starch-based reagents and its modifications. Archives of Waste Management and Environmental Protection, vol. 16, Num. 3 (2014), – p. 41-44.

10. Fattakhova E. Z., Barakhnina V. B. Influence of drilling additives on the health of employees of oil and gas production enterprises. In: Proceedings of the 65th scientific and technical conference of students, postgraduates and young scientists of usntu. – Ufa: usntu Publishing house. 2014. – pp. 283-284.

11. Mukhamadeeva A. I., Abdrakipov A. I., Barakhnina V. B. Toxic properties of polymer drilling additives. In the book: Proceedings of the XXV Jubilee International scientific and technical conference "Chemical reagents, reactants and processes of low tonnage chemistry", devoted to memory of academician of the Academy of Sciences RB D. L. Rakhmankulov "Reagent-2011", – Ufa: Izd-vo "Reagent", 2011. – pp. 203-205.

12. Abdrakhmanov N. H., Kireev I. R., Enikeeva T. M., Barakhnina V. B. Fundamentals of toxicology for oil and gas production specialists, – Ufa: USNTU publishing House, 2018. – 180 p.

13. farrakhova A. T., Barakhnina V. B. Improving industrial and environmental safety at oil refining and petrochemical industry facilities. Ecological Bulletin of Russia. No. 3. 2016. – pp. 25-28.

14. . Shah, S. N., Shanker, N. H. and Ogugbue, C. C. Future challenges of drilling fluids and their rheological measurements, AADE fluids conference and exhibition, Houston, Texas, 5-7 April 2010.

15. Bloys, B., Davis, N., Smolen, B., Bailey, L., Houwen, O., Reid, P. and Montrouge, F. Designing and managing drilling fluid, Oilfield Review, 6(2), (Accessed: 22 December 2014), – pp. 33-43.

16. Okpokwasili, G. C. Effects of drilling fluids on marine bacteria from a Nigerian offshore oilfield / G. C. Okpokwasili, C. Nnubia // Environ. Intern. – 1995. – Vol. 19, N 6. – pp. 923-929.

17. Vichorek, D. Phytotests as a tool for monitoring the process of bioremediation of soils contaminated with diesel fuel / D. Vichorek, O. Markhut-Mikolajchik, S. Beletsky // Biotechnology. Lett. – 2012. – Vol. 93, N 4. – pp. 431-439.

18. Candler, J. E. synthetic mud systems offer ecological advantages over traditional mud systems / J. E. Candler, J. H. Rushing, A. J. Leiterman // Industrial ecological conference. San Antonio, 1993. – pp. 485-499.

19. McGuire, T. S. the effect of surfactants on the dechlorination of chlorinated esters / T. S. McGuire, J. B. Hughes // environment. Toxicol. and chemical. – 2003. – Vol. 22, N 11. – pp. 131-140.

20. Lambert, R. J. Susceptibility testing: accurate and reproducible values of the minimum inhibitory concentration (Mic) and non-inhibitory concentration (nic) / R. J. Lambert, J. Pearson // Microbiology. – 2000. – Volume 88. – pp. 784-790.

BIOTESTING OF TOXIC EFFECTS OF DRILLING REAGENT BRUSITS ON DRILLING FACTORY WORKERSTagirova K. B., Barakhnin V. B., Fedosov A.V.

Ufa state petroleum technological University, Ufa

And bstract.

Many General-purpose inorganic chemicals are used in the technological processes of oil and gas well construction. The ingress of these reagents into the body of drilling workers along with inhaled air, food intake, through the pores and mucous membrane is currently not sufficiently studied. The effect of the brucit drilling reagent on the lung tissue of non-linearalbinorats rats was studied. When brucit was inhaled to rats, dystrophic processes were observed in their lungs, which were accompanied by the development of chronic inflammation and an acute macrophage reaction. There was a significant increase in the size of perivascular infiltrates compared to the control (13370±248.6 mm2^{) in the first series of experiments with 14 – day administration of brucite particles – 14867.21±369.29 mm}2 ^{in the second experiment, where the administration lasted for 30 days-15853.87±126.57. Morphometric analysis also showed a significant reduction in the area of the alveolar space and the area of the medium-sized bronchus. The lungs were marked by the formation of many airless areas, alternating with emphysematous-altered, the severity of which increased with the duration of exposure to the drilling reagent.}

Key words:, lungs, area of perivascular infiltrates, personal protective equipment, air pollution of the working area, harmful effects, alveoli, labor protection.