One of the problems of the oil and gas complex enterprises is the handling of equipment contaminated with sediments of natural radionuclides. Sources of radioactive contamination are those contained in the earth's crust and brought to the surface of planet as a result of oil production of natural radionuclides of the uranium and thorium series - thorium, radium and potassium-40, the main component of the deposits is radio barites. There is a need to clean radiation contaminated equipment for subsequent operation or environmentally friendly disposal.
The authors developed a technology for removing various deposits from the surfaces of oilfield equipment. Destruction of solid deposits is carried out by using the energy of the fluid flow supplied to the hydro-jet device — a pulsating cavitational flow of collapsing gas-vapor bubbles is generated, hydrodynamic force acting on salt deposits and high-amplitude vibrating microwave. The combined effect provides highly efficient cleaning at lower energy costs compared to conventional high-pressure cleaning. The amplitude-frequency and erosion characteristics of the jet flow are investigated. The substantiation of the profile of the internal channels of the nozzle-cavitators is made, the study of the optimal values of a number of technical and technological parameters of the cleaning process is carried out. A universal high-pressure apparatus was developed, manufactured and tested for the implementation of hydrodynamic cavitation cleaning of radiation-contaminated equipment. In carrying out the research methods of physical experiments, numerical simulation using software systems for hydrodynamics Star CCM+, ANSYS, FlowVision 2.3, analytical and numerical methods for solving problems were used.
There is positive experience in pilot studies and the introduction of equipment and technology for the decontamination and cleaning of tubing, working bodies of electric centrifugal pumps, in the fields of the Stavropol region and in Ukraine.
References
1. Priroda Rossii: Radiatsionnaya bezopasnost' neftegazovogo kompleksa (The nature of Russia: Radiation safety of the oil and gas complex), URL: http://www.priroda.ru/reviews/detail.php?ID=12065
2. Ryzhakov V.N., Krapivskiy E.N., Amosov D.A. et al., Efficient management of sites polluted with natural radionuclides during hydrocarbon production (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2002, no. 3, pp. 107–110.
3. Kulagin V.A., Metody i sredstva tekhnologicheskoy obrabotki mnogokomponentnykh sred s ispol'zovaniem effektov kavitatsii (Methods and means of technological processing of multicomponent media using cavitation effects): thesis of doctor of technical science, Krasnoyarsk, 2004.
4. Ganiev S.R., Issledovanie i razrabotka energosberegayushchikh tekhnologiy prigotovleniya i gomogenizatsii burovykh i tamponazhnykh rastvorov, osnovannykh na effektakh volnovoy mekhaniki (Research and development of energy-saving technologies for the preparation and homogenization of drilling and cement slurries based on the effects of wave mechanics): thesis of candidate of technical science, Moscow, 2010.
5. Omel'yanyuk M.V., Decontamination of oilfield equipment from natural radionuclides (In Russ.), Ekologiya i promyshlennost' Rossii, 2013, no. 2, pp. 1–9.
6. Omel'yanyuk M.V., Cleaning of oil-field equipment from saline deposits with natural radionucleids (In Russ.), Zashchita okruzhayushchey sredy v neftegazovom komplekse, 2008, no. 2, pp. 23-29.
7. Certificate of official registration of the database no. 2016621297, Database “Tekhnika i tekhnologii ochistki neftepromyslovogo oborudovaniya ot otlozheniy” (Technique and technology for cleaning oilfield equipment from deposits), Authors: Kazarov G.A., Alad'ev A.P., Omel'yanyuk M.V., Pakhlyan I.A.
8. Patent no. RU2676071C1, Device for cleaning internal surfaces, Inventors: Omel'yanyuk M.V., Pakhlyan I.A.
