Interpretation of the processes occurring during the removal of wax deposits in the oil well by the heat transfer media can be based only on the distribution of temperature fields that take into account the temperature variations in the flow and on the inner surface of the oil well tubing. Taking into account the experience of carrying out flushing with the heat transfer media in oil wells of the Perm region, distributions of temperature in oil wells tubing and wax deposits melting have been obtained, depending on the depth of wax deposits formation. A model for the distribution of temperature fields reflecting the stages of the process of dewaxing the well with the fluid heating medium is constructed.
The process of wax deposits removal during flushing with the heat transfer media in oil wells is a completely physical process. Effective wax deposits removal with the use of water-based heat transfer media can be achieved by adding chemical reagents (additives) that have the desired properties at a temperature between 20 and 90° C, but to determine the temperature regime and the concentration of chemical reagents (efficiency determination) it is necessary to investigate detergency effectiveness.
The article describes the detergency effectiveness of four chemical reagents of well-known Russian producers, as well as fresh water for 14 oil wells in the Perm region. When determining the detergency effectiveness of reagents wax deposits removal the wax deposits composition should be taken into account. The detergency effectiveness of the reagents for wax deposits removal was determined for each type of wax deposits at heat transfer media temperatures of 50, 60 and 70 °C. At the heat transfer media temperature of 50 °C, the detergency effectiveness of fresh water with chemical reagents (additives) was absent.
Based on the studies carried out, the following conclusions can be drawn: for an oil well, it is necessary to sel ect an individual chemical reagent, taking into account the wax deposits composition; flushing efficiency in the wells of oil fields of the Perm region for the purpose of wax deposits removal is maximal at the heat transfer media temperature on the whole area of formation not less than 70 °С, for light oil fields – not less than 60 °С.
References
1. Tronov V.P., Mekhanizm obrazovaniya smolo-parafinovykh otlozheniy (Mechanism of formation of resin-paraffin deposits), Moscow: Nedra Publ., 1970, 192 p.
2. Ibragimov N.G., Khafizov A.R., Shaydakov V.V. et al., Oslozhneniya v neftedobyche (Complications in oil production): edited by Ibragimov N.G., Ishemguzhin E.I., Ufa: Monografiya Publ., 2003, 302 p.
3. Mordvinov V.A., Turbakov M.S., Erofeev A.A., The estimation technique of depth of intensive formation of paraffin sediments on downhole equipment (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 7, pp. 112–115.
4. Turbakov M.S., Obosnovanie i vybor tekhnologiy preduprezhdeniya i udaleniya asfal’tenosmoloparafinovykh otlozheniy v skvazhinakh (na primere neftyanykh mestorozhdeniy Permskogo Prikam’ya) (Choice of technology for prevention and removal of asphalt, resin, and paraffin deposits in wells (on the example of oil deposits of Perm Kama region)): thesis of candidate of technical science, St. Petersburg, 2011.
5. Turbakov M.S., Ryabokon’ E.P., Cleaning efficiency upgrade of oil pipeline from wax deposition (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2015, V. 14, no. 17, pp. 54–62. DOI: 10.15593/2224-9923/2015.17.67
6. Mordvinov V.A., Turbakov M.S., Lekomtsev A.V., Sergeeva L.V., The effectiveness of measures to prevent the formation and removal of asphaltene deposits in the operation of oil wells in the LUKOIL-PERM LLC (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, 2008, no. 8, pp. 78–79.
7. Turbakov M.S., Chernyshov S.E., Ust'kachkintsev E.N., Efficiency analysis of technologies for prevention the formation of asphaltene tar wax-bearing deposits on the mines of Perm Prikamy (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 11, pp. 122–123.
8. Ust'kachkintsev E.N., Melekhin S.V., Determination of the efficiency of wax deposition prevention methods (In Russ.), Vestnik Permskogo natsional'nogo issledovatel'skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2016, V. 15, no. 18, pp. 61–70, DOI: 10.15593/2224-9923/2016.18.7
9. Turbakov M.S., Erofeev A.A., Results of estimation of thermodynamic conditions of sediments formation of asphatlene-resin-paraffin materials in wells of the Sibirskoye oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 11, pp. 106–107.
10. Lekomtsev A.V., Turbakov M.S., Mordvinov V.A., Assessment of intensive paraffin accumulation depth in wells of Nozhovsky group oilfields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2011, no. 10, pp. 32–34.
11. Safin S.G., Development of compositions for removal of asphalt-resin-wax depositions in the oil-field equipment (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2004, no. 7, pp. 106–109.
12. Sharifullin A.V., Nagimov N.M., Kozin V.G., Hydrocarbon composites for the removal of asphaltene-resin-paraffin deposits (In Russ.), Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdeniy, no. 2002, no. 1, pp. 51–57.
13. Zlobin A.A., Experimental research of nanoparticle aggregation and self-assembly in oil dispersed systems (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2015, V. 14, no. 15, pp. 57–72, DOI: 10.15593/2224-9923/2015.15.7.
14. Zlobin A.A. Study of mechanism of oil magnetic activation in order to protect production wells fr om wax deposition (In Russ.), Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Geologiya. Neftegazovoe i gornoe delo = Perm Journal of Petroleum and Mining Engineering, 2017, V. 16, no. 1, pp. 49–63, DOI: 10.15593/2224-9923/2017.1.6.
