The article considers the influence of the regular microrelief on the leakage of fluid pumped through the plunger pair of sucker rod pump. To evaluate the effect of different types of regular microrelief on the amount of fluid leakage through the plunger pair and selecting the optimal type, in which liquid leakage is minimized, the following tasks were set: assessment of the influence of micro-relief plunger assembly by the amount of leakage; determining the optimal geometric parameters of the regular microrelief profile. The main factors influencing the leakage of liquid through the clearance of the plunger pair of the sucker rod pump during its operation are considered. Based on a comparative analysis of different shapes of grooves, a groove with a cross section in the form of a right triangle was examined. A simulation using computational fluid dynamics tools for fluid flow through the gap of the plunger pair with the groove, and the groove was in the form of a right triangle. Practical recommendations on the choice of geometrical parameters of grooves in which there is maximum hydraulic resistance for the flow of fluid in the gap plunger pair of sucker rod pump have been developed. The application of a regular microrelief on the plunger of a sucker rod pump in the form of grooves with a cross-section of a rectangular triangle provides an increase in the pressure drop of the fluid flow in the plunger gap, which allows to reduce the leakage of liquid. Computational simulation of fluid flow in the gap of the plunger pair has established the optimal geometric parameters of the grooves with the cross-section of a right-angled triangle, at which the maximum hydraulic resistance occurs

**References**

1. Urazakov K.R., Andreev V.V., Zhulaev V.P., Neftepromyslovoe oborudovanie dlya kustovykh skvazhin (Oilfield equipment for cluster wells), Moscow: Nedra Publ., 1999, 268 p.

2. Urazakov K.R., Zdol'nik S.E., Nagumanov M.M. et al., Spravochnik podobyche nefti (Handbook on oil production), St. Petersburg: Nedra Publ., 2012, 672 p.

3. Patent no. 2159867 RF, Installation for testing rod and screw oil-well pumps, Inventors: Urazakov K.R., Gabdrakhmanov N.Kh., Valeev M.D., AkhtyamovM.M., Galiullin T.S., Kutluyarov Yu.Kh., Makov I.A.

4. Patent no. 2193070 RF, Device for plastic working of parts cylindrical surfaces, Inventors: Ikonnikov I.I., Shtaygerval'd A.E., Urazakov K.R., Gazarov A.G.

5. Patent no. 2365786 RF, Oil well pump, Inventors: Bakhtizin R.N., Urazakov K.R., Ismagilov F.G., Agamalov G.B., Zhulaev V.P.

6. Ismagilov F.G., Uluchshenie tekhnicheskikh kharakteristik shtangovogo nasosa naneseniem regulyarnogo mikrorel'efa na poverkhnosti plunzhera (Improving the technical characteristics of the sucker pump by applying a regular microrelief on the plunger surface): thesis of candidate of technical science, Ufa, 2010.

7. Bakhtizin R.N., Ismagilov F.G., Gafurov O.G., The experimental research of deep-well working barrel element consider with micro relief on pump plunger surface (In Russ.), Neftegazovoe delo, 2008, V. 6, no. 2, pp. 33-40.

8. Nikitin G.A., Shchelevye i labirintnye uplotneniya gidroagregatov (Slotted and labyrinth seals of hydraulic units), Moscow: Mashinostroenie, 1982, 134 p.

9. Bakhtizin R.N., Urazakov K.R., Latypov B.M., Ishmukhametov B.Kh., Fluid leakage in a sucker-rod pump with regular micro-relief at surface of the plunger (In Russ.), Neftegazovoe delo, 2016, V. 14, no. 4, pp. 33-39.

10. Menter F.R., Kuntz M., Langtry R., Ten years of industrial experience with the SST turbulence model, In: Turbulence, Heat and Mass Transfer: edited by Hanjalic K., Nagano Y., Tummers M., Danbury: Begell House, Inc., 2003, pp. 625 – 632.

The article considers the influence of the regular microrelief on the leakage of fluid pumped through the plunger pair of sucker rod pump. To evaluate the effect of different types of regular microrelief on the amount of fluid leakage through the plunger pair and selecting the optimal type, in which liquid leakage is minimized, the following tasks were set: assessment of the influence of micro-relief plunger assembly by the amount of leakage; determining the optimal geometric parameters of the regular microrelief profile. The main factors influencing the leakage of liquid through the clearance of the plunger pair of the sucker rod pump during its operation are considered. Based on a comparative analysis of different shapes of grooves, a groove with a cross section in the form of a right triangle was examined. A simulation using computational fluid dynamics tools for fluid flow through the gap of the plunger pair with the groove, and the groove was in the form of a right triangle. Practical recommendations on the choice of geometrical parameters of grooves in which there is maximum hydraulic resistance for the flow of fluid in the gap plunger pair of sucker rod pump have been developed. The application of a regular microrelief on the plunger of a sucker rod pump in the form of grooves with a cross-section of a rectangular triangle provides an increase in the pressure drop of the fluid flow in the plunger gap, which allows to reduce the leakage of liquid. Computational simulation of fluid flow in the gap of the plunger pair has established the optimal geometric parameters of the grooves with the cross-section of a right-angled triangle, at which the maximum hydraulic resistance occurs

**References**

1. Urazakov K.R., Andreev V.V., Zhulaev V.P., Neftepromyslovoe oborudovanie dlya kustovykh skvazhin (Oilfield equipment for cluster wells), Moscow: Nedra Publ., 1999, 268 p.

2. Urazakov K.R., Zdol'nik S.E., Nagumanov M.M. et al., Spravochnik podobyche nefti (Handbook on oil production), St. Petersburg: Nedra Publ., 2012, 672 p.

3. Patent no. 2159867 RF, Installation for testing rod and screw oil-well pumps, Inventors: Urazakov K.R., Gabdrakhmanov N.Kh., Valeev M.D., AkhtyamovM.M., Galiullin T.S., Kutluyarov Yu.Kh., Makov I.A.

4. Patent no. 2193070 RF, Device for plastic working of parts cylindrical surfaces, Inventors: Ikonnikov I.I., Shtaygerval'd A.E., Urazakov K.R., Gazarov A.G.

5. Patent no. 2365786 RF, Oil well pump, Inventors: Bakhtizin R.N., Urazakov K.R., Ismagilov F.G., Agamalov G.B., Zhulaev V.P.

6. Ismagilov F.G., Uluchshenie tekhnicheskikh kharakteristik shtangovogo nasosa naneseniem regulyarnogo mikrorel'efa na poverkhnosti plunzhera (Improving the technical characteristics of the sucker pump by applying a regular microrelief on the plunger surface): thesis of candidate of technical science, Ufa, 2010.

7. Bakhtizin R.N., Ismagilov F.G., Gafurov O.G., The experimental research of deep-well working barrel element consider with micro relief on pump plunger surface (In Russ.), Neftegazovoe delo, 2008, V. 6, no. 2, pp. 33-40.

8. Nikitin G.A., Shchelevye i labirintnye uplotneniya gidroagregatov (Slotted and labyrinth seals of hydraulic units), Moscow: Mashinostroenie, 1982, 134 p.

9. Bakhtizin R.N., Urazakov K.R., Latypov B.M., Ishmukhametov B.Kh., Fluid leakage in a sucker-rod pump with regular micro-relief at surface of the plunger (In Russ.), Neftegazovoe delo, 2016, V. 14, no. 4, pp. 33-39.

10. Menter F.R., Kuntz M., Langtry R., Ten years of industrial experience with the SST turbulence model, In: Turbulence, Heat and Mass Transfer: edited by Hanjalic K., Nagano Y., Tummers M., Danbury: Begell House, Inc., 2003, pp. 625 – 632.