«Equipment and technologies for oil and gas complex»

RADIAL MECHANICAL SEAL IN SUCKER-ROD PUMPS

UDC: 622.276.53.054.22
DOI: 10.33285/1999-6934-2021-2(122)-15-18

Authors:

¹ LLC "Ecogermet-M", Moscow, Russian Federation
² Udmurt State University, Izhevsk, Russian Federation
³ LLC NPP "OSCON", Sarapul, Russian Federation

Keywords: sucker rod pump; plunger; leak; radial mechanical seal; friction; wear; volumetric efficiency; mean time before failure

Annotation:

A slotted seal of a plunger-cylinder pair in conditions of a sucker-rod pump operation is characterized by increased friction and wear, especially in complicated wells (increased and high viscosity of well products, wellbore curvature, mechanical impurities, etc.). All these factors contribute to a decrease of the pumping unit flow rate due to an increase in leaks and elastic deformations of the rod string, an increase in the amplitude of loads, in the length of the rod string zone subjected to alternating stresses, jamming of the plunger and breakage of the rod string. Therefore, problems related to seal leakages reduction and rods reliability improvement are of a paramount importance. To a large extent, this problem is solved by replacing the throat seal of the cylinder-plunger pair by a small-sized and efficient mechanical radial seal. On the basis of the specified mechanical seal, a number of new types of downhole sucker rod pumps (SRP) for oil production have been developed. The results of field tests and operation proved their main parameters advantages (flow rate coefficient and mean time before failure) in comparison with pumps with a slotted seal. A new design of the mechanical radial seal of SRP plungers is proposed, which allows not only to reduce leaks, but also to simplify its manufacture, assembly and repair. Further improvement and use of the mechanical seal is a certain reserve for increasing the profitability of oil production, especially from marginal wells and wells with complicated conditions.

Bibliography:

1. Насосная добыча высоковязкой нефти из наклонных и обводненных скважин / К.Р. Уразаков, Е.И. Богомольный, Ж.С. Сейтпагамбетов, А.Г. Газаров; под ред. М.Д. Валеева. – М.: Недра, 2003. – 303 с.
2. Захаров Б.С. Специальные типы штанговых насосов. – 2-е изд., перераб. – М.: ОАО "ВНИИОЭНГ", 2010. – 136 с.
3. Пат. 2037077 Рос. Федерация, МПК F16J 15/26. Механическое уплотнение / Б.С. Захаров. – № 93048995/29; заявл. 25.10.93; опубл. 09.06.1995.
4. Pat. № 5820130 USA, Int. Сl. F16J 15/38. Mechanical Seal for Movable Joints of Machines / B.S. Zakharov. – Appl. No. 632432; PCT Filed Feb. 16, 1994; Date of Patent Oct. 13, 1998.
5. Захаров Б.С. Поршневые и плунжерные насосы для добычи нефти: сб. ст. и пат. – М: ОАО "ВНИИОЭНГ", 2006. – 276 с.
6. Захаров Б.С., Драчук В.Р. Шариков Г.Н. Новое насосное оборудование для добычи нефти. – М.–Ижевск: Ин-т компьют. исслед., 2015. – 80 с.
7. Скважинные насосные установки для добычи нефти / В.Н. Ивановский, В.И. Дарищев, А.А. Сабиров [и др.]. – М.: Изд-во "Нефть и газ" РГУ нефти и газа им. И.М. Губкина, 2002. – 824 с.
8. Faisandier J., Reminiac B. Mechanisms hydrauliques. – Paris: Dunod, 1980. – XII, 207 p.
9. Драчук В.Р. Опыт эксплуатации дифференциальных штанговых насосов 2СПxx/xx // Оборудование и технологии для нефтегазового комплекса. – 2016. – № 6. – С. 27–32.