RU2312253C2 - Modular section of submersible centrifugal electric pump - Google Patents

Abstract

FIELD: oil producing industry.

SUBSTANCE: invention can be used in submersible centrifugal pumps for recovery of formation fluid (oil) from well. Proposed modular section of pump contains perforated housing with multisection slot filter element including outer rings, and shaft installed in housing by means of intermediate bearing. Additional intermediate bearings are installed in inner space of modular section, being separated from one another by equal-size perforated tubes. Intermediate bearings are furnished with baffles and baffle spring loading members arranged in pairs in each intermediate bearing. Perforated housing and filter element are braced from top by upper head accommodating upper bearing, and from bottom, by lower base with protective bushing on splined sleeve. End faces of ends of slot filter element sections are concealed in slots of outer rings.

EFFECT: reduced wear of support, vibration of plant and elimination of zones of stagnation.

2 cl, 1 dwg

Description

The invention relates to a pump engineering and can be used in submersible centrifugal electric pumps for the production of formation fluid (oil) from wells.

A well-known input module of a submersible centrifugal electric pump for lifting liquid from wells, the base of which is equipped with a self-cleaning multi-section filter (RU No. 42081 U2). The above input module of a submersible centrifugal pump can be taken as an analog.

The design drawback is the rapid wear of the support installed in the hydroprotection, due to its vulnerability to fine-grained sludge settling into the cavity together with a gas-liquid emulsion after filtering it with a slit filter element due to gravity. Due to wear of the support and internal friction surfaces, significant vibration and cavitation processes occur, leading to the failure of the submersible centrifugal electric pump. The presence of a gap between the end face of the slit screen and the outer ring leads to the penetration of sludge into the module. The presence in the upper part of the working apparatus leads to the appearance of stagnant zones in which fine-grained sludge is deposited due to cavitation processes.

The objective of the invention is to reduce the wear of the support, reducing the vibration of the installation and the elimination of stagnant zones.

The proposed modular section of a submersible centrifugal pump contains a perforated housing, on top of which there is a slotted screen. Each part of the slit screen is separated by rings, which have a hollow inside the cavity to hide the end ends of the slit screen. The perforated housing and the slit screen are limited by a screed from above - the upper head with the upper bearing, and from the bottom - the lower base with a protective sleeve on the spline coupling.

To achieve a technical result according to the invention, additional intermediate bearings are installed in the internal cavity of the modular section, which are separated from each other by equal-sized perforated tubes. To remove focal vibration, the bearings are equipped with chippers and spring elements of chippers, which are placed in pairs in each intermediate bearing. The spring element is a steel spring bounded on top by an intermediate bearing bump, and below by a sleeve. The perforated housing and the filter element are pulled together by the upper head with the upper bearing placed in it, and by the lower base from the bottom with the protective sleeve placed on it on the spline coupling. The ends of the ends of the slit filter element sections are hidden in the grooves of the outer rings. The shape and number of holes of the perforated tubes and the housing of the modular section are calculated depending on the hydraulic resistance of the gas-liquid emulsion passing through it, the gas factor, and the gas saturation of the medium.

The operation of the device is illustrated by the links to the attached drawing. The drawing shows a modular section. The modular section is a shaft 1 with bearings 3 mounted on protective sleeves 2 at regular intervals with spring loaded bumpers 4, limited by support sleeves 5. Perforated spacer tubes 6 are located between the bearings 3. The perforated housing 7 and the slotted filter element 8 are pulled together by the head 11 with the upper bearing 12 , a protective sleeve 13, a spacer sleeve 14 and a base 15. Each section of the slotted filter element is separated by outer rings 9 with grooves 10.

The process is as follows.

An inhomogeneous, layered gas-liquid emulsion, rising along the wellbore, enters the modular section according to the drawing. Having passed through the slotted filter element 8, it is cleaned of large particles of mechanical impurities by partial grinding on the sharp edges of the filter element 8 to a suspension state. An inhomogeneous gas-liquid emulsion enters the internal cavity of the modular section. Part of the gas-liquid emulsion continues linear upward movement, part, being guided by the rotating shaft 1, goes into a turbulent upward movement. The shaft 1 is separated by protective sleeves at the places where the friction parts touch. 13. To install and fix the slotted filter element 8 on the module body, a system of perforated tubing 6 is used, closed from above with a perforated housing 7 above which the slotted filter element is located 8. Gas-liquid emulsion passing through the internal cavity module, gets into the gas separator and at the pump intake.

Claims (2)

1. The modular section of a submersible centrifugal electric pump containing a perforated housing with a multi-section slotted filter element located on it, including outer rings, and a shaft mounted in the housing by means of an intermediate bearing, characterized in that additional intermediate bearings are installed in the internal cavity of the modular section, which are separated from each other each other with equal sized perforated tubes, the bearings are equipped with chippers and spring elements of chippers, which are in pairs in each intermediate bearing, and the perforated housing and the filter element are pulled together by the upper head with the upper bearing placed in it, and by the lower base from the bottom with the protective sleeve placed on it in the spline coupling, while the ends of the ends of the slit filter element are hidden in the grooves of the outer rings . 2. The modular section according to claim 1, characterized in that the spring element of the chippers is a steel spring bounded above by a chipper of an intermediate bearing, and below by a sleeve.

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