RU2320896C2 - Horizontal pumping unit - Google Patents

Abstract

FIELD: mechanical engineering; oil producing industry.

SUBSTANCE: invention relates to centrifugal pumps aimed at maintaining formation pressure at production of oil. Proposed horizontal pumping unit has support frame, electric motor, sectional centrifugal pump, suction unit, delivery unit, sealed thrust chamber filled with oil in which bearings are installed taking up radial and axial loads, and oil cooling system. Said oil cooling system has pipe with radiator placed in oil bath of thrust chamber and connected with suction unit, and impeller to circulate handled liquid in pipe fixed on shaft and arranged in suction unit separated from thrust chamber by end face seal.

EFFECT: increased operation reliability of horizontal pumping unit owing to provision of cooling of oil in thrust chamber by handled liquid, dispensing with cooling system and radiator with forced circulation of oil in thrust chamber.

3 dwg

Description

The invention relates to the field of mechanical engineering, in particular to the designs of centrifugal pumps used to maintain reservoir pressure in the oil industry during oil production.

Known horizontal pumping unit for injection into the reservoir of the process fluid used in the system for maintaining reservoir pressure. The installation comprises an electric motor, an input module and a horizontal centrifugal pump, coupled to the suction and discharge units, located on the support frame. The horizontal centrifugal pump is made sectional with the possibility of selecting stages to the required pressure. The first section of the pump is made combined with the node of the input module and is located with it on a common shaft, sealed on the motor side with a mechanical seal. A thrust unit is located in the input module assembly. The input module contains two additional radial bearings. Bearings rigidly fix the shaft in the radial direction and prevent its runout, and the elimination of unnecessary connecting elements increases the operational reliability and durability of the installation. [Source of information: patent for invention RU No. 2162163, cl. 7 F04D 13/06, 1999 (analogue)].

The disadvantage of this installation is that the input module, combined with the pump, does not allow for a quick replacement of the pump when it fails, and also to replace the mechanical seal during wear without dismantling the coupling and motor.

Known horizontal pumping unit, including an electric motor, a horizontal centrifugal pump, made sectional, and its first section is connected to the suction unit, and the last to the discharge unit. The suction unit is made in the form of a separate module with the ability to rotate 360 °. A thrust chamber is located between the suction unit and the electric motor, which receives the axial load from the pressure of the pumped liquid onto the shaft. The thrust chamber is made in the form of two oil-filled chambers with bearing supports. [Source: REDA Industrial Catalog (prototype)].

The disadvantage of the proposed installation is that constant cooling of the oil of the thrust chamber is necessary, a separate oil cooling unit is required, including an oil pump and forced cooling radiators.

The objective of the invention is to increase the operational reliability of a horizontal pumping unit by eliminating the cooling system and radiators with forced circulation of the oil of the thrust chamber, by cooling the oil bath of the thrust chamber with the pumped liquid.

This task is achieved in that a horizontal pumping unit containing a support frame, an electric motor, a centrifugal sectional pump, a suction unit, a discharge unit, a sealed oil-filled thrust chamber, in which bearings are installed that absorb radial and axial loads, according to the invention for an oil bath cooling system the pumped liquid is used in the thrust chamber, while the cooling system contains a pipe with the pumped liquid with a radiator, placed in the oil bath amers and connected to a suction unit, and an impeller placed on the shaft of the thrust chamber to the suction unit, separate from the thrust chamber and a mechanical seal fixed to the shaft during rotation creates circulation of pumped liquid in a cooling tube. The proposed horizontal pumping unit is illustrated by drawings, where:

figure 1 presents a lateral General view of a horizontal pumping unit;

figure 2. presents a longitudinal section of the thrust chamber;

figure 3 presents a longitudinal section of a centrifugal pump.

The horizontal pump installation consists (see Fig. 1) of a support frame 1, an electric motor 2 placed on it, a coupling 3, a thrust chamber 4 and a sectional centrifugal pump 5. The thrust chamber (see Fig. 2) consists of housings 6 and 14 installed in the caps 13 and 16, the mechanical seal 11 to eliminate the flow of suction fluid along the shaft 9, bearings 7 and 8 absorbing radial and axial loads from the input pressure of the pumped fluid and from the torque of the motor 2, pipe 10 with a radiator for cooling the oil These are β, impellers 17, a drain plug 15 for draining the used oil, suction assembly 12. The centrifugal pump (see FIG. 3) consists of one or several sections, each of which includes an input module 19, housing 23, the shaft 26 and the working steps 21 assembled on the shaft 26. The shaft 25 is fixed along the entire length of the assembly with radial bearings 20, 22, 24 and axial bearings 20, 25. The head of the pump section 27 is coupled to the discharge pipe 28.

Horizontal pumping unit operates as follows.

The torque from the electric motor 2 (see figure 1) to the thrust chamber 4 is transmitted by means of a coupling 3, for example, sleeve-finger type, then to the pump section 5, through the coupling 18 (see figure 3). The process fluid is piped or from a stationary tank through the suction connection unit 12 to the thrust chamber 4 of the horizontal pumping unit and then from the pump inlet module 19 (see Fig. 3) to the working stages 21, where the kinetic energy of the stream is converted into potential pressure energy and, having passed the stages of all pump sections, it acquires the necessary discharge pressure. And the axial load acting on the pump shaft 26 is perceived by the axial bearings, upper 25 and lower 20. Radial bearings 20, 22 and 24 located respectively in the lower, middle and upper part of the pump rigidly fix the shaft 26 in the radial direction, preventing runout. Bearings 7, 8 located in the thrust chamber (see figure 2) perceive axial and radial loads from the inlet pressure of the pumped liquid and from the torque of the electric motor 2, and the thermal energy generated in this case is accumulated in the oil bath β. The accumulated thermal energy of the oil bath β is discharged by a pipe 10 with a radiator connected to the pumped liquid of the suction unit 12, and the impeller 17, located in the thrust chamber 4 in the suction part of the centrifugal pump 5 behind the mechanical seal 11 and fixed on the shaft 9, creates a circulation of the pumped liquid during rotation in the cooling pipe 10.

The horizontal pumping unit will increase the pressure in the reservoir and increase oil recovery of the oil reservoir. Having selected the optimal operating mode of the horizontal pumping unit in terms of pressure and productivity, a large amount of oil can be extracted from the well. With the trouble-free operation of the horizontal pumping unit, the volume of oil production will increase. Cooling the oil bath of the intake chamber with the pumped liquid will increase the service life of the thrust chamber, increase the oil replacement period, increase the life of the horizontal pump installation, and reduce the cost of manufacturing a horizontal pump installation.

Claims (1)

A horizontal pump installation comprising a support frame, an electric motor, a sectional centrifugal pump, a suction assembly, a discharge assembly, a sealed oil-filled thrust chamber, in which bearings are installed that absorb radial and axial loads, and an oil cooling system, characterized in that the cooling system comprises a pipe with a radiator located in the oil bath of the thrust chamber and connected to the suction unit, and an impeller for circulating the pumped liquid in the pipe, fixed on the shaft and located in the suction unit, separated from the thrust chamber by a mechanical seal.

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