RU2235906C2 - Oil-well sucker-rod pump-group hydraulic drive - Google Patents

Abstract

FIELD: oil producing industry.

SUBSTANCE: invention is designed for in group hydraulic drives of sucker-rod pumps in cluster wells. Proposed drive contains two power hydraulic single-acting cylinders for each pair of cluster wells, and hydraulic distributor. Plunger of hydraulic distributor is installed in housing with clearance to provide longitudinal displacement, and it forms chambers connected by supply channels with spaces of hydraulic cylinders and with oil pump. Pump sucker rods are connected with rods of hydraulic cylinders by chains laid over system of sprockets. One end of plunger is mechanically coupled with piston of one of hydraulic cylinders through compression springs, carriage and additional rod. Drive is furnished with metering oil pump.

EFFECT: improved operation reliability of drive, and its efficiency and simplified design.

2 dwg

Description

The invention relates to equipment for oil production, in particular to group hydraulic drives of sucker rod pumps used in wellbore wells.

A well-known group drive of sucker rod pumps, consisting of drive cylinders with pistons and rods, a power pump, controlled valves and valves, leakage compensation devices, balancing device and safety valve (1).

The disadvantages of the device include:

- the complex design of the drive, which includes a large number of hydraulic equipment and apparatus, manufactured with high accuracy;

- high operating costs due to frequent preventive examinations and the fact that servicing the drive requires the involvement of highly qualified specialists;

- poor operational reliability due to the large number of equipment included in the design and interconnected;

- unsatisfactory efficiency (efficiency) due to pressure losses during the passage of the working fluid through the numerous channels of the equipment.

The closest in technical essence to the proposed one is a group hydraulic drive of sucker rod pumps, containing two single-acting power cylinders with a piston and a rod for each pair of cluster wells, sucker rods with a polished rod, a hydrodistributing device including a casing connected to the supply channels with hydraulic cylinder cavities and main oil pump, storage tank and pressure reducing valve (2).

The main disadvantages of the device are:

- poor operational reliability due to the lack of the ability to compensate for leaks of the working fluid, which is necessarily present during operation of the device, which leads to disruption of its operation;

- low efficiency due to the use of jet nozzles having a low efficiency;

- the complexity of the design, due to the presence of mechanisms for regulating nozzles of jet nozzles.

The objective of the invention is to provide a drive with a relatively high operational reliability, high efficiency and simplified design.

This problem is solved by the proposed group hydraulic drive of a sucker rod pump, containing two single-acting power cylinders with a piston and a rod for each pair of cluster wells, sucker rods with a polished rod, a hydraulic distribution device that includes a housing connected to the inlet channels with hydraulic cylinder cavities and the main oil pump, an accumulative capacity and pressure reducing valve.

New is that power hydraulic cylinders are located perpendicular to the axes of the wells, and their rods are connected to polished rods of pump rods by chains enveloping the sprockets, the upper of which are installed above the upper position of the polished rods, and the lower ones with the possibility of alignment of the chains and rods of power hydraulic cylinders ; the hydrodistributing device is equipped with a two-stage plunger installed in the housing, each stage of which consists of a cylindrical section with sections attached to it on both sides in the form of truncated cones directed by small bases in opposite directions; the steps of the plunger are rigidly interconnected and installed inside the housing with a gap that allows longitudinal movement and form chambers with it that are identical in shape to the profile of the plunger in diameter and the length of its steps, and the chambers located in the area of the cylindrical sections are communicated by supply channels with power cavities hydraulic cylinders, and the chamber between the steps and the chamber outside the steps with the main oil pump; opposite end conical sections of the plunger are provided with guides, one of which is kinematically connected through compression springs and the carriage with an additional rod connected to the piston of one of the power hydraulic cylinders; equipped with a dosing oil pump, the discharge line of which is connected through a non-return valve to the line of the main oil pump, and through a pressure reducing valve to a storage tank.

Figure 1 shows a schematic diagram of the design of the proposed drive;

figure 2 is a longitudinal section of a hydraulic distribution device.

The proposed drive consists (Fig. 1) of power hydraulic cylinders 1 and 2 with pistons 3 and 4 and rods 5 and 6 installed near the wells 7 and 8 perpendicular to their axis. The rods of hydraulic cylinders 5 and 6 are connected by chains 9 and 10, thrown through sprockets 11, 12, 13 and 14 with polished rods 15 and 16, which in turn are connected to columns of pump rods (not shown). The upper sprockets 12 and 14 are installed above the upper position of the polished rods, and the lower 11 and 13 - with the possibility of ensuring alignment of the chains and rods of the hydraulic cylinders.

The drive also contains a hydraulic distribution device 17 connected by supply channels to the main oil pump 18.

The hydraulic distribution device 17 (Fig. 2) includes a housing 19 in which a two-stage plunger 20 is installed, each stage of which consists of a cylindrical section 21 and conical sections 22. The plunger 20 is installed inside the housing with a gap and forms chambers with it identical in shape the profile of the plunger in diameter and the length of its steps. The steps of the plunger are interconnected rigidly, and their opposite end conical sections are provided with guides 23 and 24, the first 23 of which are provided with shoulders 25 and 26 (Fig. 1) with compression springs 27 and 28 and kinematically connected with the carriage 29, which is connected in turn with a rod 30 connected by a piston 3 of the hydraulic cylinder 1.

The chambers of the hydraulic distribution device “b” and “g” (Fig. 2) located in the area of the cylindrical sections are connected by pipelines 31 and 32 to the cavities of the hydraulic cylinders 1 and 2, the chamber “a” and the chambers “k” and “n” by the pipelines 33, 34 and 35 with the oil pump 18. The device 17 is equipped with seals 36 and 37. The drive is equipped with a metering oil pump 38 (Fig. 1), the discharge line 39 of which is connected through the check valve 40 to the suction line of the main oil pump 18, and through the pressure reducing valve 41 to the storage capacity 42.

The operation of the drive is carried out in the following sequence.

The oil pump 18 pumps the working fluid through the pipe 33 into the cavity “a” of the device 17, from where it enters the cavity “b” through the gap between the housing and the plunger and from there goes through the pipe 31 to the cavity “c” of the hydraulic cylinder 2. At the same time, from the cavity “g” hydraulic cylinder 1, the working fluid under the influence of the mass of the string of pump rods through the pipe 32 (under pressure) is sent to the cavity "g", and then to the cavity "n", from which through the pipe 34 it enters the suction line of the oil pump 18. As a result, the column is lifted pump x 8 rods downhole by the length of the polished rod and, accordingly, liquid raising and lowering of the rod string 7 in the borehole.

From the moment when the carriage 29 touches the left compression spring 28, the latter begins to compress and this continues until its elastic forces overcome the resistance forces from the “n” side. After that, the plunger 20 moves to the left and takes a position at which the working fluid from the cavity “a” enters the cavity “g” and from there through the pipe 32 into the cavity “g” of the hydraulic cylinder 1. At the same time, from the cavity “c” of the hydraulic cylinder 2 the pipeline 31 is sent to the cavity “b”, and from there to the cavity “k” and further along the pipe 35 to the suction line of the oil pump 18. In the future, the cycle repeats.

During operation of the drive, there are leaks of the working fluid in the hydraulic cylinder system, the hydraulic distribution device and the supply line. Compensation of leaks from the system is carried out using a metering oil pump 38, which pumps the working fluid into the suction line of the oil pump 18 when the pressure in it becomes less than the pressure created by the mass of the rod string. Up to this point, the working fluid passing through the pressure reducing valve 41 is discharged into the storage tank 42.

The introduction to the design of the drive of the device for compensating for leaks and the hydraulic control device, which provides low pressure losses, increase its operational reliability. The efficiency is also increased due to the fact that the sealing surfaces between the housing and the plunger in the hydraulic distribution device are conical, and the supply channels have smooth transitions.

Information used

1. A.S. No. 1174594, MKI 4 F 04 B 47/00, 1985 (analogue).

2. A.S. No. 1286810, MKI 4 F 04 B 47/00, 47/04, 1987 (prototype).

Claims (1)

A group hydraulic drive of a borehole sucker rod pump, containing two single-acting power cylinders with a piston and a rod for each pair of wellbores, pump rods with a polished rod, a hydraulic distribution device including a housing connected by supply channels to the power cylinder cavities and the main oil pump, a storage tank and a reduction a valve, characterized in that the power cylinders are perpendicular to the axes of the wells, and their rods are connected to polished rods and sucker rods by means of chains enveloping the sprockets, the upper of which are installed above the upper position of the polished rods, and the lower ones with the possibility of ensuring alignment of the chains and rods of the power hydraulic cylinders; the hydrodistributing device is equipped with a two-stage plunger installed in the housing, each stage of which consists of a cylindrical section with sections attached to it on both sides in the form of truncated cones directed by small bases in opposite directions; the steps of the plunger are rigidly interconnected and installed inside the housing with a gap that allows longitudinal movement and form chambers with it that are identical in shape to the profile of the plunger in diameter and the length of its steps, and the chambers located in the area of the cylindrical sections are communicated by supply channels with power cavities hydraulic cylinders, and the chamber between the steps and the chamber outside the steps with the main oil pump; opposite end conical sections of the plunger are provided with guides, one of which is kinematically connected via compression springs and the carriage with an additional rod connected to the piston of one of the power hydraulic cylinders, while the drive is equipped with a metering oil pump, the discharge line of which is connected through the check valve to the suction line of the main oil pump, and through a pressure reducing valve - with a storage tank.

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