RU168390U1 - Linear rack drive sucker rod pump for oil production - Google Patents

Abstract

The linear rack-and-pinion drive of a sucker rod pump for oil production, contains a cylindrical rail with a through hole or an open channel, a support bearing assembly for hanging rods or a rod rotator. The cylindrical shape of the rail is the easiest to manufacture, since the guides are formed by one surface, this form is easiest to put into practice. The support bearing assembly or rod rotator eliminates the transmission of torque that occurs during operation from the pump and rods in the well to the rail, which eliminates the need for additional guides for fixing the rail in a radial direction relative to its axis. The shape of the through channel is selected in accordance with the technological capabilities of production.

Description

The field of technology.

The inventive utility model relates to the field of petroleum engineering, and in particular to pumping systems for oil production using the installation of sucker rod pumps (USGN).

The level of technology.

In world practice, the most widespread pumping systems for oil production from low and medium production wells are the installation of deep sucker rod pumps (USGN). Common features of these installations are as follows:

1) The working body of the pumping system is a deep-well pump of a volumetric type that performs linear reciprocating motion, among which the most common plunger pumps. These pumps are located directly in the oil well.

2) Transmission based on a rod column (suspension) with a wellhead (polished) rod located in its upper part. It links the surface drive to the submersible pumps. With its help, the mechanical energy necessary for linear reciprocating motion is transmitted to the pump.

3) A surface drive (electromechanical converter) with which electrical energy is converted into mechanical energy of a linear reciprocating motion. This energy is transmitted through a rod suspension to a deep rod pump (SHG) to perform work on lifting the formation fluid from the well.

4) A control system (SU) with the help of which the operation of the pump unit is controlled, and the latter is protected from emergency situations.

The most traditional types of surface drive USHGN are rocking balancing machines (SK). With their high durability, reliability and maintainability, this type of drive has significant disadvantages. The main ones are the need to build a massive foundation under them and the suboptimal law of motion of the output link associated with the rod column [see 1 - V.N. Ivanovsky “Increasing interest in sucker rod pumping units” - “NEFTEGAZ Territory” No. 8, August 2013, p. 46-47]. The truly sinusoidal law of motion of the USHGN transmission with the SC leads to the appearance of large voltages in the transmission of the USHGN, which reduces the reliability of both the rod string and the plunger-type deep-well rod pump. - [cm. 2 - Galimullin M.L. "Development of technical means to increase the efficiency of borehole plunger pumps" - Abstract for the degree of candidate of technical sciences - Ufa, 2004, 25 pp.]

The optimization of the law of motion of the output drive unit (maintaining a constant speed over the entire length of the working stroke) was achieved in other types of drive USHGN. This is, first of all, a chain drive (CPU) for USGN [see 3. - Valovsky V.M., Valovsky K.V. “Chain drives of borehole sucker rod pumps” - JSC VNIIOENG, Moscow, 2004, 492 pp.], And a hydraulic drive (GP) for UShGN [see 4 - A. Drozdov “Hydraulic drive pumps for complicated conditions” - Oil and gas vertical - No. 11, 2010, p. 38-42]. However, due to the complexity of the kinematic scheme for converting the rotational motion of the electric motor into linear reciprocating motion of the rod string, the chain drive is significantly inferior in reliability to the rocking machine [see 1 - V.N. Ivanovsky “Increasing interest in sucker rod pumping units” - “NEFTEGAZ Territory” No. 8, August 2013, p. 46-47]. In addition, a massive foundation is also required for its installation in the well. And the hydraulic drive, although it allows you to provide the most optimal characteristics for operation, is also a very complex system, the disadvantages of which are especially pronounced during operation in operating conditions at low ambient temperatures.

The above disadvantages led to the creation of a linear electromechanical drive USHGN based on rack and pinion, which are proposed to be called "linear rack drive USHGN" [see 1 - V.N. Ivanovsky “Increasing interest in sucker rod pumping units” - “NEFTEGAZ Territory” No. 8, August 2013, p. 46-47]. This type of drive is currently patented and manufactured by Unico. Inc (USA) under the brand name LRP, successfully introduced in the oil fields of the world.

The closest technical solution in its essence and the achieved effect to the claimed device of the utility model is patented by Unico. Inc (USA) invention "The device of a linear sucker rod pump and method of its operation" [see 5 - US Patent No. US 8152492 B2, MCP F04B 17/00, publ. 04/10/2012, Prior. June 12, 2006]. Let us dwell on the features of the prototype, which according to its distinctive features is a drive device USHN its SU and a way to control this device. The patent formula of the prototype describes a linear sucker rod pump system providing a reciprocating vertical movement of the sucker rod sucker rod string column (SHG), the device contains:

Linear mechanical drive, consisting of:

- from the housing mounted on the flange of the column head;

- a vertically located movable element associated with the rod column USHGN, with the help of which a controlled reciprocating vertical movement of the rod column of the deep pump is provided;

- a reversible engine having a reversibly rotating element operably connected to a vertically movable element.

Interaction in a linear mechanical drive is carried out in such a way as to provide a fixed relationship between the angular position of the rotating element of the electric motor and the movement of a vertically movable element, reversible with the possibility of a turn (reverse). The engine alternately rotates first in the forward direction at the first part of the pump stroke (stage upward stroke of the plunger), and then in the opposite direction during the second part of the pump stroke (stage downward stroke of the plunger);

The linear mechanical drive device includes a rack and pinion gear, consisting of a rack with a gear rack formed on it and a pinion gear, adapted to work in the vertical direction to provide reciprocating movement of the rack along the axis of the pump stroke. The rack of the rack is functionally connected to the ring gear of the drive gear, and this gear is functionally connected to the rotating shaft of the engine. Thus, the rotation of the electric motor in the forward direction ensures the movement of the rack of the gear rack vertically up along the axis of the pump stroke, and the movement of the rack of the rack vertically down is accompanied by rotation of the motor in the opposite direction, opposite the forward direction of the pump. The rack of the rack is functionally connected to the wellhead of the rod string for transmitting force. The stand has at its upper end a device (assembly) for quick attachment of the rod string rod. The rack has a longitudinally directed hole extending along the axis of the pump stroke from the lower end of the rack to the upper part of the rack. The rod has the ability to move inside the rack in the hole. The linear mechanical drive device further comprising a mounting clip (latch), which provides a rigid mount rod rod to the column. The mounting clamp (latch) provides support and transmits force to the upper end of the rod string from the rack rack drive.

The rack of the rack drive having a U-shaped cross section forming a longitudinally directed hole in the rack, in the form of an open channel located around the axis of the pump stroke, and from the outer surface of the central part of the rack, directed opposite from the legs, there are teeth for engagement with the corresponding teeth crown gear;

The linear sucker rod pump device also has one or more guideway roller bearings. They are placed longitudinally against the legs of the rack and opposite the gear, to ensure the engagement of the teeth of the rack rack and pinion mechanism with the ring gear of the pinion gear;

The device of a linear sucker rod pump has a pair of guide bearings placed on the sides of the legs of the rack, opposite each other, to force hold the rack in a position that ensures engagement of the teeth of the rack with the crown of the pinion gear.

Additional patent claims disclose the following:

Claims 2 and 3 of the patent claims reveal design features of the location of the pinion gear in a linear mechanical drive.

In paragraph 4 of the patent claims, it is reported that the device may further comprise a mechanical gearbox (box) located between the electric motor and the pinion gear.

In paragraph 5 of the patent formula, it is reported that the mechanical gearbox used in claim 4 is a bevel gearbox, so that the axis of rotation of the pinion gear is perpendicular to the axis of the pump stroke.

6, the patent claims discloses the features of a control system (CS) with a linear rack-and-pinion drive of a pump installation, which ensures the operation of the electric motor in the "motor" mode when the rack moves upward (direct rotation of the electric motor) with the ascending part of the pump stroke; and ensures the operation of the engine in braking mode (the electric motor operates in the "generator" mode), when the rack moves downward with the descending part of the pump stroke. In addition, the control system includes an energy storage element for storing energy generated in the braking mode of the electric motor (when the electric motor is in the generator mode), in which there is a unit for using the stored energy, which provides the accumulated energy to the electric motor while the electric motor is operating in motor (loaded) mode. The control system may also include a scattering element to ensure dispersion of the energy generated by the electric motor in the mode of braking its operation, while the control device is selectively configured to operate one or the other of the energy storage elements and the energy dissipation element.

Claims 7, 8 and 9 of the patent claims disclose that the device further comprises an oil pan (bathtub, crankcase) located below the lower end of the strut and configured to hold the amount of lubricant in it and to immerse the lower end parts of the rack, resulting in lubrication of the rack during its working movement. The bottom of the rack is immersed in the grease located in the pan during at least part of each pump stroke. The pan (bathtub, crankcase) is formed by two pipes hermetically connected at the bottom, forming a liquid annular cavity between them, to fill the volume of lubricant that is pumped into the upper part of this annular cavity into this cavity. The inner tubular wall of the sump is located around the wellhead, and fits freely inside the opening of the rail to provide travel, and the outer wall of the tubular sump is located around the rail.

10 and 11, the claims indicate that the device may further comprise an elastic element located inside the cavity in the sump, below the lower end of the rack. It provides the appearance in the system of an upward directed force applied to the lower end of the rack, if the lower end of the rack has gone beyond the permitted normal lower position of the rack during the course of the working stroke. The elastic element can also be configured to form an upward force exerted on the lower end of the strut during part of each working stroke of the submersible sucker rod pump. According to the description of the invention, the elastic element can be made in the form of a pneumatic cylinder, in which air is compressed during the strut downward, and expands during the strut upward. The latter allows you to use the energy released at the stage of progress of the SHG down, for use when working at the stage of the progress of SHG up.

The technical solution chosen as a prototype has excellent qualities that allows for flexible optimal working cycle with the ability to separately control the speed of the rod string (and therefore the plunger) of the pump at any stage, including the possibility of introducing a waiting stage between the stages "And" move down. " In addition, to use such devices there is no need to use massive capital foundations at the wellhead. The entire drive is directly attached to the casing flange.

The disadvantage of the technical solution chosen as a prototype is that in this design the guide rails are formed by four flat surfaces, the manufacture of which with a given accuracy is a complex and time-consuming task both in the housing and on the rail itself, and requiring clearance adjustment mechanisms.

Disclosure of the proposed technical solution.

The purpose of the claimed utility model is to simplify the design of the rack assembly and expand operational capabilities.

This goal is achieved due to the fact that in the known device of a linear rack-and-pinion drive of a deep rod pump, consisting of the following components:

- an electric drive unit, an electric motor (4) with a gearbox (5) located on its shaft or a gear motor (formed in a single electric motor housing and connected to a bevel gear);

- rack gear (mechanism), consisting of a gear rack (8), adapted to work in the vertical direction to provide reciprocating movement of the rack along the axis of the pump stroke, and the pinion gear of the rack gear (11) with the axis perpendicular to the axis of the pump stroke, functionally connected to the output element of the electric drive unit;

- the attachment site of the wellhead rod of the rod string (10) (polished rod supports);

- guides (12) located in the housing above and below the gear, for fixing and direction of the rack in the position that engages the teeth of the rack with the crown of the pinion gear;

The device may further comprise the following elements:

- a pallet (crankcase) with grease, which provides lubrication to the rack mechanism by immersing the bottom of the rail into it,

- an elastic element (9) designed to support the rail in the lower position during stops, repairs, and to prevent it from exceeding the working range in the event of equipment failure, it can also be configured to form an upward force applied to the lower end of the staff during the move to the top.

The rack rack has a rounded section in the form of a segment of a circle, and the teeth of the rack and pinion are formed in the region of the chord of the segment.

The rod suspension relies on the bearing assembly, while excluding the torque arising during operation from the pump and rods, which eliminates the need to fix the rack in the radial direction relative to its axis. The support bearing assembly can be located in the rail from above from below and anywhere on its body.

Also in the rail there may be an open channel through its length, the axis of which is parallel to the axis of the working stroke of the deep-well pump, the channel is placed opposite the teeth of the rack and is designed to accommodate a polished rod in it.

Options for the cross-sectional shape of the through open channel can be as follows:

1) round shape (Fig. 5);

2) a rectangular shape having a connection with the outer circular surface of the rack;

3) a combination of two merging figures of a circle and a rectangle (Fig. 6, Fig. 7).

The device may include an electric or mechanical rod rotator designed for forced rotation of the rods. Which is mounted on a bearing support.

The main difference of the proposed technical solution from the prototype is that instead of the U-shaped (U-shaped) section, the rack has a rounded section. In fact, it can be made of a solid metal circular profile by carrying out turning, milling and drilling operations. This design is the easiest to manufacture, since the guides are formed by one cylindrical surface, this form is easiest to put into practice. While in the prototype of Unico Inc. (USA) guide surfaces of at least four.

There is also a support bearing assembly, which eliminates the torque that occurs when the pump is operating from rods in the well, which eliminates the need for additional guides to fix the rack in a radial direction relative to its axis.

On its basis, a linear rack-and-pinion drive USHGN with a lifting capacity of 12 tons with a stroke length of 3 m was designed.

The essence of the utility model is illustrated by drawings.

Description of drawings

In FIG. 1, FIG. 2, FIG. 3 and FIG. 4 presents a General view and section of a linear rod drive installation for oil production, in accordance with the claimed utility model.

The following notation is used in the circuit:

1 - Support

2 - Base

3 - Wellhead

4 - Electric motor

5 - Reducer

6 - Cover-guide.

7 - Case

8 - Rail

9 - Damper

10 - Bearing support

11 - Gear

12 - Guides.

In FIG. 5, FIG. 6 and FIG. 7 shows a cross section of a rail with options for the shape of the channel (hole).

The device operates as follows.

The pump drive is installed directly at the wellhead on the wellhead flange and is fastened with support 1 with studs. The base 2 is designed to install the housing 7 at a predetermined height, and serves as an oil bath for lubricating the rack 8 and gear 11. In the case 7 are installed rails 12 for fixing the rack 8 and gear 11. On the body 7 there is a gear 5 with an electric motor 4 that drives the gear . The reversible electric motor 4 connected to the rack and pinion mechanism through the gearbox 5 and gear 11 moves the rail up and down to move the wellhead rod 3. During each stroke, the rack is lubricated by immersion in oil poured into the base 2.

Wellhead 3 passes through the channel inside the rack and is supported from above by a bearing support 10 above the center of the wellhead. The wellhead is not fixed along the axis, and is able to move inside the rack in the event of a stick or pump.

Damper 9 is designed to support the rail in the lower position when repairs are stopped, and to prevent it from going beyond the operating range in the event of equipment failure.

Examples of technical solutions.

The authors of the claimed technical model as a useful model have an example of a developed design of a linear drive of a sucker rod pump (LPSHGN).

The first solution includes LPSHGN of the claimed design with a bearing support, which eliminates the torque that occurs when working from the pump and rods in the well.

The second solution includes the LPSHGN of the claimed design with a rotator designed for forced rotation of the rods. Which is mounted on a bearing support. And uses oblique guides and a ratchet mechanism to convert reciprocating motion into rotational motion.

Claims (3)

1. Linear rack drive of a sucker rod pump for oil production, including an electric drive unit, a rack drive, consisting of a rack with a gear rack, a pinion drive gear, functionally connected to the output element of the drive unit, an attachment unit for a polished rod column, characterized in that the rack rack has a rounded cross-section, and there is a support bearing assembly for supporting the rod suspension. 2. The linear rack drive of the sucker rod pump for oil production according to claim 1, characterized in that it contains an electric or mechanical rod rotator mounted on a bearing support. 3. The linear rack-and-pinion drive of a sucker-rod sucker-rod pump for oil production according to claim 1, characterized in that the staff is made with an open channel through its length, designed to accommodate a polished rod, the axis of which is parallel to the axis of the working stroke of the sucker-rod pump.

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