RU2327859C1 - Double-ended hydromechanical slot perforator - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the drilling and production activity of the oil, gas and injection wells. The device contains a body where the puller piston and the telescopic cutting instrument made as upper and lower cutting disks which enable cutting two diametrical slots in column, are installed. Each disk is installed on its axis. The telescopic mechanism is made as the balance arm assembled on the central axis. The balance arm is made so as to enable rotating at relocation of puller piston. In the balance arm, at the different distance from the central axis, the axes of the cutting disks are installed. The length of the balance arm to the upper disk axis is less than that to the lower disk axis. The device enables the firm development of the flow string simultaneously with two disks, and increased durability of the cutting disks.

EFFECT: development of the flow string simultaneously with two disks, and increased durability of the cutting disks are provided.

4 dwg

Description

The invention relates to the field of drilling and operation of oil, gas and injection wells, and in particular to a device for the secondary opening of formations by creating longitudinal perforations in the casing (production) columns and the formation of filtration channels in the bottomhole formation zone.

The prior art devices for slotted perforation of casing strings based on the use of a retractable rolling cutting tool. Such a device is disclosed, for example, in RU 2151858 C1, 06/27/2000, RU 2180038 C1, 02/27/2002, in US 4119151 A1, 10/10/1978. The described devices differ mainly in the design of the mechanism of attachment and extension of the cutting tool.

The main disadvantage of these devices is the rapid wear of working parts, including the elements on which the rolling roller is mounted, as well as the difficulty of replacing the cutting tool, which requires complete disassembly of the device.

Known hydromechanical downhole drill according to patent RU 2182221 C1, IPC 7 ЕВВ 43/114, 05/10/2002. The drill includes a housing, a cutting tool in the form of a rolling disk, a hydraulic nozzle, a hollow rod filter located in two hydraulic cylinders, a piston-pusher with hydraulic channels associated with the axis of the rolling disk located in the guide grooves of the side plates, which cover the wedge groove containing removable plates. Its components are easy to manufacture and easy to replace.

However, when the cutting tool acts on the production casing unilaterally, a pressure is applied to the device against it, requiring additional efforts to overcome the frictional force when moving the device up and down and leading to its rapid wear. In addition, the design of the device is quite complex, which reduces its reliability and manufacturability during operation.

The closest analogue (prototype) of the proposed device can be considered a hydromechanical slotted drill, disclosed in RU 2249678 C1, 04/10/2005, containing a retractable cutting tool in the form of two cutting disks mounted on the axis with a mechanism for their extension, with the possibility of making two diametrically located slots in the disks the column, while the mechanism of the extension of the cutting discs is made in the form of a beam mounted on the central axis, in the shoulders of which the axes of the discs are mounted in the holes with the possibility of rotation when changing enii piston-pusher.

The work of the hammer is based on the principle of plastic deformation of the metal from the load at each point. As an opening element, in the devices used, rolling disks are used, mounted on the beam and having two positions - working and transport.

However, when the disks reach the working position, one disk is located above the other, which causes the perforator to skew relative to the axis of the well and change the load arm on the beam. Opening of the column occurs unevenly, which increases the load on the upper rolling disk and the axis and can lead to premature wear. In addition, due to the fact that the upper rolling disk quickly opens the column wall and extends beyond it, the radial force on the lower disk is significantly reduced, which leads to under-opening of the production casing and lowering the quality of the work performed.

The objective of the invention is to increase the reliability and manufacturability of the punch, providing increased efficiency and productivity of the process.

The technical result that provides a solution to this problem lies in the possibility of guaranteed opening of the production casing simultaneously with two disks. The improved design of the rocker distributes the generated force evenly on each disc and axis, which increases their wear resistance and runtime without changing the cutting unit.

This technical result is achieved due to the fact that in the perforator hydromechanical slotted, containing a housing, a plunger-piston placed therein and a retractable cutting tool in the form of upper and lower cutting disks for making two diametrically located slots in the column, each of which is mounted on its axis , as well as the mechanism of their extension in the form of a beam mounted on a central axis, in the shoulders of which the axes of the cutting discs are installed, and made with the possibility of rotation when moving the piston-pusher , according to the invention, the disks are mounted at different distances of their axes from the central axis of the rocker arm, while the length of the arm of the rocker arm to the axis of the upper disc is less than the length of the arm of the rocker arm to the axis of the lower disc.

Figure 1 shows the location of the upper 1 and lower 2 knob disks at the exit to the working position in accordance with the prototype. With equal arms of the rocker arm, there is a slight skew of the punch relative to the axis of the well and a change in the shoulder load on the rocker arm. In this position, a unilateral gap t is formed between the punch and the inner diameter of the column, which is determined by the formula: t = Din.k-Dp., Where Dvn.k is the inner diameter of the column, Dp is the outer diameter of the perforator.

For example, with the outer diameter of the casing string Dн.к = 146 mm, the diameter of the perforator Dп = 115 mm, the wall thickness of the column δ = 10 mm and the working stroke of the disk is 28 mm, the output of the disks h behind the column wall will be:

For the upper disk: h = (28-δ) = 28-10 = 18 mm.

For the lower disk: h ₁ = (28-δ-t) = 28-10-11 = 7 mm,

where t = D int.-Dp. = (146-2 × δ) -115 = 126-115 = 11 mm.

Different lengths of the arms of the rocker arm (different turning radius of the upper and lower disks) can reduce the reduced difference in the exit of the disks beyond the casing wall.

Figure 2 shows the location of the upper 1 and lower 2 knurled disks when entering the working position in accordance with the proposed design of the perforator. Under these operating conditions, the working stroke of the upper disk is 28 mm, and the lower disk is 33.3 mm. The output of the disks outside the column is h = 18 mm for the upper disk, and h ₁ = 13 mm for the lower _one .

The above calculations show that in the case of using a perforator with different lengths of the arms of the rocker arm, its skew relative to the axis of the well is significantly reduced.

Figure 3 and figure 4 schematically shows the complete assembly in the initial position and operating position (dotted line): respectively, the prototype and the proposed design.

The perforator includes a housing 3, in which a sleeve (not shown) for connecting tubing (tubing), hydraulic cylinders with a piston-pusher having hydraulic channels with hydraulic nozzles (not shown) are placed. The housing of the cutting unit is connected to the lower hydraulic cylinder, on the central axis 4 of which is located the beam 5, made, for example, in the form of two curly plates, between which the upper 1 and lower 2 cutting discs are located on the axles 6.

The device operates as follows.

On the tubing string, the perforator is lowered into the well to the cutting site. Having installed the device in the well, a direct washing of the pipe cavity and the device cavity is carried out from scale and mechanical impurities that enter the pipe cavity during geophysical work on binding the device to the cutting interval. Then, a ball with a diameter of 19 mm is lowered into the pipe cavity, which, passing through the elements of the perforator, blocks the central channel of the piston-pusher, after which working pressure is created in the tubing.

When creating a working pressure in the pipe cavity, the fluid acts on the plunger piston. Moving progressively along the axis of the device, he turns the rocker 5, between the plates of which on the axes 6 there are cutting discs 1 and 2, and pushes them all the way with the production casing 7.

Creating step pressure in the tubing cavity from 10 to 80 atmospheres, increase the force of indentation of the cutting discs 1 and 2 in opposite directions of the production string 7.

The slit is rolled by two cutting discs by alternately moving the device under pressure up and down the length of the slit. After the formation of cracks in the production casing 7, the pressure in the pipe cavity is raised, and the jet monitor effect is realized. Two jets of liquid exiting through the hydraulic nozzles, with high speed, destroy the cement stone and the rock behind the production string, wash the cavity along the entire length of the cracks. After washing the cavity, the pressure in the pipes is reset to atmospheric. The plunger piston is retracted into the lower hydraulic cylinder and restores the entire cutting unit assembly to its original position. After that, a large-diameter ball — 40 mm — drops into the tubing cavity, which sits in the socket of the shear circulation valve. Raising the pressure in the pipes, open the flushing device in the housing. After that, development, or killing of the production well, or lifting of the device from it are carried out.

The technical and economic advantages of the proposed perforator are as follows.

1. The use of a rocker with different lengths of shoulders allows you to guaranteedly open the production casing simultaneously with two rollers;

2. This design of the rocker distributes the generated force evenly on each roller and axis, which increases their wear resistance and the operating time of the punch without replacing the cutting unit.

Claims (1)

A slotted hydromechanical puncher, comprising a housing, a pusher-piston placed therein, and a retractable cutting tool in the form of an upper and lower cutting discs for making two diametrically arranged slots in the column, each of which is mounted on its own axis, as well as a mechanism for their extension in the form of mounted on the Central axis of the rocker arm, in the shoulders of which the axes of the cutting discs are installed, and made with the possibility of rotation when moving the piston-pusher, characterized in that the discs are installed at different distances its axes from the central axis of the rocker arm, while the length of the arm of the rocker arm to the axis of the upper disc is less than the length of the arm of the rocker arm to the axis of the lower disc.

Images