RU2217269C1 - Apparatus for drilling pressurized equipment - Google Patents

Abstract

FIELD: gas and oil production industry branches, geological exploration. SUBSTANCE: apparatus includes housing, spindle with drill, feed screw, joined flange with unit for controlling pressure, pilot wheel for providing rotation and translatory motion of drill. In order to drill equipment under high pressure spindle with hexahedral cross section is mounted with possibility of reciprocation motion in housing whose inner cavity in lower portion has hexahedral cross section for transmitting rotation to spindle. Spindle has along its whole length cavity for feed screw and it has in its wall two drilled openings for passing working fluid pressure from inner cavity of drilled equipment into inner cavity of apparatus in order to equalize pressure values in inner cavity of housing and in cavity of drilled equipment. EFFECT: improved design providing release of pushing out effort from spindle. 1 dwg

Description

 The invention relates to the oil and gas and geological exploration industries and is intended for drilling the walls of technological equipment under pressure in order to communicate with the internal cavity for special work to eliminate emergencies or open gas and oil fountains.

 According to the Directory. Equipment and tools for the prevention and elimination of fountains. - M.: bowels. 1996, p.184 -186) there is a known design of a device designed for drilling the walls of oil assortment pipes under pressure in order to create communication channels with their internal cavity for carrying out technological operations. Drive controls - manual.

 The known device consists of three main parts: a clamp, a shutter and a tool.

The device allows the following types of work:
- drilling the walls of pipes of circular cross section, as well as a square profile (lead drill pipes);
- drilling gate valves;
- drilling the walls of the housings and elements of products under pressure;
- Constant pressure control in the cavity opened by drilling;
- Injection into the internal cavity of the drilled equipment of the process fluid.

However, the known design of the drilling device has the following significant disadvantages:
- the design is designed for use in work at pressures not exceeding 35 MPa, since the maximum working pressure for the sealing elements used in the device according to GOST 9833-73 does not allow the specified pressure to be exceeded;
- replacing the type of seal with a working one at higher working pressures, as well as an increase in the strength characteristics of the structure, does not allow the device to be used for working at high pressures, since the buoyant force arising after opening the walls of the equipment acting on the device’s spindle becomes insurmountable when the helm rotates manually tool feed.

 The main objective of the proposed technical solution is to ensure the drilling process of equipment under high (more than 35 MPa) pressure.

 The technical result achieved in this case is the compensation of the buoyant forces acting on the spindle arising after opening the cavity of the drilled equipment.

 The problem is solved as follows.

 In a device for drilling equipment under pressure and consisting of a housing, a spindle with a drill, a threaded spindle, a connecting flange with a pressure control unit, steering wheels for the translational and rotational movements of the drill, the spindle has a hexagonal section and is installed with the possibility of reciprocating motion in case, the inner cavity of which in the lower part has a hexagonal cross-section, which ensures the rotation of the spindle with rotational motion, while in the wall of the spindle, provided throughout without a cavity for passing the lead screw, two holes were drilled for transferring the pressure of the working medium from the internal cavity of the drilled equipment into the internal cavity of the device, ensuring equalization of the pressure of the working medium in the internal cavity of the housing and the cavity of the drilled equipment and removing the buoyancy force from the spindle.

 The design of the proposed device for drilling equipment under pressure (hereinafter referred to as the device) is shown in the drawing.

 The device consists of a hollow body 1, a hollow spindle 2 concentrically located in it with a drill 3 fixed on its lower end, a lead screw 4 with an external trapezoidal left thread, a connecting flange 5 with a pressure control unit in the cavity of the device 6 and a sealing assembly located inside it 7, a union nut 8 with four bolts 9 fixing it on the flange; in the upper part of the housing there is a sealing assembly 10, and a nut 11 is screwed onto its threaded part with four bolts 12 fixing it on the housing. The housing 1 is manually rotated by the helm 13 in the bearing assembly 14, and the lead screw 4 is rotated by the helm 15 in the bearing node 16. The internal cavity of the housing 1 along the entire length is made of cylindrical shape with the exception of its lower part, made of a hexagonal shape. The outer surface of the spindle 2 along the entire length is made hexagonal, included in the hexagonal hole in the housing 1 (section AA).

 The inner cavity of the spindle is cylindrical, its upper part is made in the form of a nut with a thread mating with the thread of the screw 4. In the walls of the spindle, holes 17 and 18 are drilled to transfer the pressure of the working fluid "P" from the cavity of the equipment into the cavity of the device. The device is attached to the equipment to be drilled by means of a valve 19, which is a T-unit that cuts off the pressure of the working medium during its assembly and disassembly.

 For the drilling operation, the equipment being drilled is equipped with a special sealed unit having a connecting flange of the same size as the flange of the shut-off valve.

 Compensation of the emerging buoyant force to the spindle 2 is carried out by transferring the pressure of the working fluid "P" (through the hole 17 - the annular gap between the walls of the spindle 2 and the screw 4 - the hole 18) into the internal cavity of the housing 1, which is sealed against the external environment due to the sealing units 7 and 10.

 The procedure for working with the device is as follows.

 Flange 5, the device is mounted on a closed gate valve 19, which is pre-installed on the drilled equipment, equipped with a special tight assembly.

 After it is opened, the helical screw 4 is rotated clockwise by the steering wheel 15, as a result of which the spindle 2 with the drill 3 translationally moves through the open valve 19 into the equipment cavity until it stops with the drill at the drilling site, after which the housing rotates clockwise with the helm 13 1 and, accordingly, a spindle with a drill.

 With the simultaneous rotation of the steering wheels 13 and 15 is drilling.

 After the end of the drill is opened, the internal cavity of the equipment being drilled, the pressure of the medium passes into the cavity of the device and, acting on the cross-sectional area of the spindle, creates a buoyancy force that prevents further input of the spindle. Through the holes "17" and "18" drilled in the spindle wall, the pressure of the working medium is transferred to the upper part of the internal cavity of the housing 1 and thereby compensates for the buoyant force. For further drilling, operating personnel need to overcome only the friction forces in the bearing and sealing units, without spending energy to overcome the buoyancy force.

 After the drilling process is completed, the spindle is rotated counter-clockwise by turning the steering wheel 15 from the equipment cavity, the shut-off (shut-off) valve is closed, by unit 6 the pressure from the internal cavity of the device is vented to the atmosphere and the device is dismantled.

 The device can be used in other industries: petrochemical, chemical, etc.

 Pipes, stop valves, pressure vessels, etc. can also be objects of drilling.

Claims (1)

Device for drilling equipment under pressure, consisting of a housing, a spindle with a drill, a threaded spindle, a connecting flange with a pressure control unit, steering wheels for translational and rotational movement of the drill, characterized in that the spindle having a hexagonal cross-section is installed with the possibility of return - translational motion in the housing, the inner cavity of which at the bottom has a hexagonal cross-section, which provides the spindle with rotational motion, while in the spindle wall, you olnennogo the entire length of the cavity for the passage of the screw shaft, two holes are drilled for bypassing working fluid from the internal cavity drilled into the inner cavity equipment device for providing equalization of pressure values in the internal cavity of the housing and a cavity drilled equipment and removal of the ejecting force from the spindle.