RU2351379C1 - Facility for preventing fire on mains transporting oil and gas - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: facility consists of main with ram preventer cut into section of main; and before preventer in the main there is assembled one or two connectors with valve installed on connector(s). Operating pressure is supplied from the main under the piston of the valve which compresses a calibrated spring of the piston rod and connects under-piston cavities of hydro-cylinders with a hydro-accumulator (pneumatic vessel of high pressure). Pressure of the hydro-accumulator opens rams of the preventer; and above-piston cavities of the hydro-cylinders communicate with open air. At destruction of the main (pressure after preventer drops both in the main and under the piston of the valve) the spring returns the rod of the valve into initial position, and cavities of hydro-cylinders communicate with hydro-accumulator and open air in a reverse order; rams of the preventer close its pass-through section. Access of product into the destructed bleeding main is shut off. The facility is installed before essential objects along main routs of oil and gas transporting such as railways and automobile roads, industrial and populated places, rivers, bridges etc, and also at heads of wells.

EFFECT: invention facilitates simplification of design and increases reliability of facility.

2 cl, 1 dwg

Description

The invention relates to the gas and oil industry and can be used to prevent product loss, fire and environmental pollution during the destruction of the ground pipeline for oil and gas transport and wellhead.

The prototype of the invention is a device for sealing the wellhead, containing a preventer installed in the cross section of the main pipeline, including a die shut-off element and drive hydraulic cylinders with a mechanism for automatically operating the preventer, made in the form of a spool with a spring-loaded rod and grooves of the pipeline that communicate with the cavity of the main pipeline, hydraulic cylinders and the atmosphere [1].

The disadvantage of the prototype is the design complexity and low reliability. This is due to the presence of a piston cylinder and a spool, both the first and the grooves of the spool rod, have direct contact with the product, in particular oil. In winter conditions, in the cavities of the cylinder and spool, the oil cools and its viscosity increases, which can lead to failure of the spool. In summer conditions, oil tends to settle in the form of a solid (highly viscous) film on hot (heated by the sun) surfaces, which will inevitably lead to failure of the spool due to obstruction of its pistons in the housing.

The invention allows to obtain a new technical effect - simplifying the design and increasing reliability.

This technical effect is achieved by the fact that the valve body is mounted on the fitting of the pressure main pipeline to the preventer communicating with the piston cavity of the valve stem, and the grooves of the rod alternately communicate with the piston cavities of the hydraulic cylinders and the hydraulic accumulator, and vice versa, with the piston cavities and the hydraulic accumulator and piston pistons , the spool housing is mounted on two fittings of the main pipeline, and a transverse visor is fixed between the fittings in the pipeline.

This embodiment ensures the operation of the spool on a clean slurry, for example, alcohol-glycerin and other mixtures, which eliminates any thickening all year round, and also provides heating of the under-piston part of the spool with a heated product when pumping it.

The drawing shows a General view of a device for preventing fire on the main pipelines for transporting oil and gas in cross section.

A device for preventing fire on oil and gas transmission pipelines includes a pressure main pipe 1, on which a feed coil 2 is installed through the flanges. A die preventer 3 is installed on the coil 2 in the same way, followed by a discharge main pipe 4. The preventer 3 has grooves 5, in which the dies 6 with hydraulic cylinders are located 7. The passage coil 2 is mainly provided with two fittings 8 with valve (s) 9, on which the valve body 10 is installed, in which the stem 11 installed four pistons 12-15. In the case 10 of the spool between each pair of the mentioned pistons, the nozzles 16-20 are evenly cut, and the rod 11 is spring-loaded with a calibrated spring 21. A visor 22 is installed between the nozzles 8 in the passage coil 2. The device is equipped with a hydraulic accumulator (or high pressure pneumatic vessel) 23 with a valve 24, which by pipelines 25 and 26, respectively, communicates with fittings 16 and 20 of the valve body 10. The fitting 17 is connected by a pipe 28 to the piston cavities, and the fitting 19 by the pipe 27 - to the piston cavities of the hydraulic cylinders 7.

A device for preventing fire on the main pipelines of oil and gas transport works as follows.

When the working pressure in the pressure main pipe 1, passage coil 2, preventer 3 and outlet main pipe 4 through the nozzle (nozzle) 8 and the open valve 9, the working pressure enters the housing 10 under the piston 12 of the spool, moves it to the right (according to the drawing) and through the rod 11 compresses the calibrated spring 21. At this time, the fittings 16 and 17 are in the groove between the pistons 12 and 13. The pressure from the accumulator 23 through the open valve 24, pipe 25, the groove between the pistons 12 and 13 of the valve body 10, the fitting 17 and the pipe 28 served I into the sub-piston cavities of the hydraulic cylinders 7. At the same time, the supra-piston cavities of the hydraulic cylinders 7 through the pipe 27, the fitting 19, the cavity in the groove between the pistons 13 and 14 and the fitting 18 of the valve body 10 communicate with the atmosphere. Over this line, overpressure is discharged from the over-piston cavities of the hydraulic cylinders 7. The pistons of the hydraulic cylinders 7 with their rods pull the dies 6 along the grooves 5 and open the bore of the preventer 3. This ensures that the product passes through the pressure main pipe 1, coil 2 and preventer 3 into the discharge main pipe 4, ensuring the transportation of the product (oil or gas).

When the discharge main pipe 4 is destroyed in the entire system, a pressure drop below the working pressure occurs, which is transmitted through the fittings (nozzle) 8 under the piston 12 of the valve body 10, the spring 21 is opened and moves the rod 11 with the pistons 12-15 to the left (according to the drawing). The fittings 17 and 18 are located in the groove between the pistons 13 and 14, and the fittings 19 and 20 are located in the groove between the pistons 14 and 15 of the valve body 10. The pressure from the hydraulic accumulator 23 through the valve 24, the pipe 26, the groove between the pistons 14 and 15, the fitting 19 through the pipe 27 is supplied to the over-piston cavities of the hydraulic cylinders 7, the pistons move in them and their rods opposite the grooves 5 move the plates 6, which converge and overlap the passage the cross section of the preventer 3, thereby preventing the product from passing into the destroyed main pipeline 4. At the same time, the piston cavities of the hydraulic cylinders 7 through the pipe 28, the fitting 17, the groove between the pistons 13 and 14 and the fitting 18 of the valve body 10 together come with the atmosphere. Along this line, excess pressure is released from the over-piston cavities of the hydraulic cylinders 7.

After repair and restoration of the main pipeline 4 resume pumping of the product. The pressure in the discharge main pipe 1, the passage coil 2 and the preventer 3 to the dies 6 increases to the working one, which through the nozzle (nozzle) 8 enters the piston 12 of the valve body 10, and the operation cycle is repeated as described above.

When the device is operating and product is pumped through main pipelines 1 and 4, a certain pressure drop occurs in the cavity of the passage coil 2 on the visor 22, which tends to equalize by flowing the product through the nozzle 8 to the visor 22, valve 9, the cavity under the piston 12 of the valve body 10 and the nozzle 8 after the visor 22, thereby ensuring heating of this working part of the valve body 10 and flushing of the cavity of the housing 10 under the piston 12. This eliminates thickening and deposits on the walls of the cavity, which increases the reliability of operation.

The volume and pressure of the accumulator 23 is calculated for at least two operations - opening and closing. It is permissible to calculate the accumulator for several cycles. After generating cycles, the accumulator 23 is replaced, which does not happen so often. The device can be equipped with two hydraulic accumulators - on the pipe 25 and pipe 26.

Instead of the accumulator 23, it is permissible to use a high-pressure pneumatic tank with a gearbox.

Thus, emergency automatic shutoff of the main pipeline for oil and gas transport is ensured, which prevents the obvious possibility of fire, loss of product and environmental pollution.

Claims (2)

1. A device for preventing fire on the main pipelines of oil and gas transport, containing a preventer installed in the cross section of the main pipeline, including a die shut-off element and drive hydraulic cylinders with a mechanism for automatically operating the preventer, made in the form of a spool with a spring-loaded rod and grooves on it, which communicate with cavity of the main pipeline, hydraulic cylinders and atmosphere, characterized in that the valve body is mounted on the pressure head pipelines to the preventer communicating with the piston piston rod cavity, and the grooves of the rod between the piston pistons alternately communicate with the piston or piston cavities of the hydraulic cylinders and the accumulator, or piston or piston cavities with the atmosphere. 2. The device according to claim 1, characterized in that the valve body is mounted on two fittings of the pressure main pipeline, and a transverse visor is fixed between the fittings in the pipeline.