GB2264313A

GB2264313A - Self closing safety valve for oil/gas drilling pipe-lines.

Info

Publication number: GB2264313A
Application number: GB9123324A
Authority: GB
Inventors: John Victor Kernaghan; Micheal John Lengthorn
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-11-04
Filing date: 1991-11-04
Publication date: 1993-08-25
Also published as: GB9123324D0

Abstract

The valve is an integral part of a pipe section A which forms the pipe-line from the below-surface gas/oil source, to the drilling rig/well-head. The pipe wall is hollow to allow the flow of hydraulic fluid which maintains the position of a retaining sleeve C which in turn holds open the valve fins E and allows free flow of material through the pipe-line. Hydraulic pressure is maintained within the wall of the pipe by a jockey pump and a connecting hose and a non- return valve, all of which are positioned at the well-head. In the event of fire/explosion at the well head, the system fails safe, and the valve E is forced closed resulting in no flow within the pipe Line. The system can be designed to allow several valves to be installed 'in line'. <IMAGE>

Description

SELF CLOSING SAFETY VALVE FOR OIL/GAS DRILLING PIPE LINES.

This invention relates to a device which will automatically close the pipe-line from a surface mounted drilling platform or well-head to a bellow ground oil or gas source.

The war in the Middle East has demonstrated the terrible consequences - both environmentally and financially - in the event of large scale oil well fires.

At present, the emphasis, in terms of technological development is aimed at increasing the efficiency of extinguishing such fires which is usually an expensive and protracted exercise.

This invention is intended to restrict the flow of oil or gas within the pipe, thus stopping or severely limiting the release of flammable material to the atmosphere.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which; Figure 1 shows in perspective, the valve in position within the specially designed pipe-line, in an open position so as to allow material flow.

Figure 2 shows the same valve in a closed position so as to restrict flow; and Figure 3 shows a schematic of the valve, pipe-line and hydraulic pump mounted at the surface.

Referring to the drawings, the system comprises a hollow walled pipe section A, which allows hydraulic fluid to be pumped through the pipe-wall by a surface mounted jockey pump F, which forces the retaining sleeve C, to maintain its position and therefore hold back the valve fins E which would otherwise close due to the pressure generated by the normal flow of material within the pipe-line.

In the event of a fire or explosion at the well-head, the hydraulic connection G which supplies the hollow-walled pipe and therefore the valve, fails with the release of hydraulic pressure within the pipe wall.

The flow pressure within the pipe then forces the valve fins E to close, thus sealing the pipe-line and stopping the flow of material to the atmosphere.

The valve fins are secured to the outer wall of the pipe at hinge point D and the system may be recharged after use so that the retaining sleeve C is forced back over the valve fins E and normal flow is resumed.

Hydraulic pressure within the system is assisted by the use of a non-return valve H.

Claims

1. The self closing safety valve fore oil/gas drilling pipe-lines, comprises, a hollow walled, interconnectable pipe section which allows hydraulic fluid to hold a retaining sleeve in position which in turn, holds open a self closing valve, the fins of which protrude into the normal flow of material and are hinged upon the outer wall of the pipe so that in the case of hydraulic pressure loss (resulting from a fire or explosion at the well-head) the retaining sleeve is retracted and the valve is forced closed by the pressure of the material flowing within the pipe-line.

2. A self closing safety valve as claimed in claim 1 wherein connection means is provided to inter-connect multiple pipe sections.

3. A self closing safety valve as claimed in claim 1 or 2 wherein the valve may be incorporated as an independent unit which might connect standard pipe sections so as to provide the same function.

4 A self closing safety valve as claimed in claims 1,2 or 3 wherein hydraulic pressure within the system is maintained by a jockey pump positioned at the well-head which may have a remote method of pressure release in case of emergency.