GB2253022A

GB2253022A - Josher control valve

Info

Publication number: GB2253022A
Application number: GB9103948A
Authority: GB
Inventors: John Enver Emim; Michael Arthur Oliver
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-01-12
Filing date: 1991-02-26
Publication date: 1992-08-26
Anticipated expiration: 2011-02-26
Also published as: GB2253022B; GB9103948D0

Abstract

Control valve apparatus for controlling flow in a pipeline, which valve apparatus comprises a valve and cutter means, and which valve apparatus is such that it is able to be cut into the pipeline without having to stop the flow in the pipeline. The cutter means may have a cutting head which is rotateable to cut a section of the pipeline and which is able to accommodate the cut section of the pipeline. A plug or valve may then be introduced into the pipeline to block the flow (see Figs, not shown). <IMAGE>

Description

JOSHER CONTROL VALVE The object of the device is to enable the flow within a live pipeline to be controlled by provision of a stop valve without interruption of the flow whilst the valve is being fitted.

The device consists of four basic parts and its operation is as follows: Part 1.

The first part of the device consists of a tee piece which is in two parts, to enable it to be fitted over an existing live pipe. The two parts of the device are bolted together via an edge flange and sealed to each other by a gasket along the whole length of the joint, the number and type of bolts depending on application. The device is provided with serrated edges on its internal diameter in order to give both a high friction grip and to seal the device to the existing pipe. The tee piece is provided with reinforcing plates to strengthen the joint and their size and frequency will be adapted to suit the working pressures of the existing live pipe. The fitting is also provided with a test valve for monitoring pressure and for insertion of lubricating fluids during the cutting stage.

The location groove is only required to position the stop valve which is inserted during stage 4 and has sprung location clips for this purpose.

Part 2.

The second part consists of a valve which is bolted to the tee piece by a conventional flange plate and gasket system, the type and strength of the valve will vary according to the pressure requirements, the sole purpose of this valve is to provide isolation of the tee connection after the existing pipe wall has been cut through.

Part 3.

The cutter assembly is bolted to the valve by flange connection and the cutting head passes through the opened valve body and locates against the existing pipe wall within the tee piece, the valve is opened and the tee piece is partially filled with lubricant to assist the cutting head. The cutting head is rotated until a section of the existing live pipe is removed. The cutting head accommodates the cut section of pipe and both are withdrawn through the valve body.

The valve is then closed and the cutting assembly is unbolted and removed.

Part 4.

The stop valve body is now bolted into the same position as the cutting head assembly after opening the isolating valve and is rotated through the valve body until it reaches the tee piece. The stop valve is located in the correct place by means of sprung loaded clips and a location groove prior to its entry into the live pipe.

The bullet valve enters the pipe line and continues until it has fully closed the pipes apertures. The bullet valve is designed to suit the job it is to do for example the valve surfaces may be lined with soft metal that would enable the valve to seat better or a softer rubberised surface that would allow the seating of the movable valve being inserted much more tolerance to be compressed on to the internal surface for a better fit of the internal surface of the inertia of the live pipeline that is being controlled.

The device can be made to suit any size of pipe and enables the flow to be controlled by either insertion or removal of the bullet valve. The body of the valve would be manufactured with materials strong enough to cope with the pressures the valve is expected to withstand.

As a form of example bronze cast steel or stainless steel to withstand high pressures, aluminium or light alloy for lower pressures.

PROCESS TO FIT THE JOSHED CONTROL VALVE.

Though there is a general process to fit the valve which is described above there is also a special preparatory process that we believe is unique that we wish to protect. The process and valve are dependent on each other because the process requires the valve to be available and the valve requires the process to be carried out before fitting of the valve.

In the event of damage to a oil well head and associated control valves and the oil/gas is on fire causing extremes of temperature that cannot be easily approached.

In some cases, these oil well fires can take a considerable amount of time to control, some could be considered out of control and present day methods sometimes means the loss of the deep oil pipe, however our method is unique in that the heat of the fire can not affect the work force due to the method and the deep oil well pipe once controlled can be reused without loss of the oil well.

The main problem of an oil well fire is the harsh conditions that prevail in and around the area of the damaged pipe, the heat smoke and general condition is hostile to any work force so to overcome this problem we have devised the following process to protect the working team from hazards.

1) The process requires that a decision be taken as to where best to start the#process,#see position A this position is variable and is dependent on, both wind direction, intensity of the heat and ground conditions. However a general rule of thumb is position A is situated as close to the damaged oil well fire as possible that will enable a trench to be safely excavated probably by mechanical means to a depth of approximately thirty feet however the depth can be varied to suit individual site conditions, there is no reason why it can not be deeper or shallower the main criteria is the insulation protection that would be afforded by the earth cover. Initially the trench could be extended away from the heat source and then with the bottom of the trench being sloped up to the ground surface.

Parts of the trench can if required be covered over with some form of shuttering and soil to further insulate some or all of what will be termed the approach. The side walls should be shuttered and secured from falling into the trench.

The sloping trench bottom is considered helpful so that the work force can gain entry to the work area immediately below point A without being subjected to the heat at point A and that slope would allow machinery and plant to be easily accessed to the start of the next part of the process. The slope is not fundamentally important as in some cases due to lack of space an access shaft at point A might be all that can be sensibly achieved.

The choise of approach to the tunnel head is not important, however the depth must be sufficient to provide the appropriate protection. The final approach from point A is achieved by normal tunneling methods, and may be by machine or hand to suit site conditions.

2) Consideration of how to remove the resulting spoil in the next part of the process must be considered which can be by manual or mechanical means.

3) From the bottom of the trench below point A the soil is removed so the work team can move forward, towards the rising oil well at the depth chosen that would afford all the protection required from the harsh environment above.

As the work team move forward they carry out all necessary shoring to prevent the horizontal tunnel from collapse. The size of tunnel will be dependent on room required to move equipment and materials as well as removing spoil.

4) On reaching the oil well external vertical casing the work team would prepare enough space to carry out the next phase of the work. At this stage the vertical casing would be exposed around its outer diameter rising from the floor and exiting through the ceiling of the undergound excavation.

It may be necessary before cutting away the outer linings for some form of grout to be injected, where cavitation within the original interlining-- fill may have occurred, in order to ensure the integrity of the casings.

5) After cutting away and securing as necessary the outer linings of the production string, the valve can be fitted as indicated above.

6) -In the event that oil production is required while the above ground repairs take place the Josher control valve system can offer the facility of redirecting the full bore flow by merely fitting another valve below the valve that has been closed down.

7) The Josher Valve can be either manually operated, that is to say the cutting head can be turned by hand to remove part of the live pipe, or some form of turning force can be applied, for example hydraulic or electrical powered tools.

8) The valves can be remotely controlled to either cut as above or close or open again using the appropriate external power.

9) The valve could be used in a marine environment and installed under water.

10) The Josher control valve has several functions, that ought to be clearly stated.

11) By its design it allows the user to cut into a pipe system that is under pressure, either with gas or liquid.

12) Part of the fitting process is to stabilise the annular space between the last casing and the production string (strings). The problem is that there might be gas or oil under pressure that could ignite when the casing is cut causing serious problems.

13) Before fitting the Josher Control Valve the last casing surrounding the production string (strings) must be removed but before doing so the annular space is tested.

14) To carry out this important task the appropriate size Josher valve assembly, consisting the T piece and cutting and isolation valve together with the by-pass assembly is fitted. The desired cutter is used to penetrate the casing.

15) The pressure can now be bled off and checked, the by-pass can be connected to a mud pump and the annulus filled as required to stabilise any pressure. Cement may be used under certain circumstances.

16) Once having carried out the above process and stabilised the annulus the valve assembly is removed and put aside.

17) The last casing is then: removed by cutting, revealing the production string (strings).

18) The correct size Josher Valve assembly is then prepared to be fitted.

19) Once bolted in position and the cutting process initiated and completed, the bullet valve is assembled in position. In certain circumstances the JVC can be fitted with a by-pass facility, where the bullet valve is hollowed out with the desired diameter passage to allow for the flow to the by-pass through the body of the JVC via an external flange and control. The by-pass can be of any diameter to suit the conditions that the valve will have to contend with.

20) The by-pass valve gives direct access to the production string and can be used to pump mud into the string in order to control or kill the well.

21) To cater for high pressure circumstances the bullet valve can be manufactured from hard steel and the surfaces on it forming the seal that will come into contact with the inside of the production string be slightly raised so to embed into the milder steel production string when the bullet is fully wound in.

Claims

1. Control valve apparatus for controlling flow in a pipeline, which valve apparatus comprises a valve and cutter means, and which valve apparatus is such that it is able to be cut into the pipeline without having to stop the flow in the pipeline.

2. Control valve apparatus according to claim 1 in which the cutter means has a cutting head which is constructed to be rotatable to cut a section of the pipeline and which is constructed such as to accommodate the cut section of the pipeline.

3. Control apparatus according to claim 2 in which the valve has a valve body through which the cutting head is withdrawn after the section of the pipeline has been cut.

4. Control valve apparatus according to claim 3 in which the cutter means is secured to the valve such that after the cutting head has been withdrawn from the valve body, the valve is closeable and the cutter means is releaseable from the valve.

5. Control valve apparatus according to claim 4 in which the cutter means is secured to the valve by bolts.

6. Control valve apparatus according to any one of claims 2 to 5 in which the cutting head is rotateable manually or by a powered tool.

7. Control valve apparatus according to any one of the preceding claims in which the valve is a remotely controlable valve.

8. Control valve apparatus according to any one of the preceding claims and including a two part device for fitting over the pipeline and for being sealed in position on the pipeline.

9. Control valve apparatus according to claim 8 in which the two part device is a tee piece.

10. Control valve apparatus according to claim 8 or claim 9 in which the two part device has an internal diameter portion having serrated edges for giving a friction grip and for sealing the two part device to the pipeline.

11. Control valve apparatus according to any one of claims 8 to 10 in which the two part device includes a pressure monitor and lubricating device for monitoring pressure in the pipeline and for enabling the insertion of lubricating fluid during the cutting of the section of the pipeline.

12. Control valve apparatus according to any one of the preceding claims in which the valve is locateable in a desired position on the pipeline by means of spring loaded clips and a location groove.

13. Control valve apparatus for controlling flow in a pipeline, substantially as herein described with reference to the accompanying drawings.

14. A process for controlling flow in a pipeline that is on fire, which process comprising determining the best position to approach the pipeline, digging a trench so that the pipeline is approached below ground level, and fitting the control valve as claimed in any one of claims 1 to 13.

150 A process according to claim 14 in which the pipeline is encountered in a tunnel which extends from the trench to the pipeline.

16. A process for controlling flow in a pipeline that is on fire, substantially as herein described with reference to the accompanying drawings.