GB2285819A

GB2285819A - A sub-sea manifold arrangement

Info

Publication number: GB2285819A
Application number: GB9401369A
Authority: GB
Inventors: David John William High
Original assignee: BRISCO ENG Ltd
Current assignee: BRISCO ENG Ltd
Priority date: 1994-01-25
Filing date: 1994-01-25
Publication date: 1995-07-26
Anticipated expiration: 2014-01-25
Also published as: GB2285819B; NO950254D0; NO308181B1; GB9401369D0; NO950254L

Abstract

A manifold arrangement 20 for distributing hydraulic fluid in a sub-sea environment comprises a manifold body (32, Fig. 4) having fluid passages therethrough and a plurality of valves mounted on the body to control flow through the fluid passages. The body having exit ports on at least three different faces thereof. The manifold is to be used in a sub-sea control module 10 comprising a casing 12 having a hydraulic fluid entry point, a power supply entry point and a plurality of hydraulic fluid exit points 28. The casing contains the manifold arrangement 20 which distributes hydraulic fluid from the entry point to the exit points 28. The control module 10 includes an electronic control unit 22 which receives signals from an external source 26 and controls the valves mounted on the manifold body in accordance with those signals. The control module 10 may also comprise a pressure compensating vessel 31 within the casing 12. <IMAGE>

Description

A MANIFOLD ARRANGEMENT This invention relates to a manifold arrangement, particularly to a manifold arrangement for distributing hydraulic fluid in a sub-sea environment.

In order to control the valves of a sub-sea wellhead, it is known to place on the sea bed close to the wellhead a control module containing remotely actuable valves which are connected to the wellhead valves and which can open and close the wellhead valves. The wellhead valves are conventionally mounted on a stub pipe standing up from the sea bed and conventionally referred to as a Christmas tree.

It is desirable to minimise the size and weight of such control module.

According to the present invention, there is provided a manifold arrangement for distributing hydraulic fluid in a sub-sea environment, the arrangement comprising a manifold body having fluid passages therethrough and a plurality of valves mounted on the body to control flow through the fluid passages, wherein the body has fluid exit ports on at least three different faces thereof.

The manifold body is preferably a generally rectangular, single piece of metal provided with gun-drilled intersecting bores to distribute hydraulic fluid as desired.

The block is preferably adapted to be mounted on one end face, with the exit ports being provided on faces which are perpendicular to the mounting face.

A hydraulic fluid filter device may be mounted on a face opposite to the mounting face.

The manifold arrangement is preferably mounted within a sealed casing, the casing being intended for positioning on the sea bed and being capable of withstanding the pressures imposed on the sea bed.

According to a second aspect of the invention, there is provided a sub-sea control module comprising a casing having a hydraulic fluid entry point, a power supply entry point and a plurality of hydraulic fluid exit points, the casing containing a manifold arrangement as set forth above for distributing hydraulic fluid from the entry point to the exit points, and an electronic control module adapted to receive signals from an external signal source and to control valves mounted on the manifold in accordance with those signals.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a cross section through a sub-sea control module in accordance with the invention; Figure 2 is a plan view of the module of Figure 1, with the lid removed; Figure 3 is provided for the sake of clarity and illustrates a rectangular block corresponding to a manifold body forming part of the invention, with the six faces of that body designated by the letters A, B, C, D, E and F, the faces A and D being opposite, the faces B and E being opposite and the faces C and F being opposite; Figure 4 is a view of a manifold arrangement in accordance with the invention on the face A, showing the manifold body populated with twelve valves; Figure 5 is a corresponding view on face D of the manifold body;; Figure 6 is a view of the manifold body on face B; Figures 7, 8, 9, 10, 11 and 12 are, respectively, views on the faces A, B, C, D, E and F showing the manifold body before other components are mounted to it.

Figure 1 shows a sub-sea control module generally designated 10 which comprises a sealed, pressurecompensated housing 12 with a plinth 14 and a lid 16. The module has lifting hooks 18 so that it can be lowered to the sea bed. The housing must be sealed and pressurecompensated to prevent any ingress of water when the module is in place on the sea bed, and this can be assisted by filling the empty space within the module, once the internal components have been assembled, with a dielectric liquid.

The module basically exists to selectively feed hydraulic fluid to one or more of a selection of wellhead valves, alongside which the module is to be located. The module will be located to the valves through short lengths of hydraulic tubing which will be connected to outlet ports on the module and to corresponding connection points on the wellhead valves.

Within the module 10 there are two manifolds, designated 20a and 20b. One manifold controls the supply of a high pressure fluid circuit and the other controls a low pressure circuit. There is a single feed of hydraulic fluid into each manifold, and the exits from the manifold are controlled by a number of different manifold valves.

The opening and closing of the manifold valves is itself controlled by an electronic control unit 22 mounted within the module.

The module has two external hydraulic fluid inlet ports, one communicating with each manifold, and an external electrical power inlet connection 26. In an alternative form of the module, there may be only a single hydraulic circuit.

The electrical power for operation of the module is supplied through a line connected to the connection 26, and the control signals for the module are superimposed on the current carried by the wire.

The module is thus in communication with the surface via two lines, one carrying electric current and the other carrying hydraulic fluid. There may be more than one hydraulic line. Signals can be sent from the surface to instruct the module to open and close the wellhead valves in any desired sequence.

The module can be set up to control different numbers of wellhead valves. Typically there may be from two to twenty-four (or more) hydraulic fluid outlet ports 28, and there will be a corresponding number of manifold valves contained within the module, so that each of the outlet ports is under the control of one of the manifold valves.

The module preferably also includes a hydraulic fluid filter unit 30 mounted on top of the manifold 20, and a pressure compensating vessel 31 within the casing.

The construction and arrangement of the manifold units 20 will be described in more detail with reference to the remaining Figures.

Each manifold unit consists of a single metal block 32 which has a number of galleries drilled in it. The galleries conduct hydraulic fluid from one position to another, and flow out of a particular gallery is governed by the state of a valve 34 controlling flow. In Figure 4, six individual valves 34 are shown as 34a, 34b, ... 34f.

The block 32 is located on the floor 36 of the casing 12 by two dowel pins 38 which locate in sockets 40 on the block.

Figure 5 shows an opposite side of the manifold block where passages not required in this particular configuration are closed by blanking plates 42a to 42f.

For example, indicated schematically beneath the plate 42a are the four passages in the block which are closed by the blanking plate 42a.

Hydraulic fluid enters the manifold block through the filter 30, and leaves the block through one or more of the valve outlets 46a, 46b, ... 46f.

Figure 6 shows further blanking plates 42g, 42h ... 421 on face B. Also visible in Figure 6 are the control signal connections 48 which feed the valves 46.

In Figures 7-12, internal manifold passageways are illustrated by dotted lines. The tapping holes into which the manifold valve assemblies are screwed are indicated, together with the manifold body exit ports which are numbered 50. The internal fluid bores carry reference numerals 52 and the tapped holes numerals 54. The body 20 is also provided with fixing holes 56 by which the body can be secured to the casing 12 and/or by which other components such as the filter unit 30 can be secured to the manifold body.

By constructing the manifold body so that it has exit ports on opposing faces, it is possible to greatly increase the number of wellhead valves which a single control module can control, without increasing the overall size of the module itself. Furthermore the manifold body can accommodate up to twelve valves, as shown, or the same principles could be applied to enable the body to accept a greater or a lesser number of valves, in accordance with the desired final specification.

Claims

1. A manifold arrangement for distributing hydraulic fluid in a sub-sea environment, the arrangement comprising a manifold body having fluid passages therethrough and a plurality of valves mounted on the body to control flow through the fluid passages, wherein the body has fluid exit ports on at least three different faces thereof.

2. A manifold arrangement as claimed in Claim 1, wherein the manifold body is a generally rectangular, single block of metal provided with gun-drilled intersecting bores to distribute hydraulic fluid as desired.

3. A manifold arrangement as claimed in Claim 2, wherein the block is adapted to be mounted on one end face, with the exit ports being provided on faces which are perpendicular to the mounting end face.

4. A manifold arrangement as claimed in any preceding claim, wherein a hydraulic fluid filter device is mounted on a face opposite to the mounting end face.

5. A manifold arrangement as claimed in any preceding claim, wherein the manifold arrangement is mounted within a sealed casing, the casing being intended for positioning on the sea bed and being capable of withstanding the pressures imposed on the sea bed.

6. A sub-sea control module comprising a casing having a hydraulic fluid entry point, a power supply entry point and a plurality of hydraulic fluid exit points, the casing containing a manifold arrangement as claimed in any preceding claim, for distributing hydraulic fluid from the entry point to the exit points, and an electronic control module adapted to receive signals from an external signal source and to control valves mounted on the manifold in accordance with those signals.