SUB SURFACE SAFETY VALVE

Abstract

According to the present invention, there is provided a sub surface safety valve in a well system comprising an upper support means, a sub surface safety valve, a sealing means that seals against the inside of the production path and a bore through the sub surface safety valve and sealing means which connects to an annular inlet beneath the sealing means and an annular outlet above the sub surface safety valve.

Description

This invention relates to Sub surface Safety Valves that can he deployed in a well bore.

Sub Surface Safety Valves (SSSVs) are provided in well bores to close the production tubing and prevent production fluid rising in the event of an emergency. They are typically provided with male and female threads at either end and incorporated into the completion string. If the SSSV malfunctions, a workover is required to replace the completion string.

SSSVs can also be deployed on a retrievable wireline. Any tools deployed in the completion bore must be retrieved before the wireline retreivable SSSV is deployed.

It is an objective of this invention to be able to provide a SSSV system which reduces the disadvantages of the above systems.

According to the present invention, there is provided a sub surface safety valve in a well system comprising

• • an upper support means
  • a sub surface safety valve
  • a sealing means that seals against the inside of the production path
  • and a bore through the sub surface safety valve and sealing means which connects to an annular inlet beneath the sealing means and an annular outlet above the sub surface safety valve.

The following figures will he used to describe embodiments of the invention.

FIG. 1 is a side view of a section of the well from surface to total depth, showing the SSSV, and

FIG. 2 is a cross sectional view the SSSV and casing.

Referring to FIG. 1, an SSSV assembly 10 comprises an SSSV 12, a packer 14, and a power cable 16. The power cable is suitable for three phase power, and comprises three steel core strands each having a copper cladding, bound in insulating layers, as described in copending application PCT/GB2009/051535. The steel core is of the power cable 16 of a sufficient diameter to support both the power cable's own weight, and that of the SSSV assembly 10, whilst the copper cladding is sufficiently thick to carry a high voltage.

The end of the power cable 16 is attached to an upper connector 18, where copper cladding portions of conductive contacts in the upper connector 18, and the steel cores of the power cable 16 are secured to gripping elements incorporated in the a upper connector 18. A hydraulic line (not here shown) to control the SSSV 12 is banded along the length of the power line 16, and extends past the connector 18 to the SSSV itself.

The upper connector 18 is in turn connected to an upper outlet section 22. The SSSV assembly 10 has a central bore 30 running most of the length of the assembly. Part of the bore 30 is included in outlet section 22, and is in fluid communication with the annulas above the packer 14 via outlet 23.

The SSSV 12 is attached to the lower end of the outlet section 22. The bore 30 extends through the whole length of the SSSV 12. The SSSV 12 includes a flapper valve 32 held by a spring 31 as is known in the art.

The lower end of the SSSV 12 is attached to a packer 14. The packer 14 includes energisable seals 34 which seal against the inner surface of the well casing 20. The bore 30 also extends along the packer 14, and is in fluid communication with the annular below the packer 14 via inlets 33 situated at the bottom of the packer.

A lower connector 26 is attached to the bottom of the packer 14. The lower connector 26 has a similar cable termination to the upper connector 18, with a three strand steel core, copper clad, cable 17 hanging from the lower connector and having mechanical and electrical connection with the cable conductors in the same mariner as the upper connector 18. The upper connector 18 and the lower connector 26 have bulk heads 19 and 17 respectively, which radially protrude from the central axis of the SSSV assembly 10. Referring also to FIG. 2, steel tubes 36, 37, 38 extend from the bulkhead 19, past the upper outlet section 22 and SSSV 12, and down through the wall of the packer 14, emerging below the packer to enter the bulkhead 17. The steel tubes 36, 37, 38 are sealed against well fluids at the bulkhead, and may conveniently extend through the upper connector 18 and lower connector 26 to near the region the cables 16 and 17 respectively terminate with the connectors. The conductive contacts of the upper and lower connectors 18, 26 connect with conductors that extend through the length of the steel tubes 36, 37, 38.

The SSSV assembly 10 is deployed in the casing 20 by being lowered to cable 16 until the packer 14 is in the desired position. The packer 14 is then activated, either automatically, or for example by a control signal from the surface through a decated control line, or a signal multiplexed on the SSSV control line. During normal production, well fluids may flow up through the inlets 33, along the bore 30 through the packer 14, SSSV 12 and the upper outlet section 22, before flowing through the outlets 23, and thence flowing up through the well casing 20.

Activation of the SSSV 12 causes flapper valve 32 to close, which prevents any flow past the SSSV assembly 10.

The lower cable 17, like the upper cable 16, is strong enough to support its own weight, and to additionally support tools, and is sufficiently conductive to carry a high voltage. This means that the SSSV assembly 10 may be installed in a well together with for example an electric submersible pump, powered by and suspended via cables 16 and 17. Deploying an SSSV assembly together with a tool allows much greater functionality, and dispensinses with having to remove a tool deployed without an SSSV in order to separately deploy an SSSV.

Claims

1. A sub surface safety valve in a well system comprising

an upper support means

a sub surface safety valve

a sealing means that seals against an inside of a production path

and a bore through the sub surface safety valve and sealing means which connects to an annular inlet beneath the sealing means and an annular outlet above the sub surface safety valve.

2. A sub surface safety valve system according to claim 1 wherein a lower power cable hangs from a packer down the well, the lower power cable being conductively connected to an upper power connector.

3. A sub surface safety valve system according to claim 1 wherein a lower power cable includes a support means.

4. A sub surface safety valve system according to claim 2 wherein the lower power cable includes a support means.

5. A sub surface safety valve system according claim 1 wherein an upper power cable includes conductors that provide a support means.

6. A sub surface safety valve system according claim 2 wherein an upper power cable includes conductors that provide a support means.

7. A sub surface safety valve system according claim 3 wherein an upper power cable includes conductors that also provide the support means.

8. A sub surface safety valve system according to claim 1 wherein a lower power cable includes conductors that provide a support means.

9. A sub surface safety valve system according to claim 2 wherein the lower power cable includes conductors that provide a support means.

10. A sub surface safety valve system according to claim 3 wherein a lower power cable includes conductors that provide a support means.

11. A sub surface safety valve system according to claim 5 wherein a lower power cable includes conductors that also provide a support means.

12. A sub surface safety valve system according to claim 2 wherein an upper power cable and lower power cable are connected via at least one metal tube that passes through and is sealed against the packer.

13. A sub surface safety valve system according to claim 3 wherein an upper power cable and the lower power cable are connected via at least one metal tube that passes through and is sealed against the packer.

14. A sub surface safety valve system according to claim 5 wherein the upper power cable and a lower power cable are connected via at least one metal tube that passes through and is sealed against a packer.

15. A sub surface safety valve system according to claim 8 wherein an upper power cable and the lower power cable are connected via at least one metal tube that passes through and is sealed against a packer.