Safety Valves
Copyright 2007,
, All rights reserved
Safety Valves in Well Completion
Surface Safety Valve - SSV

Automatic fail-safe close valve installed at the Upper Master
Valve of the x-mas tree

A positive shut-off flow in case of
– line leaks
– process upsets in the surface facility
– emergency shutdown.
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Safety Valves in Well Completion
SubSurface Safety Valve - SSSV

A valve installed in the tubing down the well.

When activated it stops well flow.

Valve usually activated in combination with Surface Safety
Valve
Used for Emergency Only
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SubSurface Safety Valves - SSSV
Application (1)

Why Install?
– Protect people, property and the environment in case of
blowout from sabotage or human error, collision, equipment
failure, fire or leaks

Factors determining whether to install?
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–
Copyright 2007,
Location and types of wells
Government legislation
effect of blowout on people and the environment
damage to the producing reservoir
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SubSurface Safety Valves - SSSV
Application (2)

Which type of wells require SSSV?
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–
–
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offshore flowing oil and gas production wells
offshore wells gas injection wells capable of flow
onshore gas producing and injection wells
onshore flowing sour (H2S) oil/gas wells
wells in earthquake-prone zones
Certain onshore oil wells
• near major roads and or near populated areas
• near environmental sensitive areas
• near security sensitive areas
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Tubing Safety Valves
Functional requirements

Flow barrier in the tubing when required.

Fail-safe closing at a pre-determined condition or command

To withstand the maximum reservoir pressure in closed
position

Minimum pressure drop in during production

In closed-position, pump through capability
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Subsurface Safety Valves - SSSV
Application (3)
Tubing Safety Valves

SC-SSSV - Surface Controlled SubSurface Safety Valve:
– controlled from the surface
– installed and retrievable by wireline
– installed as an integral part of the tubing

WR SC-SSSV
TR SC-SSSV
SSC-SSSV - SubSurface Controlled SubSurface Safety
Valve (Storm Choke)
– actuated by the flow characteristics of the well
– installed by wireline
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SC-SSSV Wireline Retrievable type
Control line
WR SC-SSSV
seals
Landing nipple
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SC-SSSV Tubing Retrievable type
Flapper open
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Flapper closed
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Tubing Retrievable SC-SSSV

Features
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
integral part of tubing
no restriction in flow path ID
flapper shut off
robust design
equalizing while opening
lock open option
WR-SC-SSSV can be installed as backup
Note: valve sensitive for tubing loads
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SSSV Setting Depth (3)
Recommended minimum setting depth

offshore
– 50 meter below the deepest pile penetration

onshore
– 100 meter below ground level
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