Handling of hydrocarbons and equipment of an offshore platform
AssigneeEquinor Energy AS
InventorsBjarne Alexander SOLBERG, Magne BJØRKHAUG, Dagfinn KRØGER
Life of this patent
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Abstract
A method for handling of hydrocarbons on an offshore platform 14, 16 includes the absence of emergency depressurisation for a fire. The method comprises: arranging the platform 14, 16 such that there is no mechanism for emergency depressurisation of a hydrocarbon inventory of the platform 14, 16 in the event of a fire; restricting the size of the platform 14, 16 such that evacuation of personnel can be achieved prior to escalation of a fire due to the lack of emergency depressurisation; and permitting a fire to escalate by combustion of the hydrocarbon inventory after evacuation of the personnel.
Claims26
A method for handling of hydrocarbons on an offshore platform, the method comprising:
- arranging the platform such that there is no mechanism for emergency depressurisation of a hydrocarbon inventory of the platform in the event of a fire;
- restricting the size of the platform such that evacuation of personnel can be achieved prior to escalation of a fire due to the lack of emergency depressurisation;
- and
- permitting a fire to escalate by combustion of the hydrocarbon inventory after evacuation of the personnel.
A method as claimed in any preceding claim, comprising using of isolation valves at appropriate locations, with these isolation valves being arranged to isolate the hydrocarbon inventory of the platform in the event of a fire.
A method as claimed in any preceding claim, wherein the platform has a restricted size such that evacuation of personnel can be achieved within an evacuation time that is at most 15 minutes.
A method as claimed in any preceding claim, including determining a maximum permitted evacuation time based on an estimate of the expected time for escalation of the fire, and then using this time to determine what size of platform can be permitted in combination with the absence of emergency depressurisation.
A method as claimed in any preceding claim, comprising assessing evacuation time and/or the length of the route for all evacuation routes, and adjusting the layout and/or size of the platform in order to reduce the evacuation time such that evacuation of personnel can be achieved prior to escalation of a fire due to the lack of emergency depressurisation.
A method as claimed in any preceding claim, wherein the platform has five decks or fewer.
A method as claimed in any preceding claim, wherein the vertical extent between the uppermost deck and the deck from which personnel may exit the platform is at most 40 m,
A method as claimed in any preceding claim, wherein all decks of the platform have a maximum length and/or width of less than 30 m.
A method as claimed in any preceding claim, wherein the platform is an unmanned platform with no permanent personnel.
A method as claimed in any preceding claim, wherein the platform is an unmanned platform and has no provision of facilities for personnel to stay on the platform, for example there may be no shelters for personnel, no toilet facilities, no drinking water, no personnel operated communications equipment, no heli-deck and/or no lifeboat.
A method as claimed in any preceding claim, wherein the platform is an unmanned platform and requires personnel to be present for fewer than 10,000 maintenance hours per year.
A method as claimed in any preceding claim, comprising optimising fire protection for the platform by:
- arranging the platform to have an evacuation time of at most 15 minutes or less using one or more evacuation route(s) via a gangway or bridge allowing personnel to escape to a vessel or to another platform;
- determining a maximum evacuation time for the platform;
- assessing the risk to personnel using the evacuation route(s) in accordance with the determined maximum evacuation time in the event of a fire;
- and providing passive fire protection to equipment and/or piping on the platform in order to prevent escalation of the fire that would create a risk to personnel on the evacuation route(s) during the determined evacuation time.
A platform for an offshore oil and gas installation, the platform comprising:
- equipment and piping associated with the oil and gas installation;
- a hydrocarbon inventory including hydrocarbons in the equipment and piping;
- and
- no mechanism for emergency depressurisation of a hydrocarbon inventory of the platform in the event of a fire;
- wherein the size of the platform is restricted such that evacuation of personnel can be achieved prior to escalation of a fire due to the lack of emergency depressurisation;
- and
- the platform is arranged to permit a fire to escalate by combustion of the hydrocarbon inventory after evacuation of the personnel.
Dependencies are inferred from the claim text.