Method for blocking outflow of petroleum or the like due to damage to subsea petroleum well stell pipe or the like

Abstract

The present invention relates to blocking a flow of crude oil or natural gas from a steel pipe for extracting the oil or the like that has been installed in the sea when the steel pipe is broken. When damage occurs to a steel pipe 4 for petroleum or natural gas well that has been installed in the sea, in order to send magnetic particles 21 or the like into the seafloor through an carrying pipe 6 that has been installed and suspended inside the steel pipe 4, the outflow of petroleum or the like coming from a lower portion of the carrying pipe 6 is blocked by a gate valve 20 provided at a lower portion of a feeding equipment 12 for feeding magnetic particles or the like attached to an upper opening 7 of the carrying pipe 6. After that, pressurized water is injected into a housing 14 accommodating magnetic particles or the like of the feeding equipment 12 to sweep the magnetic particles 21 or the like in the housing 14 into the carrying pipe 6 and drop the magnetic particles 21 or the like to the lower end of the carrying pipe 6. The magnetic particles 21 or the like are magnetically adhered to an inner surface of the steel pipe 4 so that the magnetic particles 21 or the like form a mass, suppressing the outflow of petroleum or natural gas. As a result, mortar or concrete 27 can be injected to block the outflow of petroleum or the like.

1 . A method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like, the method comprising:
 when a steel pipe for petroleum or natural gas well that has been installed in the sea is damaged, in order to send magnetic particles or the like into the seafloor through an carrying pipe that has been installed and suspended inside the steel pipe, blocking an outflow of petroleum or the like coming from a lower portion of the carrying pipe by a gate valve provided at a lower portion of a feeding equipment for feeding magnetic particles or the like attached to an upper opening of the carrying pipe;   after the outflow of petroleum or the like has been blocked, simultaneously opening a switching valve provided at an upper portion of the feeding equipment for feeding magnetic particles or the like and the gate valve, whereby pressurized water is injected into a housing accommodating magnetic particles or the like and provided in a rotary disk  13  to sweep the magnetic particles or the like in the housing into the carrying pipe and drop the magnetic particles or the like to a lower end of the carrying pipe, and the magnetic particles or the like move along the flow of petroleum or the like in the steel pipe, reach a conical metal mesh attached to the carrying pipe, are blocked up by the conical metal mesh and magnetically adhere to an inner surface of the steel pipe, and a resulting adherent layer gradually grows downward so that the magnetic particles or the like reach a circular mesh plate provided at a tip portion of the carrying pipe, fill inside of the steel pipe and form a mass due to magnetic force, suppressing the outflow of petroleum or natural gas; and   after the outflow of petroleum or natural gas has been suppressed, injecting mortar, concrete or the like from the upper opening of the carrying pipe and curing the mortar, concrete or the like.   
     
     
         2 . The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to  claim 1 , comprising:
 providing a non-magnetic receiving frame including several compartments in the housing of the feeding equipment for feeding magnetic particles or the like, placing the magnetic particles in the compartments, and causing the magnetic particles in the compartments to simultaneously flow into sections of the carrying pipe by the pressurized water, the sections being formed by dividing the carrying pipe into the same number as the compartments by a partition.   
     
     
         3 . The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to  claim 1 , comprising:
 in order to prevent the carrying pipe from breaking at the same time when the steel pipe is broken, using a steel wire rope-reinforced polyethylene carrying pipe in which a plurality of flexible steel wire ropes are circumferentially disposed and buried inside a wall of the polyethylene pipe and each extends in an axial direction thereof, and that is capable of sinking in the sea due to weight of the steel wire ropes, as the carrying pipe.   
     
     
         4 . The method for blocking an outflow of petroleum or the like due to damage to a subsea petroleum well steel pipe or the like according to  claim 2 , comprising:
 in order to prevent the carrying pipe from breaking at the same time when the steel pipe is broken, using a steel wire rope-reinforced polyethylene carrying pipe in which a plurality of flexible steel wire ropes are circumferentially disposed and buried inside a wall of the polyethylene pipe and each extends in an axial direction thereof, and that is capable of sinking in the sea due to weight of the steel wire ropes, as the carrying pipe.