Procedure and the apparatus for the extraction of methane gas from the sea bottom

Abstract

The present invention is referring to a procedure and a apparatus of extraction of methane gas from the bottom of the sea, consigned to the extraction of methane gas from marine sediments found in the sea's and ocean's depthless and with which came to produce in the end, methane liquefied gas. The procedure, in accordance with the invention consists of lowering a take out enclosure to a depth of over 500 m., followed by a take out of a quantity of cryohydrate sediment from the bottom of the sea and the elevation of enclosure until is reached a level at which the water pressure and its temperature create conditions which allowed the beginning of a process of releasing of methane gas from cryohydrate crystals. The following operation is the releasing of methane from the entire quantity of take out cryohydrate, methane that is collected in a room from where is raised through a tube and captured into an enclosure and then liquefied. The remaining sediments without methane are returned to the ocean's floor by gravity. The apparatus, conform to the invention, is composed of some guiding arms B positioned crosswise, and on which a platform A is sitting and from a central anchor C at which cylindrical corp 2 are assembled by superior ends of some portion c of the mentioned arms B, some collection cages D being suspended of arms B by some ropes 5, 6, 13 and 14 help, and anchor C in which is incorporated an axial-radial bearing 33, being connected by an intermediary rope 21 at the sea bottom.

1 . Procedure of extraction of methane gas of the sea bottom, characterized by so that: in a first operation, consists of lowering of a take out enclosure to the depths of over 500 m. from the sea surface, followed by taking out a quantity of cryohydrate sediment of the bottom of the sea and lifting of the enclosure which contain the cryohydrate until reaching of a level at which the water pressure and its temperature created conditions which permit the beginning of process of releasing methane gas from cryohydrate crystals, the following operation being the releasing of entire quantity of methane gas from cryohydrate, by keeping at this level the enclosure. The methane gas being collected because difference of density between water and gas at upper side of enclosure and which then the methane is risen towards water surface trough a tube and is captured in a cryogenic system, while then liquefied and stored. The remaining sediments without methane are returned to the ocean's floor by gravity.  
     
     
         2 . Procedure of the extraction of methane gas of the sea bottom according  claim 1 , characterized by so that, the lifting of enclosure with cryohydrate is done until reaching a level at which the pressure of water is less then 47.5 barr and its temperature is more than 7 degrees Celsius.  
     
     
         3 . Procedure of the extraction of methane gas of the sea bottom, according  claim 1 , characterized by so that, the halting of enclosure's ascent at a level at which the methane's release process can take place is ordered by the signal of presence of a pocket of methane gas collected at the upper part of the enclosure.  
     
     
         4 . Apparatus of the extraction of methane gas of the sea bottom characterized by so that, is composed from some guiding arms B, positioned in crosswise and on which a platform A is sitting and from a central anchor C at which cylindrical corp  2  are assembled through superior ends of c portions the mentioned arms B, some cages D being suspended on arms B with the help of ropes  5 ,  6 ,  13  and  14  while anchor C being connected through a rope  21  to the sea bottom.  
     
     
         5 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 4 , characterized by so that, the work platform A is of a square shape and has in the central part an opening a also square, on it being placed some electrical trolleys  7 ,  8 ,  11  and  12 , positioned in the zones of over the arms B, and is provided with a cryogenic system for liquefaction and depositing of the methane gas  9  and with a group electrogen Diesel  10  and along with the sides of opening a collection conduit  16  connected to the cryogenic system  9 .  
     
     
         6 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 4 , characterized by so that, the guiding arms B being provided with a portion b horizontally which extends until the opening zone a followed by a inclined portion c which exceed in high the platform A surface, their disposition being radial and symmetric towards the anchor C while their supporting to the sea surface being achieved by the help of floating caissons  3 .  
     
     
         7 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 6 , characterized by so that, on the longerons of portions b and c of arms B guide from one end to the other some rolls blocks  4  on which rolling the ropes  5  and  6  and which permit the modification of the radial position of cages D and the support of flexible conduits  15  with the help of ropes  13  and respective  14 , the circular movement of cages D is achieved by the help of some propellers  17 ,  18 ,  19  and  20  which are electrical powered and placed at the ends of arms B and which allow the rotation of entire ensemble.  
     
     
         8 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 4 , characterized by so that, under the central anchor C is positioned a hoist  23  with which is making the stretching of rope  21  until can be reached the submerged under sea level of arms B. The inferior end of mentioned rope  21  being anchored by some counterweights  22 .  
     
     
         9 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 4 , characterized by so that, the mentioned cages D are provided a collected room  24  parallelepiped, continued at superior part with a collecting bell  25  of pyramidal shape and at the inferior part with some cylindrical sectors  26  and  27 , the exterior walls of room  24  being equipped with some rolls wills  28  and  29  over which are passing some ends of rope  5  and then tied by some arms  30  connected with sectors  26  and  27 .  
     
     
         10 . An apparatus of the extraction of methane gas of the sea bottom, according  claim 9 , characterized by so that, the cylindrical sectors  26  and  27  are joined to room  24  and can be rotated with the help of some springs e and ropes  5  at 90 degrees around of a horizontal axis, so that when they are opened penetrate inside of room  24  and are provided at the inferior half with some portions perforated g.  
     
     
         11 . An apparatus of extraction of methane gas of the sea bottom, according  claim 9 , characterized by so that, the collected bell  25  is equipped at upper part with a sleeve h at which is connected the inferior end of conduit  15  and at interior with a gas detector  34 .