Bottomless spar-type oil storage tank

Abstract

An oil storage tank installed on the seabed under a marine structure with a working tower, an incinerating tower, a heliport, an oil separator, a drilling deck, a production deck, and a bottom deck, including a inner vessel and an outer vessel which are spar-type coupled to each other, an oil storage chamber formed in the inner vessel, a permanent ballast tank provided in the lower portion between the inner and outer vessels, and permanently holding pieces of iron, orecrete, concrete, sludge, etc., a sea water ballast tank provided on a separating panel, and an air buoyancy tank provided on the tank in such a manner that the overall tank acts as a buoy and the oil storage chamber is bottomless.

What is claimed is:  
     
         1 . A bottomless spar-type oil storage tank comprising a structure of a bottomless spar, and a buoy and dual walls for solving buoyancy and ballasting problem.  
     
     
         2 . A bottomless spar-type oil storage tank comprising a structure of a bottomless spar, a buoy and dual walls for solving a buoyancy and ballasting problem, and a pliable film for preventing oil in the tank and sea water from adhering to each other.  
     
     
         3 . A bottomless spar-type oil storage tank comprising a structure of a bottomless spar, a buoy and dual walls for solving a buoyancy and ballasting problem, and an upward/downward-moving rigid bottom for preventing oil in the tank and sea water from adhering to each other.  
     
     
         4 . A bottomless spar-type oil storage tank according to  claims 1  to  3 , wherein the spar includes: 
 an inner vessel and an outer vessel spar-type coupled to each other;  
 an oil storage chamber formed in the inner vessel;  
 a permanent ballast tank provided in the lower portion between the inner and outer vessels, and permanently holding pieces of iron, orecrete, concrete, sludge, etc.;  
 a sea water ballast tank provided on a separating panel; and  
 an air buoyancy tank provided on the tank.