Patent Application
20110000546
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The field of this invention of that of the delivery of natural gas from a location offshore to a market on land, where the distances are not amenable to the laying of pipelines. This market is presently served by compressed natural gas ships or the gas is called stranded or is simply flared because it is not economic to produce by either pipelines or compressed natural gas ships.
Compressed natural gas ships are constructed of a series of high pressure tanks which attempt to transport gas economically by transporting a maximum amount of gas by increasing the density by a combination of pressure (i.e. 1000 p.s.i.) and reduced temperature (i.e. −40 degrees F. or C.).
As one might imagine building a ship loaded with 1000 p.s.i. tanks and refrigerating gas to −40 degrees F. or C. is expensive.
As the ships for transport are very expensive, the compressed natural gas must be immediately offloaded into comparable expensive receiving facilities. The cost of implementing a system to do this will cost something in excess of 1 billion dollars.
There are hundreds of islands especially, in the Indonesian area, which need to have a ready power supply to support development, but which cannot support a billion dollar investment. They would be immensely assisted by a ready supply of energy which could be easily turned into heat and electricity.
The object of this invention is to provide a method of transporting natural gas without the expense of constructing high pressure tanks.
A second object of the present invention is to provide a method of transporting gas without the expense of refrigerating the gas to subzero temperatures.
A third object of the present invention is to provide a method of transporting gas without the expense of receiving facilities.
The subsea tanker 2 is a depth 28 below the surface of the ocean 30. The gas bag 16 is not a pressure vessel, but rather a rubber sack. If the depth 28 is approximately 537 feet and the pressure gradient of seawater is 0.465 p.s.i./ft. The pressure of any gas in the bag is approximately 250 p.s.i.
Delivery of gas to a home is 0.2 p.s.i., so one cubic foot of gas in the subsea tanker at a 250 foot depth will yield (250+14.7)/(0.2+14.7)=17.76 cubic feet of gas to the end user.
It is important that the subsea tanker be kept near the depth 28 so that when the gas is charged in the gas bag 16, it will remain at that size. When the gas bag if fully charged, it is important that the subsea tanker 2 remains heavy in water and stays at that depth.
It should be noted that as the subsea tanker 2 is mostly a steel frame 8, a gas bag 16, and a couple of connectors it is relatively inexpensive in comparison to alternate styles of manufacture.
If it is allowed to go to a greater depth, it will further compress the gas, with the only actual effect being that it will become heavier. If it is allowed to come closer to the surface, the gas bag can expand and burst the steel cage frame 8. In doing that the gas load will be lost and the damaged subsea tanker 2 will sink to the bottom of the ocean.
Referring now to
Referring now to
Propellers 36 and thrusters 38 can be provided on the subsea tanker 2 to move the subsea tanker 2 through the water and assist in docking operations.
Referring now to
Referring now to
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.
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