RU2263248C2 - Method of and device for storing natural gas - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention relates to method of storing natural gas for satisfying peak requirements. According to invention, hermetic sleeve, diameter 10-12 m and 400-600 m long, is made of sheet reinforced polyethylene, thickness 0.3-0.5 mm. High-pressure reinforced hose is fitted at one end of sleeve. Flattened sleeve is lowered to bottom of sea or lake to depth of 2-4 km, with laying of high-pressure hose along bottom to beach or floating station. Sleeve is covered by rope net, and granite stones are placed at sides to equalize buoyancy force. Gas under pressure of 200-400 atm is pumped into sleeve to turn it into cylindrical reservoir-storage, capacity of -60 thousand cubic meters. Reservoir is enclosed by rope net to prevent floating up. Gas is consumed from storage by natural forcing by bottom pressure of water. Proposed device for storing natural gas consists of compressing and transfer station, high-pressure pipeline, elastic reservoir, rope net and granite ballast. Compressing station is installed on the beach or afloat on sea or lake surface and is connected at bottom by high-pressure pipeline with elastic storage-reservoir enclosed by rope net and arranged at depth of 2-4 km.

EFFECT: possibility of storing gas compressed to 400 atm in modular thin walled reservoirs.

3 cl, 1 dwg

Description

The invention relates to the gas industry, in particular to a technique for storing natural gas to meet peak gas needs.

Peak needs, for example, in Russia are 60-70 billion m ³ per year. Meeting such needs with a sharp increase in gas production is associated with enormous difficulties associated with an increase in the capacity of gas production and gas pipeline equipment.

At the same time, in the summer months, when gas consumption decreases, part of the production could be pumped into underground gas storages (UGS). And so it is done.

Today in Russia about 30% of the total gas produced is used from gas storage facilities. All this speaks of the urgent need to develop natural gas storage technology.

Peak gas fuel needs arise for the following main reasons:

- seasonal unevenness in gas consumption;

- abnormally cold winters;

- emergency situations on gas pipelines;

- ensuring the reliability of export supplies;

- Delay in the commissioning of new capacities.

Three methods of gas storage are known:

1. Compressed storage

a) in high-pressure cylinders (up to 250 atm).

Disadvantage: for large storages it is impractical due to complexity, bulkyness and explosiveness.

b) in underground gas storage facilities (aquifers, in depleted gas and gas condensate deposits, in salt caverns, in porous layers of sandstone).

Disadvantages:

- the complexity of the wellhead equipment;

- diffusion gas loss;

- violation of water-salt metabolism in groundwater;

- the need to drill multiple wells for uniform pumping of gas.

2. Storage in a liquefied state in cryogenic tanks.

Disadvantages:

- the need to maintain the temperature at the level of - 82 ° C and pressure of about 50 atm;

- the high cost and complexity of refrigeration units.

3. Storage in an adsorbed state.

This type of gas storage has been developing in recent years based on the use of solid sorbents: intermetallic compounds, activated carbons, titanium oxide, etc.

Disadvantage: very low dynamic capacity relative to methane (not more than 2.5% mass).

The objective of the invention is to find a way to hold compressed up to 400 atm of natural gas in modular thin-walled containers with a volume of several tens of thousands of cubic meters.

The problem is solved by creating deep underwater storage of natural gas, in which the pressure drop between the gas and the surrounding water storage is close to zero, and the Archimedean force is balanced by the corresponding ballast.

This is the technical result of the invention. The prototype was not found, so the application is executed as a pioneering invention.

The essence of the method lies in the fact that they take a thin (0.3-0.5 mm) sheet reinforced high-pressure polyethylene and make a sealed “stocking” of it with a diameter of 10-20 meters and a length of 400-600 meters, at one end of which is installed a reinforced high-pressure hose several tens of kilometers long, lower this “flattened” stocking to the bottom of the sea or lake to 2-4 kilometers. Laying a high-pressure hose along the bottom to a coastal or floating gas compression or pumping station, cover the “stocking” with a wire rope, and granite stones are poured from the sides in the amount necessary to balance the Archimedean force pushing the “stocking” onto the surface of the water area; they pump gas at a pressure of 200-400 atm into a “stocking”, turning it into a cylindrical storage tank with a volume of 30-60 thousand cubic meters, while frame the tank with a wire rope that keeps the tank from floating; they consume gas from such a storage facility by naturally squeezing it onto the surface with bottom water pressure.

A diagram of a device for implementing the proposed method for storing natural gas is shown in the drawing.

The gas storage device consists of the following elements: 1 - compression and pumping station, 2 - high pressure pipeline, 3 - thin-walled elastic tank, 4 - wire rope mesh, 5 - granite ballast, while the compression and pumping station is installed on the beach or afloat or lake 6 and is connected by a high-pressure pipeline laid along the bottom with an elastic storage tank located at a depth of 2-4 thousand meters, framed by a cable network, which can prevent the storage tank from floating under the by archimedean force.

The device operates as follows.

With the help of station 1, natural gas is pumped into an elastic storage tank 3 to a pressure of 200-400 atm, while the flattened tank at first takes the form of a cylinder with a volume of several tens of thousands of cubic meters and rests on top of a cable net 4 that holds the tank 3 from floating. When gas is consumed from the storage facility, it is supplied with natural gas pressure of 200-400 atm via pipeline 2 to station 1 and then through the gas pipeline to the consumer.

Example (calculated)

They take a manufactured elastic tank with a diameter of 10 meters and a length of 400 meters, place it on the bottom of a deep (4 km) water area and fill it with natural gas to a pressure of 400 atm, while the pressure inside the tank is equal to its pressure from the outside. When straightening, the capacity takes the form of a cylinder with a volume of 32,000 m ³ and rests on a cable wall 4.

The specific gravity of methane at a pressure of 400 atm is 304 kg / m ³ , and the capacity will contain 32,000 · 304 = 9,728,000 kg ~ 9,730 tons of methane. The specific gravity of methane at normal pressure is 0.717 kg / m ³ , so the stored gas supply will be 9,728,000: 0.717 = 13567642 m ³ or about 14 million m ³ .

The cable net keeps the storage tank from floating under the influence of the Archimedean force equal to 32 thousand tons. This force is maintained by a wire mesh, consisting of 3200 steel cables transverse with respect to the storage tank, each with a diameter of 10 mm, the distance between which is 0.25 m. The longitudinal components of the wire mesh are made of synthetic tape. The total mass of granite stones should be 40,000 tons.

The storage does not require maintenance at a depth and ensures gas consumption without the use of compressor stations, since the gas supply pressure is constant at 400 atm, which allows the use of small-diameter hoses.

It is of interest to use such storages in subsea natural gas fields.

Claims (2)

1. A method of storing natural gas in an underwater storage facility is that they take reinforced polyethylene sheet with a thickness of 0.3-0.5 mm and make a sealed “stocking” of it with a diameter of 10-12 m and a length of 400-600 m, on one of the ends of which a reinforced high-pressure hose is installed, a flattened stocking is lowered to the bottom of the sea or lake to 2-4 km, laying a high-pressure hose along the bottom to the coastal or floating station, cover the “stocking” with a wire rope, and granite stones are poured from the sides, in an amount necessary to balance a rhimedova force pushing the "stocking" to the surface of the water area; gas is pumped into the “stocking” at a pressure of 200-400 atm, turning it into a cylindrical tank - a storage with a volume of 30-60 thousand cubic meters, while the tank is framed with a wire rope that keeps the tank from floating; they consume gas from such a storage facility by naturally squeezing it onto the surface with bottom water pressure. 2. A device for storing natural gas, consisting of a compression and pumping station, a high pressure pipeline, an elastic tank, wire rope and granite ballast, while the compression station is installed on the shore or afloat of the sea or lake and connected along the bottom by a high pressure pipeline to the at a depth of 2-4 thousand meters, an elastic storage tank, framed by a cable mesh, which has the ability to prevent the emergence of storage tanks under the influence of Archimedean force.