RU2820362C1 - Mobile underwater storage for liquid oil products - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to the field of oil production, storage and transportation of oil and other liquid hydrocarbons on the Arctic seas shelf, and can be used for accumulation, storage and distribution of natural liquid hydrocarbons before transportation to consumer. Mobile underwater storage for liquid oil products, comprising a rigid water-permeable platform, inside which there are tanks for storage of liquid oil products, at the stern of the rigid water-permeable platform there are water-air propellers, on top of the rigid water-permeable platform there are containers for storing compressed air, intended for the operation of the water-air propellers, also on the platform there is a ballast system and compensating cylinders for controlling loading of a mobile underwater storage, facility for compressed air pumping into compressed air storage containers and mobile underwater storage control system.

EFFECT: practical possibility of independent movement of underwater storage for liquid oil products under water with observance of conditions of complete ecological and fire safety, and allows their use with special tug.

1 cl, 3 dwg

Description

DESCRIPTION OF THE INVENTION

The invention relates to the field of oil production, in particular, for the storage and transportation of oil and other liquid hydrocarbons on the shelf of the Arctic seas, and can be used for the accumulation, movement, storage and delivery of natural liquid hydrocarbons for their transportation to the consumer [B65D 88/78, E21B 43 /01].

A FLOATING UNDERWATER TANK FOR COLLECTION AND STORAGE OF OIL AND PETROLEUM PRODUCTS [RU 2021959 C1, publ. 10.30.1994] is known from the prior art, including a housing with a distribution unit and a means for attaching it to the ground, containing a flexible element. In addition, the tank is equipped with a sealed equalization tank installed in the hull with valves for filling with outboard liquid medium and ventilation and tanks of constant and variable buoyancy, while the hull is unloaded from external hydrostatic pressure, and the flexible element is elastic in terms of actuation force exceeding the buoyancy value of the submerged hull without oil, and is connected to the sea liquid filling valve.

The disadvantage of this solution is the rigid connection to the ground, and as a result, the inability to move the tank under water.

Also known from the prior art is UNDERWATER STORAGE OF OIL PRODUCTS [SU 1510290A1, publ. 04/20/2000], containing a pontoon made in the form of a sealed container with branch pipes, three product pipelines hinged on the pontoon, the central one of which is connected to the pontoon cavity, and dispensing hoses. In addition, the storage is equipped with cylindrical inserts fixed inside the pontoon with a gap relative to the bottom on two pipes for connecting the dispensing hoses, and the third pipe is made perforated on a segment located inside the pontoon, and is equipped with engagement elements fixed on the inside of the pipe forming and a spring-loaded float a valve, on the outer generatrix of which there are vertical guides for the engagement elements, with each outer product pipeline connected to a dispensing hose on the outside of the pontoon.

The disadvantage of this solution is also the rigid connection to the ground, and as a result, the inability to move the tank under water.

The closest in technical essence to the claimed solution is DEEP-WATER UNDERWATER OIL STORAGE FOR OIL PRODUCTION [CN101672176A, publ. 2010-03-17], which includes an underwater wellhead module, an underwater treatment module, an underwater oil storage module for water replacement, a deep-sea riser, a pontoon, and a shuttle oil tanker. In this case, the underwater wellhead module, the underwater treatment module and the underwater oil and water storage module are located on the seabed and connected in series by pipelines. One end of the deep-sea riser is connected to the water-oil displacement subsea oil storage module, and the other end is connected to the pontoon. A shuttle tanker moored to a pontoon while loading oil.

The main technical problem of the prototype is the inability to move the tank underwater in a horizontal plane.

The objective of the invention is to eliminate the shortcomings of the prototype.

The technical result of the invention is to provide the ability to autonomously, or with the participation of a special tug, move an underwater storage facility for liquid petroleum products under water. In addition, the technical result is to increase environmental and fire safety of transportation.

The technical result of the invention is achieved due to the fact that a mobile underwater storage facility for liquid petroleum products contains a rigid water-permeable platform that acts as a frame, inside of which tanks for storing liquid petroleum products are located, water-air propulsors are placed at the stern of the rigid water-permeable platform, and containers are placed on top of the rigid water-permeable platform for storing compressed air intended for the operation of water-air propulsors; also on the platform there is a ballast system and compensating cylinders for controlling the loading of the mobile underwater storage, a means for pumping compressed air into the compressed air storage tanks and a control system for the mobile underwater storage.

Brief description of the drawings.

In fig. Figure 1 shows a general diagram of the operation of a storage facility for liquid petroleum products.

In fig. Figure 2 shows a general view of the storage facility for liquid petroleum products.

In fig. Figure 3 shows a sectional view of a storage facility for liquid petroleum products.

The figures indicate: 1 - rigid water-permeable platform, 2 - compressed air storage tanks, 3 - water-air propulsors, 4 - means for pumping compressed air into compressed air storage tanks, 5 - air supply pipe and cable, 6 - control system for mobile underwater storage, 7 - tanks for storing liquid petroleum products, 8 - service vessel, 9 - compressor.

The need to create and use underwater storage facilities has become especially urgent in recent decades due to the difficult logistics of delivering extracted oil during the development and exploitation of Arctic fields. Underwater storage facilities at the location of the well make it possible to avoid the construction of underwater pipelines from the field to the onshore terminal (the cost of such pipelines is very high) and thus reduce the cost of transportation and increase the safety of the system at the initial stages of supplying oil to the consumer.

At the same time, the creation and operation of stationary underwater storage facilities has specific disadvantages: the construction and maintenance of such storage facilities, taking into account their maintenance, makes their operation and maintenance quite expensive, which means that their creation near wells with low oil reserves is unprofitable. And if we take into account the fact that fields with low flow rates are more common and more scattered, then a possible solution is to create mobile storage facilities that have a volume comparable to weekly or monthly production (this will allow more efficient organization of oil production and shipment to load a large tanker or stationary tank ). To fully service the logistics of a large field, an entire fleet of underwater tankers will likely be required.

A mobile underwater storage facility will be quite effective if it can transport petroleum products on a local scale and, if necessary, store the cargo in a safe place for a long time, i.e. on the way from the well to the complex collection point. Therefore, for the successful operation of an underwater storage facility, the key factors are the corrosion resistance of the shells of oil tanks and high requirements for the reliability and reliability of propulsors, their environmental and fire safety.

Based on the sum of the requirements for underwater storage, the most adequate source of movement is water-air propulsors (see patent RU 2799688 C1), and the source of energy is compressed air.

Structurally, a mobile underwater storage facility for liquid petroleum products contains a frame - that is, a rigid water-permeable platform 1, inside of which tanks for storing liquid petroleum products 7 are located; water-air propulsors 3 are located at the stern of the platform 1. The optimal number of propulsors 3 is up to twelve pieces.

On top of the rigid water-permeable platform 1 there are containers for storing compressed air 2, which is intended for the operation of water-air propulsors 3.

Also on the platform 1 there is a ballast system and compensating cylinders for controlling the loading of the mobile underwater storage (not shown in the figure), a means for pumping compressed air 4 into the tank 2 for storing compressed air, and a control system for the mobile underwater storage 6.

To service and move the underwater storage, a vessel 8 can be used, which contains a compressor 9.

The service vessel 1 is connected to the underwater storage facility via an air supply pipe and a cable 5. This connection is necessary for pumping compressed air into the compressed air storage tanks 2 located on the platform 1.

After pumping the required amount of air, vessel 1 is separated and the storage facility switches to autonomous operation mode.

In the autonomous operating mode, compressed air enters the propulsors, as a result of which the entire structure receives a continuous thrust impulse, sufficient to move it under water in a horizontal plane, and the control system 6 regulates the distribution of air among the individual ones and thereby changes the direction of the total thrust impulse in the horizontal plane. Moreover, due to the fact that only compressed air is used to move and control the storage facility, and there are no additional mechanical systems and devices, high environmental and fire safety is ensured naturally.

The control system 6 is autonomous and ensures coordination of the storage along the route based on programmed data, satellite data and/or using acoustic beacons specially installed along the route. In addition, the platform can be towed by means of a traction multifunctional pipe-cable 5 with a length of 600-900 meters, attached to a service vessel 8, made on the basis of a tug. The air supply pipe and cable 5 perform the following functions: provide towing (i.e., withstand tens of tons of force) and serve as a connecting pipe between the compressor 9 installed on the vessel 8 and the compressed air storage tanks 2.

In towing mode, autonomous control is disabled, and the thrusters operate according to the tug's commands to maintain traction and correct the direction of movement.

The ballast system and compensating cylinders are designed to control loading. Due to the fact that the specific gravity of oil products is noticeably lower than water, the filling of the soft shell after pumping out the oil must be compensated for with ballast.

From established practice and existing natural conditions, it follows that the current requirements for the general technical characteristics of an underwater storage facility are as follows: volume of transported petroleum products: 5-10 thousand tons, corridor depth for transport movement 50-80 meters, speed (average for movement at the local level) 3 -8 km/h.

Mobile storage facilities for liquid petroleum products can also be used for relatively long-term (10-20 months) underwater storage. At the same time, in unused coastal bays, an oil products warehouse can be organized in the form of a parking lot for dozens of underwater storage facilities, which can be stacked in several layers. This may be especially relevant for protecting oil from terrorist attacks from the air.

Thus, due to the fact that the mobile underwater storage facility for liquid petroleum products contains a rigid water-permeable platform that acts as a frame, inside of which are located: tanks for storing liquid petroleum products, at the stern - water-air propulsors, on top - tanks for storing compressed air intended for the operation of water-air propulsors and a device for its injection, as well as a control system for mobile underwater storage, at the bottom of the platform - a ballast system and compensating cylinders for controlling the loading of mobile underwater storage, then all this together provides the possibility of controlled autonomous movement of underwater storage for liquid petroleum products under water, subject to the requirements of reliable environmental and fire safety.

Claims (1)

A mobile underwater storage facility for liquid petroleum products contains a rigid water-permeable platform that acts as a frame, inside of which tanks for storing liquid petroleum products are located, water-air propulsors are located at the stern of the rigid water-permeable platform, and tanks for storing compressed air intended for water operation are located on top of the rigid water-permeable platform. - air propulsors, also on the platform there is a ballast system and compensating cylinders for controlling the loading of the mobile underwater storage, a means for pumping compressed air into the compressed air storage tanks and a control system for the mobile underwater storage.