RU2797093C1 - Method for eliminating the consequences of accidental spills of oil and oil products in the areas of development of oil and gas fields on the sea shallow shelf - Google Patents

Abstract

FIELD: environmental protection.

SUBSTANCE: invention relates to methods of complex solutions for elimination of the consequences of accidental spills of oil and oil products in the areas of development of oil and gas fields on the sea shallow shelf. The method includes emergency response and containment of the contaminated area with booms, pollution removal, marine reclamation. The booms are laid in a reinforced concrete trough installed on the seabed in a ring around the drilling platform at a distance of at least 50 m from the edge of the platform on all sides. Every 10 m, reef structures are attached to the ears mounted in the gutter – artificial biotopes and ropes, the other end of which is fixed perpendicular to the boom section.

EFFECT: liquidation of the consequences of an emergency oil spill, increased efficiency of cleaning at the sites of oil accidents, increased recovery rate of disturbed biocenosis.

1 cl, 1 dwg

Description

Oil spills are possible at all stages of field development. Sources of oil pollution can be boreholes for various purposes (prospecting, exploration, parametric, etc.), oil fields (development wells, infield pipelines, oil preparation points for further transportation), etc. The most severe pollution occurs during exploratory drilling, when an oil reservoir is opened. In such cases, the well often begins to flow, which leads to environmental pollution with formation fluids (oil, gas condensate, formation waters with dissolved hydrocarbons). [1]

(http://agz.edu.kz/public/uploads/BIBL_RMEB/likvidasya_nefterazlivov.pdf Elimination of emergency situations in case of oil and oil products spills on water and land. Training manual).

Localization and liquidation of emergency spills of oil and oil products provides for the implementation of a multifunctional set of tasks, the implementation of various methods and the use of technical means. Regardless of the nature of an accidental oil and oil products (OOP) spill, the first measures to eliminate it should be aimed at localizing spots in order to avoid the spread of further pollution to new sites and reduce the area of pollution.

Booms are the main means of containment of OOP spills in water areas. Their purpose is to prevent oil from spreading on the water surface in the event of an accident, to reduce the concentration of oil to facilitate the cleaning process, and to divert (trawl) oil from the most environmentally vulnerable areas. [2]

(http://secuteck.ru/articles2/prom_sec/avariynie_razlivi

Oil spills: means of containment and methods of liquidation,

Pop-up booms (VBZ) are installed once for many years. After installation, air is released from them remotely, the booms lie on the ground and do not interfere with navigation. If necessary, air is remotely supplied to the boom from the berth, the booms float to the surface and acquire the desired shape on the surface. The complex, being at the bottom, does not wear out, it is ready for work around the clock in both summer and winter. The frequency of use is not limited. Pop-up booms can be installed in both fresh and sea water.

Pop-up booms (VBZ) differ in their use for emergency and working ones.

Emergency - located at the bottom and raised to the surface only in case of an accident. Each section of such a boom is equipped with inlet non-return valves and safety valves. In order to place such a boom on the ground after the liquidation of the accident, it is necessary to release gas from each section sequentially from the board of the floating craft.

Workers - pop-up booms located at the bottom and raised to protect the tanker during loading (vessel during bunkering).[3]

(https://studopedia.ru/21_23088_avariynie-bonovie-zagrazhdeniya-naduvnie.html Emergency booms (inflatable).

Various designs of booms and methods of barriers for containment of oil spills in reservoirs are known from the field of technology.

Known utility model No. 147605, published: 11/10/2014 bul. No. 31 "Pop-up boom."[4]

The utility model relates to hydraulic structures designed to enclose a section of the water surface in order to prevent the spread of oil and oil products. The barrier has an inflatable shell, consisting of sections. The sections are hermetically connected by camlock connections having holes for connecting the cavities of the sections into a single internal space. The boom has a compressor connected by a pipeline to the front end of the first section. There is a shutter to release the working pressure before flooding the barrier. The barrier with the help of stretch marks is fixed on the banks of the reservoir. At the front end of the boom there is a winch to fix this end at depth h before lifting the boom. The rear end of the fence is fixed with an anchor. To flood the barrier, the end of the last section is provided with a weight to hold this end close to the surface of the reservoir after the barrier rises.

Known invention No. 2 221 109 Published: 10.01.2004 Bull. No. 1 "Boom of variable buoyancy" [5].

The invention relates to the protection of the environment during the technical operation of the main oil product pipelines and can be used to localize and collect oil or oil product stains, including its powerful flow on a flowing reservoir, mainly a river. It is possible to use the invention around sea and river oil terminals, as well as water intake devices.

The boom barrier (BS) consists of cylindrical sections pivotally connected to each other, made of metal pipes with plugs. On each, except for the final one, nozzles are placed for connecting the cavities of the sections to the compressor and the pump for supplying water, respectively, as well as for connecting the pipelines passing through the sections to the heating device. In the upper part, symmetrically about its longitudinal axis, there are two hollow ridges located lengthwise at a distance from each other. They have a triangular profile in cross section. An inflatable cushion is fixed on the site along the entire length of the boom, in the upper part of which there are layers of thick foam rubber, to which absorbent mats are fastened. For greater stability on the wave and in storm winds, they can have ballasts attached to their lower surfaces opposite the platform or pontoons made of pipes. The cavities of the pontoons are looped with cavities (BZ).

Known invention No. 2 646 896, published: 03/12/2018, bul. No. 8 "Boom of variable buoyancy on offshore oil platforms" [6], chosen by us as a prototype.

The invention relates to the protection of the environment, namely to hydraulic structures designed to enclose a section of the water surface in order to prevent the spread of oil and oil products. A variable buoyancy boom includes a flexible pipe mounted on a bearing element, provided outside along the entire length in its upper part with two rows of comb-shaped elastic elements, and in the lower part with one row of such elements. The flexible pipe is looped and divided into separate sections. Each section contains a sealing piston made of elastic material, which completely covers the internal section of the section. One end of each section has a connection with the water mass, the other end is equipped with a fitting, to which an air-vacuum pump is connected by means of a hose

The disadvantage of the described inventions is the limited functionality that ensures the localization of an emergency release of oil and oil products into the water area and, in some cases, partial elimination, since it is impossible to completely eliminate oil pollution.

According to paragraph 8 of the "Rules for organizing measures to prevent and eliminate spills of oil and oil products on the territory of the Russian Federation" (approved by Decree of the Government of the Russian Federation of April 15, 2002 N 240), measures must be taken to eliminate the consequences of spills, while these works may be considered completed when the permissible level of residual content of oil and oil products (or products of their transformation) in soils and soils, bottom sediments of water bodies is reached [7].

(RD 52.24.609-2013 Guiding document. Organization and monitoring of the content of pollutants in bottom sediments of water bodies. Introduction date 2013-09-02).

Obviously, the stable functioning of the natural ecosystem is possible only if the conditions for the reproduction of bioresources are preserved. This condition can be met by designing artificial systems that provide the maximum speed of rehabilitation of the damaged area. The ecological balance of an ecosystem is determined by the ratio of its incoming and outgoing parts and is based on the principles of conservation of matter and energy.

The likelihood of oil spills is high, and this implies a comprehensive response and fight against oil spills by various means. Timely and high-quality fight against oil spills can significantly reduce the amount of environmental and economic damage. Serious oil spills cannot be predicted in advance, however, in the event of a spill, they must be dealt with by all possible and appropriate methods of containment and response.[8]

(https://ecoportal.su/public/zagryazn/view/601.html Oil spill containment and response.)

In the event of an emergency leakage of oil products from a drilling platform, oil that has entered the water causes a gross violation of the characteristics of the aquatic environment and adversely affects the aquatic flora and fauna. The environmental consequences in this case are difficult to take into account, since oil pollution disrupts many natural processes and relationships, significantly changes the living conditions of all types of living organisms and accumulates in biomass.

The objective of our invention is to create a method that ensures environmental safety and rehabilitation of the ecosystem in offshore oil production areas, as well as the possibility of emergency response and localization of a contaminated area in case of an emergency oil and oil products spill from a drilling platform installed on a shallow sea shelf, providing compensation measures that determine the maximum speed restoration of disturbed biocenosis.

The solution of the task is realized in the creation of a complex consisting of a chain of pop-up booms and artificial biotopes,

providing localization and elimination of pollution, purification and restoration of disturbed biocenosis.

The invention relates to the protection of the environment, and in particular to methods of complex solutions for the elimination of the consequences of accidental spills of oil and oil products in the areas of development of oil and gas fields on the sea shallow shelf.

The essence of the method is illustrated in Fig. 1. Pop-up booms (prior art designs may be used) consist of inflatable sections. The sections are hermetically connected, forming a chain (1), and have openings from one section to another, through which air is pumped alternately into all sections by the compressor in an emergency, which ensures the floating of the boom to contain the spill. The compressor is located on the drilling platform and is connected by a pipeline (2) to the front end of the first section. Its length depends on the depth at which the oil platform is installed. After the elimination of pollution for flooding, boom sections are filled with water displacing air. The booms are laid in a reinforced concrete trough (3) installed on the sea bottom in a ring around the drilling platform (4) at a distance of at least 50 m from the edge of the platform on all sides, equipped on the shallow sea shelf.

Ropes (6) and reef structures - artificial biotopes (7) are tied to the ears (5) mounted in the gutter every 10 m. The other end of the rope is perpendicularly attached to the boom section to fix the chain around the platform, its length depends on the depth at which the oil platform is installed. The biotopes consist of propylene rope collectors, the upper part of which is attached to a plastic buoy to keep the biotope upright. Bundles of polypropylene fibers and monofilaments of twisted polypropylene rope are woven into the collector, acting as an artificial substrate suitable for the settlement and life of marine organisms, which are fixed in a knot. In this case, we use an artificial biotope, patented by us. (Useful model No. 190503, published: 02.07.2019 Bull. No. 19) [9].

In the event of an emergency spill of oil products from the drilling platform, a compressor is switched on, which pumps air into the boom sections, which ensures the ascent of the boom around the oil platform, preventing the spread and spreading of the oil slick, and facilitating the elimination of the spill, carried out by any known method.

Oil spill response methods:

- chemical methods:

- physical and chemical methods (flushing, drainage, sorption);

-biological methods (bioremediation and phytoremediation);

- thermal method.

After liquidation of the spill and removal of oil stains, the compressor pumps water into the boom sections, thereby displacing air, which contributes to the sinking of the booms to the bottom, where the sections are laid by divers in a reinforced concrete bed.

But even with these methods, it is rather difficult to achieve good cleaning results at the sites of oil accidents. And no matter how carefully the liquidation of the oil spill and the removal of stains take place, a certain amount of pollution remains on the surface and over time, the products of their transformation disperse in the water column and settle to the bottom.

Artificial biotopes, fixed along the entire perimeter of the reinforced concrete bed, will continue the process of cleansing the ecosystem. Marine reclamation carried out by artificial biotopes helps to reduce the level of pollution in these areas due to biofilter foulers that settle on biotopes, ensures the conservation of biodiversity, increases the self-cleaning ability and resistance of the ecosystem to stresses caused by anthropogenic impact.

Thus, the proposed invention "Method of eliminating the consequences of accidental spills of oil and oil products in the areas of development of oil and gas fields on the sea shallow shelf" is implemented in the creation of a complex that provides emergency response and localization of the contaminated area with booms, removal of pollution, marine reclamation, aimed at protecting against deformation structures of the biocenosis and rehabilitation of the ecosystem in the areas of development of oil and gas fields on the sea shallow shelf. This will make it possible to eliminate the consequences of an accidental oil spill and create conditions for the reproduction of biological resources.

Used sources.

1. http://agz.edu.kz/public/uploads/BIBL_RMEB/likvidasya_nefterazlivov.pdf Oil and oil products spill response on water and land

2. http://secuteck.ru/articles2/prom_sec/avariynie_razlivi

Oil Spills: Means of Containment and Response Methods

3. https://studopedia.ru/21_23088_avariynie-bonovie-zagrazhdeniya-naduvnie.html

Emergency booms (inflatable)

4. Utility model No. 147605, published: 11/10/2014 bul. No. 31 "Pop-up boom."

5. Invention No. 2 221 109 Published: 10.01.2004 Bull. No. 1 "Boom of variable buoyancy"

6. Invention No. 2 646896, published: 03/12/2018, bul. No. 8 "Boom of variable buoyancy on offshore oil platforms".

7. RD 52.24.609-2013 Guiding document. Organization and monitoring of the content of pollutants in the bottom sediments of water bodies. Date of introduction 2013-09-02.

8. https://ecoportal.su/public/zagryazn/view/601.html

Localization and elimination of emergency oil spills.

9. Utility model No. 190503, published: 02.07.2019 Bull. #19

"Artificial biotope".

Claims (1)

A method for eliminating the consequences of accidental spills of oil and oil products in the areas of development of oil and gas fields on the offshore shallow water shelf, including emergency response and localization of the contaminated area with booms, removal of pollution, marine reclamation, characterized in that the booms are laid in a reinforced concrete trough installed on the sea bottom in a ring around drilling platform at a distance of at least 50 m from the edge of the platform on all sides, while reef structures are attached to the ears mounted in the gutter every 10 m - artificial biotopes and ropes, the other end of which is fixed perpendicular to the boom section.

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