RU2180305C2 - Complex for natural gas-field development - Google Patents

Abstract

FIELD: shipbuilding; complexes for off-shore and near-shore gas fields or arctic sea shelf and other regions functioning under ice and difficult weather conditions and at deep depths. SUBSTANCE: proposed complex includes marine platform for natural gas recovery, chemical technological system of platform preparation units, chemical technological system for production of liquid product, liquefied natural gas, for example; this platform is mainly underwater-based platform; platform is also provided with compressor station, storage with heat-exchange apparatus for subcooling liquid product with cooling agent and transport carrier vessels for transfer of liquid products for export and home market. EFFECT: intensification of offshore gas-field development, large-scale delivery of liquid products (liquefied natural gas, methanol) by means of highly efficient equipment; improved labor conditions for personnel. 6 cl, 5 dwg

Description

 The invention relates to complexes for commercial development of offshore and coastal gas deposits of the shelf of the Arctic seas, other regions, operating in ice and difficult meteorological conditions and at great depths of the seas.

 A well-known complex commercial development of offshore gas fields of the shelf of the Arctic seas, a device diagram of which is depicted in the description of the invention to the patent of the Russian Federation 2014243, published on 15.06.94, Bull. 11, including a unit for the selection and primary processing of the extracted product, a system of pipeline transport of dry GHG to the consumer along the seabed to the coast.

 This scheme of a complex for the development of deep-sea marine gas fields is less dependent on the ice situation and the influence of external factors (meteorological, climatic, wave), but is characterized by low reliability and complexity of laying a pipeline along a rocky bottom with peaked elements of its relief, as well as the difficulty of restoration ( repair) of the deep-water section of the pipeline route and high material costs during implementation, as well as the inability to commission the complex queues and a large amount of minimum starting capital.

 The closest in technical essence and the totality of features to the claimed complex is a field commercial development complex of GHG deposits in the sea (see German patent 3200958, 63 V 27/34, 25/16, Berger Eqinhard, 01/14/82), including a marine stationary platform ( SME) and the installed chemical-technological system (CTS) of GHG preparation units, CTS of liquid product units, the gas pipeline system for supplying dry GHG to the CTS of liquid product units from the CGT of GHG preparation units and at least one transport vessel - a product carrier for transporting a liquid product to a consumer, for example, in spherical tanks located on its board.

 The disadvantages of the complex, selected as a prototype, are the inefficient use of installations for the production of a liquid product (simple installations in flight with the product on board the vessel and empty for a long time), the duration of loading the vessel with a liquid product, the inability to process GHGs, for example, to methanol or ammonia and other liquid products due to the limited volume of the vessel and its displacement, the need for the crew to master several professions, the duration of the procedure for launching liquid production facilities of the product, poor conditions of work and rest, the inapplicability of the shift method of work and the inability to backup systems produce liquid product.

 The essence of the invention is to solve the problem of developing offshore and coastal GHG deposits in the shortest possible time using the minimum available means created on the basis of the modern shipbuilding industry by using serial production of liquid products in or near gas production and placing them in floating subsea-based plants designed for shelf conditions Arctic.

When carrying out the invention, intensification of the commercial development of offshore and coastal GHG fields is achieved, the supply of produced liquid products, such as liquefied natural gas (LNG), methanol, directly from the fields for export to Europe and the domestic market in large volumes up to 300 billion m ³ GHG per year by 2005, the use of smaller product vessels and more efficiently, simplification of their construction in shipyards, reduction of costs for the production of liquid products and their delivery to the consumer, including due to it is necessary to transport them in a supercooled state, to improve working conditions, life and leisure by using the shift method of staff work.

When carrying out the invention with respect to an analogue (this comparison is more relevant), for example, the supply of dry GHGs via the Yamal-Western Europe gas trunk line, for example, 50 billion m ³ GHGs per year for 30 years over a distance of 5 thousand km, a reduction is achieved material costs from $ 80 billion to $ 10 billion.

With large-scale deliveries of GHGs to Europe to 300 billion m ³ per year by 2005 (192 billion m ³ in 1996), losses are reduced in the amount of 12 ... 15 billion US dollars annually.

When carrying out the invention in relation to the prototype, a solution to the following especially important problems is achieved:
1. more efficient use of land by the land user, its return to the market,
2. deployment of GHG processing facilities at the gas production site,
3. the possibility of using the gas pipeline route as a means of solving political and other problems in the region is excluded,
4. The problems of environmental concern (ozone depletion, greenhouse effect) are mitigated,
5. reducing costs, payback periods, lower starting capital, the ability to enter the field in queues, mobility of field development.

 The proposed complex for field development of GHG deposits, including a small and medium-sized sea or offshore floating drilling rig (MPBU) and a chemical-technological system (GTS) of GHG preparation units installed on it, CGC of liquid product units from GCG of GHG preparation units and at least one transport vessel - a product carrier for transporting a liquid product to a consumer, for example, in spherical tanks located on its side, is characterized in that at least one additional vessel, mainly deep bin-based with the possibility of fixing it at a depth in the working position, for example, through a system of winches, crossing a water mirror and / or ice cover, solid or broken, on board of which at least one XTC of units for producing a liquid product, for example liquefied natural gas, is placed (LNG), methanol and other products, is connected to the HTS of the preparation of natural gas through a flexible system of dry GHG supply pipelines, made, for example, in the form of a system of interconnected spherical joints, by a system of flexible piping with a liquid product tank, such as a spherical shape, located on board the at least one transport vessel-produktovode or surfaced submarine.

 At least one storage facility for a liquid product, for example, LNG, methanol and other products, mainly of deep base, with the possibility of fixing it at a depth in the working position, for example, by means of a winch system, crossing a water mirror and / or ice cover, solid or broken, connected via pipelines with at least one XTC units for receiving a liquid product located on board an additional vessel, and at least one tank located on board the transport th vessel-product carriers.

 The liquid product storage is made in the form of a system of rigidly connected spherical tanks connected by means of pipelines of the liquid product. The liquid product storage is equipped with a heat exchanger made, for example, in the form of twisted and bent pipes connected to a refrigerant supply system.

 The complex includes at least one booster compressor station (DKS) of the steam generator of predominantly deep base with the possibility of fixing it at a depth in the working position, for example, by means of a winch system, its intersection with a water mirror and / or ice cover, solid or broken. An additional vessel of the complex is made in the form of at least one or more spherical shells located on one or more straight lines connected by a cylindrical shell.

 A marine offshore platform and / or offshore floating drilling rig and / or floating platform may be used as an offshore gas field structure.

 Figure 1-5 shows a structural diagram of a field development complex for natural gas deposits, including an offshore stationary platform (MSP) 1 for the production of natural gas (GHG), which is connected to the mouths of 2 wells through risers (flexible gas pipelines) 3.

 - FIG. 1. A design diagram of one of the options for an offshore gas field structure, an offshore stationary platform (MSP) with tension ties (tension supports and an additional suspended anchor system).

 - FIG. 2. Structural diagram of the marine stationary booster compressor station of the underwater gas station based on tension ties.

 - Figure 3. A structural diagram of one of the options for a marine stationary plant for the production of liquid products from underwater-based GHGs on tension ties.

 - Figure 4. Structural diagram of a marine stationary LNG storage with a heat exchanger for its undercooling underwater based on tension bonds.

 - FIG. 5. Surface transport product carrier ship of liquid products from GHGs.

 In case of danger of collision with an iceberg 4 or the need for a relocation of the platform, the upper floating part 5 of the platform is disconnected from the lower part 6 and retracted to a safe distance by tug 7.

 On platform 1 there is a chemical-technological system (CTS) of units for the preparation (field processing) of natural gas 8, including units for drying and purification.

GHG dehydration is carried out by means of absorbents (glycol dehydration of GHG, in which glycol absorbs water vapor from GHG during absorption). GHG purification from sulfur compounds and carbon dioxide is carried out in accordance with the requirements of the GHG consumer. The requirements for the content of sulfur components are constantly increasing: H ₂ S in GHG should be no more than 5.7 mg / m ³ , total sulfur - no more than 50 mg / m ³ .

 The deep cleaning of GHG from organosulfur compounds and hydrogen sulfide is carried out at the earliest possible stage of GHG treatment. The choice of purification method is determined by the composition of the gas in the field and the requirements for the degree of gas purification. HTS units of preparation (field processing) of GHG 8 consists of many functional structural units and is designed to implement the relationship between input and output streams, i.e. for carrying out the technological process of field processing of GHGs and neutralizing emissions (waste).

 By means of a gas pipeline 9, the gas treatment unit of the gas preparation units 8 is connected to a booster compressor station (DKS) 10, the need for which is determined by ensuring the constancy of the GHG parameters and a decrease in reservoir pressure during the operation of gas fields. The ability to enable DCS 10 can be carried out by valves 11, 12.

 Natural gas of predetermined parameters and composition is supplied through a gas pipeline 13 to a gas manifold-distributor 14 of an additional vessel 15, on board of which are located chemical-technological systems (CTS) of units for producing a liquid product 16 from NG (LNG, methanol). The optimal number of CTAs of the units for producing a liquid product 16 and their productivity are determined from considerations of reliability and uninterrupted production of a liquid product by redundant CTS, as well as the regulations for their start-up after shutdown.

 The CTS of the units for the production of liquid product 16 from GHG (LNG, methanol and other products) consists of many functional structural units and is designed to implement the relationship between the input and output flows of GHG and the final liquid product, i.e. for carrying out the technological process of obtaining a given liquid product of neutralizing emissions (waste) and interacting with the environment on serial CTS, imported and domestic production.

 The additional vessel 15 is equipped with a collector 17 for collecting the obtained liquid chemical product, locks 18, 19 mounted on the hull 20 of the vessel 15, made in the form of a spherical shell.

Due to the irregular movement of food carrier vessels 21, the complex has a storage facility 22 with a total capacity of ~ 400 thousand m ^{3 of} liquid product.

 The storage 22 is made in the form of a system of interconnected pipelines of spherical tanks 23 mounted on a rigid platform 24. The evaporated product through the nozzle 25 is disposed of, and the GHG is re-liquefied.

 DKS 10, additional vessel 15, storage 22 mounted on a rigid platform 24, are made with the possibility of underwater basing, crossing a water mirror and overcoming ice cover, solid or broken, and fixing these objects according to a given topology at a depth using winches 26.

 Liquid product is transferred from storage 22 through special-purpose pipelines 27, including cryotube pipelines, to product-carrying vessels 21. LNG is transported in methane carriers, which are part of the chartering services and are produced at the shipyards in series (A.O. Kverner. Masa- Yards, Turku).

 In 1995, the authors conducted research work in the interests of the Malachite Special-Purpose Marine Design Bureau - Vyborg Scientific Production Foundation on the feasibility of transporting liquid products by gas carrier vessels (seven products) and revealed the efficiency of their transportation in a supercooled state: average cargo cost savings of 15%.

 A heat exchange device 28, made, for example, in the form of a coil, through which a refrigerant (liquid nitrogen) circulates through a pipe space, is located inside the liquid product storage 22, and is connected by a cryo-drive 29 to a cryo-supply system 30.

 The cryosupply system 30, formed on the basis of cryogenic liquid nitrogen production facilities, is deployed at an autonomous floating plant for its production mainly underwater based on the agreed technological topology of the complex.

 The cryo-supply system of a complex for supercooling a liquid transported product by ships assumes the existence of high-power drive power machines (turbines) in its composition, constructed on the principle of using a pressure differential in the turbines generated by the pressure of the gas field layer and the pressure at the inlet to the GHG liquefaction unit.

 The complex essentially achieves a reduction in the volume of transported GHG by approximately 600 times by changing the aggregate state of dry GHG by liquefying it and by increasing the density of GHGs and other liquid products by 15 ... 20% by supercooling liquefied gases and the resulting liquid products to the optimum temperature.

 In addition, the profitability of developing offshore gas fields in the Arctic and its transport for export or the domestic market to the consumer can also be increased by processing it into methanol and other liquid products in the area where the fields are located.

The total effect (economic and technical) is achieved due to the following components (articles) of it, which are the result of the application of this concept for the development of gas fields and transport of products:
1. The economic effect of the delivery of additional refrigerated below the boiling point of LNG, LPG, other products of the transported mass product carrier for the flight.

 2. The economic effect of transporting products by fewer vessels under the articles of insurance of cargo and the vessel, its construction cost, article on collection of port charges, for the service provided to the vessel when the vessel enters the consumer's port, under the item of saving fuel costs during the implementation of the product transportation program, according to daily maintenance on the go and parking of the vessel, under the article of insurance of the personnel of the vessel, under the article of the cost of accumulated cold delivered to the consumer of the product.

The most significant and significant consequences arising from hypothermia and increasing the density of the CIS and LNG for their transportation and concentrated in the technical and economic effect of this technical solution include:
1. The use of external insulation of tanks, increasing the mechanical and fatigue strength of the tank structure several times due to direct contact of the CIS, LNG with the material of the tank, increasing the mechanical properties when cooled to cryogenic temperatures.

 2. Reducing the load on the system of re-liquefaction of the CIS, LNG vessel.

 3. Improving the reliability of the functioning of the pumping system by providing cavitation-free modes of pumps for overload with positive and negative suction heights.

 4. The increase in the range of pipeline transport (delivery) of the CIS, LNG and other products in the industrial zone of their consumer or to the storage.

 5. The possibility of creating industries utilizing the cold of the CIS, LNG and other products.

 In some versions of installations for the production of a liquid product from natural gas, such as LNG, methanol, it is advisable to place the largest XTC chemical-technological units for producing a liquid product from GHG from the outside of the hulls of such objects as an additional vessel, storage facilities, and booster booster.

 Such functional-structural units with elementary processes occurring in them (thermal, mass transfer, etc.) are a methanol synthesis column with a condenser, a cryogenic GHG liquefaction heat exchanger, and an GHG cooling heat exchanger with outboard water.

 In this case, intensification of heat transfer in XTC and reduction of the heat transfer surface in devices are achieved.

Claims (6)

 1. A complex for commercial development of natural gas fields, including an offshore platform or a floating platform and the chemical-technological system of units for preparing natural gas, the chemical-technological system of units for producing a liquid product, the gas-supply system for supplying natural gas to the chemical-technological system for units for receiving them liquid product from a chemical-technological system of natural gas preparation units and at least one transport product carrier vessel for export liquid product to the consumer, for example, in spherical tanks located on its board, characterized in that at least one additional vessel is introduced into the complex, mainly of deep base, with the possibility of fixing it at a depth in the working position, for example, by means of a winch system, crossing it mirrors of water and / or ice cover, predominantly tiny, on board of which at least one chemical-technological system of units for producing a liquid product, for example, liquefied natural gas, methanol and other products, which is connected to a chemical-technological system for the preparation of natural gas through a flexible system of pipelines for supplying natural gas, made, for example, in the form of a system of interconnected spherical sealed joints, and through a system of flexible pipelines of a liquid product with tanks, for example, spherical in shape, located on board at least one transport product vessel surface or underwater.  2. The complex according to p. 1, characterized in that the storage of a liquid product, for example, liquefied natural gas, methanol and other products, mainly deep-based, with the possibility of fixing it at a depth in the working position, for example, through a winch system, crossing them mirrors of water and / or ice cover, predominantly tiny, and connection via pipelines to at least one chemical-technological system of units for producing a liquid product, located on board an additional vessel And at least one tank located on board the vehicle includes product vessel.  3. The complex according to claim 1 or 2, characterized in that the storage is made in the form of a system of rigidly connected spherical tanks connected by means of pipelines of a liquid product.  4. The complex according to claim 1 or 2, characterized in that the storage is equipped with a heat exchange device, made, for example, in the form of twisted or bent pipes connected to a refrigerant supply system.  5. The complex according to claim 1, characterized in that at least one compressing natural gas compressor station, mainly of deep base, is introduced into it with the possibility of fixing it at a depth in the working position, for example, by means of a winch system, by crossing a water mirror and / or ice cover, predominantly tiny.  6. The complex according to claim 1, characterized in that the additional vessel is made in the form of at least one or more spherical shells located on one or more straight lines interconnected by cylindrical shells.

Images