EP3156665A1 - Compressor system, subsea production system provided therewith, and compressor cleaning method - Google Patents
Compressor system, subsea production system provided therewith, and compressor cleaning method Download PDFInfo
- Publication number
- EP3156665A1 EP3156665A1 EP15821658.0A EP15821658A EP3156665A1 EP 3156665 A1 EP3156665 A1 EP 3156665A1 EP 15821658 A EP15821658 A EP 15821658A EP 3156665 A1 EP3156665 A1 EP 3156665A1
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- Prior art keywords
- compressor
- supply
- freezing agent
- anti freezing
- hydrate anti
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- 238000004140 cleaning Methods 0.000 title claims description 86
- 238000000034 method Methods 0.000 title claims description 76
- 238000004519 manufacturing process Methods 0.000 title claims description 53
- 230000008014 freezing Effects 0.000 claims abstract description 218
- 238000007710 freezing Methods 0.000 claims abstract description 218
- 230000036571 hydration Effects 0.000 claims abstract description 13
- 238000006703 hydration reaction Methods 0.000 claims abstract description 13
- 239000012530 fluid Substances 0.000 claims description 26
- 239000007788 liquid Substances 0.000 claims description 26
- 238000010438 heat treatment Methods 0.000 claims description 22
- 239000003795 chemical substances by application Substances 0.000 description 193
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 130
- 239000007789 gas Substances 0.000 description 85
- 239000003345 natural gas Substances 0.000 description 70
- 239000010779 crude oil Substances 0.000 description 25
- 239000013049 sediment Substances 0.000 description 16
- 239000003921 oil Substances 0.000 description 15
- 238000005507 spraying Methods 0.000 description 12
- 230000006835 compression Effects 0.000 description 7
- 238000007906 compression Methods 0.000 description 7
- 238000011109 contamination Methods 0.000 description 5
- 238000011144 upstream manufacturing Methods 0.000 description 5
- 238000003860 storage Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000007792 addition Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000001033 ether group Chemical group 0.000 description 1
- 238000003306 harvesting Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/70—Suction grids; Strainers; Dust separation; Cleaning
- F04D29/701—Suction grids; Strainers; Dust separation; Cleaning especially adapted for elastic fluid pumps
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B37/00—Methods or apparatus for cleaning boreholes or wells
- E21B37/06—Methods or apparatus for cleaning boreholes or wells using chemical means for preventing, limiting or eliminating the deposition of paraffins or like substances
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/01—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells specially adapted for obtaining from underwater installations
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/34—Arrangements for separating materials produced by the well
- E21B43/36—Underwater separating arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
- F04D17/08—Centrifugal pumps
- F04D17/10—Centrifugal pumps for compressing or evacuating
- F04D17/12—Multi-stage pumps
- F04D17/122—Multi-stage pumps the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
- F04D25/0686—Units comprising pumps and their driving means the pump being electrically driven specially adapted for submerged use
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
- F04D27/001—Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/70—Suction grids; Strainers; Dust separation; Cleaning
- F04D29/701—Suction grids; Strainers; Dust separation; Cleaning especially adapted for elastic fluid pumps
- F04D29/705—Adding liquids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
- F04D17/08—Centrifugal pumps
- F04D17/10—Centrifugal pumps for compressing or evacuating
- F04D17/12—Multi-stage pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/403—Casings; Connections of working fluid especially adapted for elastic fluid pumps
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Control Of Positive-Displacement Air Blowers (AREA)
Abstract
Description
- The present invention relates to a compressor system, a subsea production system provided therewith, and a compressor cleaning method.
- In subsea production systems configured to extract submarine resources, production fluids mixed with crude oils and natural gases are drawn from production wells drilled to a depth of several thousand meters in the seabed. In the subsea production systems, the drawn production fluids are separated into gases such as natural gases and liquids such as crude oils by a separator such as a scrubber and are then sent to a ship on the sea surface through flow lines that extend under the sea. In this case, in order to send gases such as natural gases to a ship on the sea surface, a compressor installed in the seabed is used.
- In the compressor installed in the seabed in this manner, according to continuous operations, sediments accumulate in internal flow paths through which natural gases circulate. As a result, a flow rate of natural gases that can circulate in the internal flow paths decreases and efficiency of the compressor decreases.
- For such a compressor, for example, a cleaning method in which some condensates that are hydrocarbons contained in liquids separated out in the separator are supplied to the compressor for cleaning is disclosed in
Patent Literature 1. In the compressor cleaning method, the condensates decompose and remove sediments, and internal flow paths of the compressor are cleaned. - [Patent Literature 1] PCT International Publication No.
WO 2013/185801 - However, in the above-described cleaning method, condensates harvested from production wells are used. Therefore, in the cleaning method, there is a risk of a necessary amount of condensates not being reliably harvested from production wells. As a result, it is difficult to reliably clean the compressor.
- The present invention provides a compressor system capable of reliably cleaning a compressor, a subsea production system provided therewith, and a compressor cleaning method.
- In order to address the above problems, the present invention proposes the following solutions. A compressor system according to a first aspect of the present invention includes a compressor including a casing, a rotation shaft supported in the casing, and an impeller that rotates together with the rotation shaft and compresses a gas; a compressed gas circulation unit in which the gas compressed by the compressor circulates; a hydrate anti freezing agent supply unit configured to supply a hydrate anti freezing agent that prevents hydration of the gas to the compressed gas circulation unit; and an internal hydrate anti freezing agent supply unit configured to supply part of the hydrate anti freezing agent supplied from the hydrate anti freezing agent supply unit to an internal flow path formed of the impeller and the casing.
- In such a configuration, part of the hydrate anti freezing agent supplied from the hydrate anti freezing agent supply unit to the compressed gas circulation unit for preventing hydration of the gas compressed by the compressor is supplied to the internal flow path. Therefore, the hydrate anti freezing agent flows in the internal flow path together with the gas, and thus sediments accumulated in the internal flow path can be removed. When the hydrate anti freezing agent is directly supplied to the internal flow path, the hydrate anti freezing agent is prevented from being diluted by the gas before reaching the internal flow path, and it is possible to clean the inside of the compressor by effectively using the hydrate anti freezing agent. When part of the hydrate anti freezing agent supplied from the hydrate anti freezing agent supply unit to the compressed gas circulation unit is used, it is possible to reliably supply a necessary amount of the hydrate anti freezing agent to the internal flow path.
- The compressor system may include a control unit configured to perform supply control such that, when predetermined conditions are satisfied, the internal hydrate anti freezing agent supply unit starts supply of the hydrate anti freezing agent to the internal flow path.
- In such a configuration, when supply control of the hydrate anti freezing agent is performed by the control unit, it is possible to limit supply of the hydrate anti freezing agent to the compressor that is in a state in which cleaning is necessary. Therefore, the hydrate anti freezing agent supplied from the internal hydrate anti freezing agent supply unit can be efficiently used for cleaning the compressor and it is possible to minimize a supply amount of the hydrate anti freezing agent.
- In the compressor system, the control unit may include a first reference determination unit configured to determine whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference and a supply start instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to start supply of the hydrate anti freezing agent to the internal flow path when the first reference determination unit determines that the first reference is satisfied.
- In such a configuration, when a difference between characteristic values of the gas on the inlet side and the outlet side of the compressor is calculated, the calculated difference is compared with a predetermined first reference and determination is performed in the first reference determination unit, it is possible to easily determine whether the internal flow path is in a state in which cleaning is necessary. When the supply start instruction unit starts supply of the hydrate anti freezing agent to the internal flow path based on the determination result, it is possible to perform cleaning of the internal flow path. Therefore, it is possible to determine whether the compressor is in a state in which cleaning is necessary with high accuracy and it is possible to further limit supply of the hydrate anti freezing agent. Therefore, for the internal flow path for which cleaning is necessary, the hydrate anti freezing agent supplied from the internal hydrate anti freezing agent supply unit can be used for cleaning the compressor more efficiently and a supply amount of the hydrate anti freezing agent can be further minimized.
- The compressor system may include a heating unit configured to heat the hydrate anti freezing agent, and the internal hydrate anti freezing agent supply unit may supply the hydrate anti freezing agent heated by the heating unit to the internal flow path.
- In such a configuration, when the heating unit is provided, a high temperature hydrate anti freezing agent can be supplied to the internal flow path. It is thus possible to improve solubility of sediments due to the hydrate anti freezing agent that is heated to a high temperature. Therefore, it is possible to increase a dissolution rate of sediments accumulated in the internal flow path and effectively clean the internal flow path.
- The compressor system may include a heating unit configured to heat the hydrate anti freezing agent, and the control unit may include a second reference determination unit configured to determine whether a difference between characteristic values of the gas on the inlet side of the compressor and the outlet side of the compressor satisfies a predetermined second reference after supply of the hydrate anti freezing agent to the internal flow path starts; and a heat supply instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to supply the hydrate anti freezing agent heated by the heating unit to the internal flow path when the second reference determination unit determines that the second reference is satisfied.
- In such a configuration, when a difference between characteristic values of the gas on the inlet side and the outlet side of the compressor is calculated, the calculated difference is compared with a second reference and determination is performed in the second reference determination unit, it is possible to easily determine again whether the internal flow path is in a state in which cleaning is necessary. Therefore, for example, it is possible to easily determine a state of the internal flow path that is different from the state determined using the first reference. Based on the determination result, when the heat supply instruction unit sends an instruction to supply the hydrate anti freezing agent heated by the heating unit to the internal flow path, it is possible to perform cleaning of the internal flow path more effectively using the hydrate anti freezing agent that is heated to a high temperature. Therefore, it is possible to perform greater cleaning on the compressor as necessary. Therefore, when the internal flow path is in a state in which greater cleaning is necessary, it is possible to efficiently supply the heated hydrate anti freezing agent and clean the compressor more efficiently.
- According to a second aspect of the present invention, there is provided a subsea production system that includes the compressor system and a separator configured to separate a production fluid drawn from a production well into a gas and a liquid and supply the result to the compressor.
- In such a configuration, it is also possible to reliably and efficiently clean the compressor that is installed at a position at which maintenance is difficult, for example, in the seabed. Therefore, it is possible to prevent clogging due to sediments and it is possible to reliably send the gas through the compressor.
- According to a third aspect according to the present invention, there is provided a compressor cleaning method in which a compressor including a casing, a rotation shaft supported in the casing and an impeller that rotates together with the rotation shaft and compresses a gas is cleaned, the method including: a first reference determining process of determining whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference; and a supply start process in which, when it is determined that the first reference is satisfied in the first reference determining process, supply of a hydrate anti freezing agent that prevents hydration of the gas compressed by the compressor to an internal flow path formed of the impeller and the casing starts.
- In such a configuration, when a difference between characteristic values of the gas on the inlet side and the outlet side of the compressor is calculated, the calculated difference is compared with a first reference and determination is performed in the first reference determining process, it is possible to easily determine whether the internal flow path is in a state in which cleaning is necessary. When supply of the hydrate anti freezing agent to the internal flow path starts in the supply start process based on the determination result, it is possible to perform cleaning of the internal flow path. Therefore, it is possible to determine whether the compressor is in a state in which cleaning is necessary with high accuracy and it is possible to further limit supply of the hydrate anti freezing agent. Therefore, for the internal flow path for which cleaning is necessary, the hydrate anti freezing agent supplied from the internal hydrate anti freezing agent supply unit can be used for cleaning the compressor more efficiently and a supply amount of the hydrate anti freezing agent can be further minimized.
- The compressor cleaning method may include a second reference determining process in which, after supply of the hydrate anti freezing agent to the internal flow path starts, it is determined whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined second reference; and a heat supply process in which, when it is determined that the second reference is satisfied in the second reference determining process, the heated hydrate anti freezing agent is supplied to the internal flow path.
- In such a configuration, when a difference between characteristic values of the gas on the inlet side and the outlet side of the compressor is calculated, the calculated difference is compared with the second reference and determination is performed in the second reference determining process, it is possible to easily determine again whether the internal flow path is in a state in which cleaning is necessary. For example, it is possible to easily determine whether the internal flow path is in a state different from the state determined using the first reference (for example, whether greater cleaning is necessary for the internal flow path). Based on the determination result temperature, in the heat supply process, when the hydrate anti freezing agent heated to a high temperature is supplied from a hydrate anti freezing agent spraying unit to the internal flow path, it is possible to perform cleaning of the internal flow path more effectively. Therefore, it is possible to perform greater cleaning on the compressor as necessary. Therefore, when the internal flow path is in a state in which greater cleaning is necessary, it is possible to efficiently supply the heated hydrate anti freezing agent and clean the compressor more efficiently.
- According to the present invention, it is possible to efficiently clean the compressor by supplying the hydrate anti freezing agent to the internal flow path.
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Fig. 1 is a diagram schematically showing a subsea production system in an embodiment of the present invention. -
Fig. 2 is a systematic diagram showing a subsea module in an embodiment of the present invention. -
Fig. 3 is a cross-sectional view of a main part showing an internal flow path of a compressor in an embodiment of the present invention. -
Fig. 4 is a flowchart describing a compressor cleaning method in an embodiment of the present invention. - Hereinafter, embodiments according to the present invention will be described with reference to
Fig. 1 to Fig. 4 . Asubsea production system 1 according to an embodiment of the present invention is a subsea production system that is one for ocean oil and gas field development methods. As shown inFig. 1 , thesubsea production system 1 includes a production well W for harvesting a production fluid PF mixed with crude oil O, natural gas G and the like extracted from an oil gas field F that is located several hundreds to thousands of meters from the seabed, a manifold M for collecting and distributing the production fluid PF harvested in the production well W, a flow line FL that is a pipe through which the production fluid PF distribute by the manifold M is conveyed, and a subsea module SM configured to separate the production fluid PF conveyed through the flow line FL into a liquid and a gas and send them to the sea surface. Thesubsea production system 1 includes a riser R that is a pipe through which the crude oil O and the natural gas G are conveyed to the sea surface from the subsea module SM, an umbilical line AL that is a cable through which power is supplied to the subsea module SM and the like, and a ship S to which the riser R and the umbilical line AL moored in the sea are connected and in which the crude oil O and the natural gas G are stored. - The manifold M is installed in the vicinity of the production well W of the oil gas field F in the seabed. The manifold M is a device configured to collect and distribute the extracted production fluid PF and convey it through a plurality of flow lines FL.
- The flow line FL is a pipeline through which the production fluid PF is pressure-fed from the manifold M to the subsea module SM according to pressure energy of the oil gas field F.
- The riser R extends from the subsea module SM of the seabed to the ship S on the sea surface. In the riser R of this embodiment, an oil pipeline OR through which the crude oil O sent from the subsea module SM is conveyed to a storage tank (not shown) disposed in the ship S on the sea surface and a gas pipeline GR through which the natural gas G sent from the subsea module SM is conveyed to the storage tank are separately provided. The riser R includes the gas pipeline GR through which the natural gas G is supplied such that the natural gas G is prevented from freezing due to hydration in the seabed and a pipeline for a hydrate anti freezing agent AR through which a hydrate anti freezing agent is supplied from the ship S.
- The umbilical line AL is a composite cable including a power cable, a hydraulic cable and a signal cable for controlling the subsea module SM. The umbilical line AL sends power and signals from a generator (not shown) in the ship S to the subsea module SM and the manifold M.
- The subsea module SM separates the production fluid PF supplied through the flow line FL into a gas and a liquid and pressure-feeds the gas and the liquid to the sea surface. As shown in
Fig. 2 , the subsea module SM of this embodiment includes amain heat exchanger 2 configured to cool the production fluid PF drawn from the production well W, aseparator 3 configured to separate the production fluid PF cooled in themain heat exchanger 2 into a gas and a liquid, apump system 4 configured to send the liquid separated out in theseparator 3 to the riser R, and acompressor system 5 configured to send the gas separated out by theseparator 3 to the riser R. - The
main heat exchanger 2 cools the production fluid PF having a high temperature that is drawn from the production well W and sent to the flow line FL to a temperature at which the production fluid PF can be used in theseparator 3. Themain heat exchanger 2 of this embodiment cools the production fluid PF according to heat exchange with low temperature seawater of the seabed. - The
separator 3 separates the production fluid PF into the natural gas G that is a gas and the crude oil O that is a liquid. Theseparator 3 of this embodiment is a scrubber. Theseparator 3 separates the natural gas G and the crude oil O containing condensates from the production fluid PF. Theseparator 3 sends the separated crude oil O to thepump system 4. Theseparator 3 sends the separated natural gas G to thecompressor system 5. - The
pump system 4 compresses the crude oil O sent from theseparator 3 and sends it to the oil pipeline OR. As shown inFig. 2 , thepump system 4 includes apump 41 configured to compress the crude oil O, aliquid circulation unit 42 configured to send the crude oil O from theseparator 3 to thepump 41, and a compressedliquid circulation unit 43 in which the crude oil O compressed by thepump 41 circulates. - The
pump 41 compresses and sends out the received crude oil O. Theliquid circulation unit 42 supplies the crude oil O from theseparator 3 to thepump 41. Specifically, theliquid circulation unit 42 of this embodiment is a pipe that is connected from theseparator 3 to thepump 41. The crude oil O circulates inside theliquid circulation unit 42. The compressedliquid circulation unit 43 sends the crude oil O compressed by thepump 41 to the oil pipeline OR. Specifically, the compressedliquid circulation unit 43 of this embodiment is a pipe that is connected from thepump 41 to the oil pipeline OR. The compressed crude oil O circulates inside the compressedliquid circulation unit 43. - The
compressor system 5 compresses the natural gas G sent from theseparator 3 and sends it to the gas pipeline GR. As shown inFig. 2 , thecompressor system 5 includes acompressor 50 configured to compress the natural gas G, agas circulation unit 51 configured to send the natural gas G from theseparator 3 to thecompressor 50, a compressedgas circulation unit 52 in which the natural gas G that is compressed by thecompressor 50 circulates, a hydrate anti freezingagent supply unit 53 configured to supply a hydrate anti freezing agent for preventing hydration of the natural gas G to the compressedgas circulation unit 52, an internal hydrate anti freezingagent supply unit 54 configured to supply part of the hydrate anti freezing agent supplied from the hydrate anti freezingagent supply unit 53 to thecompressor 50, aheating unit 55 configured to heat the hydrate anti freezing agent, and acontrol unit 60 configured to perform supply control such that the internal hydrate anti freezingagent supply unit 54 starts supply of the hydrate anti freezing agent. - The
compressor 50 is a multistage centrifugal compressor including a plurality ofimpellers 503. As shown inFig. 3 , thecompressor 50 of this embodiment includes acasing 501 on which an internal flow path FC through which a gas flows from an upstream side to a downstream side is formed, arotation shaft 502 that is supported in thecasing 501 and rotates around an axis SL, and theimpellers 503 that rotate together with therotation shaft 502 and compress a gas. - The
casing 501 is a stationary body and has a tubular shape. In thecasing 501, therotation shaft 502 is disposed to penetrate the center. A bearing device (not shown) is provided in thecasing 501. The bearing device rotatably supports therotation shaft 502. - The
rotation shaft 502 is a rotating body, has a columnar shape and extends in an axis SL direction in which the shaft line SL extends. Theimpeller 503 is a rotating body. The plurality ofimpellers 503 are provided at intervals in the shaft line SL direction of therotation shaft 502. Theimpellers 503 compress the natural gas G (gas) using a centrifugal force according to rotation. Theimpeller 503 includes adisk 503a, ablade 503b, and acover 503c. Theimpeller 503 is a so-calledclosed type impeller 503. - The
disk 503a is formed in a disk shape whose diameter gradually increases outward in a radial direction of therotation shaft 502 toward a downstream side that is one side in the shaft line SL direction in therotation shaft 502. Theblade 503b is formed to protrude toward an upstream side in the shaft line SL direction which is a side opposite to a downstream side in the shaft line SL direction from thedisk 503a. The plurality ofblades 503b are formed in thedisk 503a at predetermined intervals in a circumferential direction of the shaft line SL. Thecover 503c covers the plurality ofblades 503b from an upstream side in the shaft line SL direction. Thecover 503c is formed in a disk shape that faces thedisk 503a. - The internal flow path FC is formed by the
impeller 503 and thecasing 501 so as to connect theimpellers 503 so that the natural gas G is gradually compressed. The internal flow path FC includes a compression flow path FC1 defined by theimpeller 503 and a casing flow path FC2 that is formed inside thecasing 501 and in which a flow of the natural gas G is adjusted. - The compression flow path FC1 is defined by a surface that faces an upstream side in the shaft line SL direction of the
disk 503a, a surface that faces a downstream side in the shaft line SL direction of thecover 503c, and a surface that faces in a circumferential direction of theblade 503b. The casing flow path FC2 adjusts a flow of the natural gas G to flow the natural gas G through the compression flow path FC1 defined by theimpeller 503. - The
gas circulation unit 51 supplies the natural gas G from theseparator 3 to thecompressor 50. Specifically, thegas circulation unit 51 of this embodiment is a pipe that is connected from theseparator 3 to thecompressor 50 as shown inFig. 2 . The natural gas G circulates inside thegas circulation unit 51. Thegas circulation unit 51 of this embodiment includes an inlet side characteristicvalue measuring unit 511 configured to measure a characteristic value of the natural gas G on an inlet side of thecompressor 50. - The inlet side characteristic
value measuring unit 511 measures a characteristic value of the natural gas G that flows into thecompressor 50. The inlet side characteristicvalue measuring unit 511 is provided in the vicinity of an inlet port of thecompressor 50 of thegas circulation unit 51. The inlet side characteristicvalue measuring unit 511 of this embodiment is a pressure sensor that measures a pressure value as a characteristic value. The inlet side characteristicvalue measuring unit 511 transmits the measured pressure value of the natural gas G to thecontrol unit 60. - The compressed
gas circulation unit 52 sends the natural gas G compressed by thecompressor 50 to the riser R. Specifically, the compressedgas circulation unit 52 of this embodiment is a pipe that is connected from thecompressor 50 to the gas pipeline GR. The compressed natural gas G circulates inside the compressedgas circulation unit 52. The compressedgas circulation unit 52 of this embodiment includes an outlet side characteristicvalue measuring unit 521 configured to measure a characteristic value of the natural gas G (gas) on an outlet side of thecompressor 50. - The outlet side characteristic
value measuring unit 521 measures a characteristic value of the natural gas G discharged from thecompressor 50. The outlet side characteristicvalue measuring unit 521 is provided in the vicinity of an outlet port of thecompressor 50 of the compressedgas circulation unit 52. Similarly to the inlet side characteristicvalue measuring unit 511, the outlet side characteristicvalue measuring unit 521 of this embodiment is a pressure sensor that measures a pressure value as a characteristic value. The outlet side characteristicvalue measuring unit 521 transmits the measured pressure value of the natural gas G to thecontrol unit 60. - The hydrate anti freezing
agent supply unit 53 circulates the hydrate anti freezing agent supplied from the ship S on the sea surface through the pipeline for a hydrate anti freezing agent AR to the compressedgas circulation unit 52. The hydrate anti freezingagent supply unit 53 of this embodiment is a pipe that is connected from the pipeline for a hydrate anti freezing agent AR to the compressedgas circulation unit 52. The hydrate anti freezing agent circulates inside the hydrate anti freezingagent supply unit 53. The hydrate anti freezingagent supply unit 53 is connected downstream from a position at which the outlet side characteristicvalue measuring unit 521 of the compressedgas circulation unit 52 is provided. Also, as the hydrate anti freezing agent of this embodiment, a fluid having lipophilicity and hydrophilicity is preferably used. As the hydrate anti freezing agent, for example, monoethylene glycol used for preventing hydration by preventing hydration of the natural gas G is particularly preferably used. - The internal hydrate anti freezing
agent supply unit 54 supplies part of the hydrate anti freezing agent that flows in the hydrate anti freezingagent supply unit 53 to the internal flow path FC of thecompressor 50. Specifically, the internal hydrate anti freezingagent supply unit 54 of this embodiment includes afirst supply pipe 541, afirst supply valve 542 configured to adjust a flow of a hydrate anti freezing agent that flows in thefirst supply pipe 541, asecond supply pipe 543 that branches from thefirst supply pipe 541, and a second supply valve 544 configured to adjust a flow of a hydrate anti freezing agent that flows in thesecond supply pipe 543. - The
first supply pipe 541 branches from the hydrate anti freezingagent supply unit 53 and is connected to thecasing 501 of thecompressor 50. Specifically, thefirst supply pipe 541 of this embodiment is connected to pass through the inside of thecasing 501 of thecompressor 50. Thefirst supply pipe 541 branches at the inside of thecasing 501. At a distal portion of thefirst supply pipe 541, a hydrate anti freezingagent spraying unit 541 a configured to spray a hydrate anti freezing agent toward the casing flow path FC2 is provided. - The
first supply valve 542 adjusts supply of a hydrate anti freezing agent into thefirst supply pipe 541. Specifically, when thefirst supply valve 542 of this embodiment is closed, supply of a hydrate anti freezing agent into thefirst supply pipe 541 stops and when thefirst supply valve 542 of this embodiment is opened, supply of a hydrate anti freezing agent into thefirst supply pipe 541 starts. Thefirst supply valve 542 is a solenoid valve in which opening and closing operations are controlled by thecontrol unit 60. - The
second supply pipe 543 branches from thefirst supply pipe 541 and supplies a hydrate anti freezing agent to thecompressor 50. Thesecond supply pipe 543 of this embodiment branches from thefirst supply pipe 541 on an upstream side relative to a position at which thefirst supply valve 542 is provided and is connected to thefirst supply pipe 541 again at a downstream side relative to a position at which thefirst supply valve 542 is provided. - The second supply valve 544 adjusts supply of a hydrate anti freezing agent into the
second supply pipe 543. Specifically, when the second supply valve 544 of this embodiment is closed, supply of a hydrate anti freezing agent into thesecond supply pipe 543 stops and when the second supply valve 544 of this embodiment is opened, supply of a hydrate anti freezing agent into thesecond supply pipe 543 starts. The second supply valve 544 is a solenoid valve whose opening and closing operations are controlled by thecontrol unit 60. - The
heating unit 55 is provided in the internal hydrate anti freezingagent supply unit 54 and heats a hydrate anti freezing agent. Theheating unit 55 of this embodiment is provided at a position that is on a downstream side relative to the second supply valve 544 of thesecond supply pipe 543 and at which thesecond supply pipe 543 and theliquid circulation unit 42 cross. Theheating unit 55 heats a hydrate anti freezing agent by using heat of the crude oil O that flows in thepump system 4. Specifically, theheating unit 55 heats monoethylene glycol which is a hydrate anti freezing agent that flows in thesecond supply pipe 543 at an ambient temperature of, for example, about 20 °C to 50 °C, to a high temperature of 110 °C or more. - When predetermined conditions are satisfied, the
control unit 60 performs supply control such that the internal hydrate anti freezingagent supply unit 54 starts supply of a hydrate anti freezing agent into the internal flow path FC of thecompressor 50. When predetermined conditions are satisfied, thecontrol unit 60 of this embodiment controls opening and closing operations of thefirst supply valve 542 and the second supply valve 544, and thus supply of a hydrate anti freezing agent into the internal flow path FC is controlled. - Specifically, the
control unit 60 of this embodiment includes afirst input unit 61 configured to receive a characteristic value measured by the inlet side characteristicvalue measuring unit 511, asecond input unit 62 configured to receive a characteristic value measured by the outlet side characteristicvalue measuring unit 521, and adifference calculation unit 63 configured to calculate a difference between the characteristic value received by thefirst input unit 61 and the characteristic value received by thesecond input unit 62. Thecontrol unit 60 of this embodiment includes a first reference determination unit 64 configured to determine whether the difference calculated by thedifference calculation unit 63 satisfies a predetermined first reference and a supplystart instruction unit 65 configured to send an instruction to start supply of a hydrate anti freezing agent to the internal flow path FC based on the determination result of the first reference determination unit 64. Thecontrol unit 60 of this embodiment includes a secondreference determination unit 66 configured to determine whether the difference calculated by thedifference calculation unit 63 satisfies a predetermined second reference, a heatsupply instruction unit 67 configured to send an instruction to supply the hydrate anti freezing agent heated by theheating unit 55 to the internal flow path FC based on the determination result of the secondreference determination unit 66, and a cleaningtermination instruction unit 70 configured to send an instruction to terminate supply of the hydrate anti freezing agent to the internal flow path FC based on the determination result of the secondreference determination unit 66. Thecontrol unit 60 of this embodiment includes a first supplyvalve instruction unit 68 configured to open or close thefirst supply valve 542 based on an input signal and a second supplyvalve instruction unit 69 configured to open or close the second supply valve 544 based on an input signal. - The
first input unit 61 receives a pressure value of the natural gas G measured by the inlet side characteristicvalue measuring unit 511. Thefirst input unit 61 outputs information about the input pressure value to thedifference calculation unit 63. Thesecond input unit 62 receives a pressure value of the natural gas G measured by the outlet side characteristicvalue measuring unit 521. Thesecond input unit 62 outputs information about the input pressure value to thedifference calculation unit 63. - The
difference calculation unit 63 calculates a difference by subtracting a pressure value on an inlet side of a compressor input by thefirst input unit 61 from a pressure value on an outlet side of a compressor input by thesecond input unit 62. Thedifference calculation unit 63 outputs the calculated difference to the first reference determination unit 64. After the calculated difference is output to the first reference determination unit 64, when information is input again from thefirst input unit 61 and thesecond input unit 62, thedifference calculation unit 63 outputs the calculated difference to the secondreference determination unit 66. - The first reference determination unit 64 compares information about the difference input from the
difference calculation unit 63 with a first reference. Here, the first reference is a value indicating a state in which cleaning is necessary since sediments have precipitated and the internal flow path FC of thecompressor 50 is narrowed. The first reference of this embodiment is set to a value smaller than a value of a rise a pressure of the natural gas G that is compressed while circulating in the compression flow path FC1 in a normal state in which cleaning is not necessary. That is, the first reference of this embodiment is a value of a difference between pressures on an inlet side and an outlet side of thecompressor 50 while the internal flow path FC is narrowed due to sediments and the natural gas G is hardly compressed. - The first reference determination unit 64 of this embodiment determines whether the input difference value is less than the first reference. When it is determined that the calculated difference is less than the first reference and satisfies the first reference, the first reference determination unit 64 sends a signal to the supply
start instruction unit 65. - When the first reference determination unit 64 determines that the first reference is satisfied, the supply
start instruction unit 65 sends an instruction to the internal hydrate anti freezingagent supply unit 54 to start supply of a hydrate anti freezing agent to the internal flow path FC. When the signal is input from the first reference determination unit 64, the supplystart instruction unit 65 of this embodiment sends a signal to the first supplyvalve instruction unit 68 and sends an instruction to thefirst supply valve 542. - The second
reference determination unit 66 compares information about the difference input from thedifference calculation unit 63 with the second reference. Here, the second reference is a value indicating a state in which sediments of the internal flow path FC of thecompressor 50 are not sufficiently removed and greater cleaning is necessary. The second reference of this embodiment is set to a value smaller than a value of a rise of a pressure of the natural gas G that is compressed while circulating in the compression flow path FC1 in a normal state and is greater than the first reference. That is, the second reference of this embodiment is a value of a difference between pressures on the inlet side and the outlet side of thecompressor 50 in a state in which cleaning has been performed once, but the result is that this is not enough to satisfy the first reference, sediments remain in the internal flow path FC, and the natural gas G is not sufficiently compressed. - The second
reference determination unit 66 of this embodiment determines whether the input difference value is less than the second reference. When it is determined that the calculated difference is less than the second reference and satisfies the second reference, the secondreference determination unit 66 sends a signal to the heatsupply instruction unit 67. When it is determined that the calculated difference is greater than the second reference and does not satisfy the second reference, the secondreference determination unit 66 sends a signal to the cleaningtermination instruction unit 70. - When the second
reference determination unit 66 determines that the second reference is satisfied, the heatsupply instruction unit 67 sends an instruction to the internal hydrate anti freezingagent supply unit 54 to supply the hydrate anti freezing agent heated by theheating unit 55 to the internal flow path FC. The heatsupply instruction unit 67 of this embodiment receives the signal from the secondreference determination unit 66. As a result, the heatsupply instruction unit 67 sends a signal to the first supplyvalve instruction unit 68 and the second supplyvalve instruction unit 69 after the signal is sent from the supplystart instruction unit 65, and sends an instruction to thefirst supply valve 542 and the second supply valve 544. - When the second
reference determination unit 66 determines that the second reference is not satisfied, the cleaningtermination instruction unit 70 sends an instruction to the internal hydrate anti freezingagent supply unit 54 to terminate supply of a hydrate anti freezing agent to the internal flow path FC. The cleaningtermination instruction unit 70 of this embodiment receives a signal from the secondreference determination unit 66. As a result, the cleaningtermination instruction unit 70 sends a signal to the first supplyvalve instruction unit 68 and the second supplyvalve instruction unit 69 and sends an instruction to thefirst supply valve 542 and the second supply valve 544. - When the signal is input from the supply
start instruction unit 65, the first supplyvalve instruction unit 68 sends an instruction to open thefirst supply valve 542. When a signal is input from the heatsupply instruction unit 67, the first supplyvalve instruction unit 68 sends an instruction to close thefirst supply valve 542. When a signal is input from the cleaningtermination instruction unit 70, the first supplyvalve instruction unit 68 sends an instruction to close thefirst supply valve 542. - When a signal is input from the heat
supply instruction unit 67, the second supplyvalve instruction unit 69 sends an instruction to open the second supply valve 544. When a signal is input from the cleaningtermination instruction unit 70, the second supplyvalve instruction unit 69 sends an instruction to close the second supply valve 544. - Next, operations of the
subsea production system 1 of the above-described embodiment will be described. Thesubsea production system 1 of this embodiment collects the production fluid PF that is harvested from the oil gas field F through the production well W in the manifold M, conveys the collected production fluid PF into the flow line FL according to pressure energy generated when the production fluid PF is extracted from the oil gas field F, and supplies the production fluid PF to the subsea module SM. - In the subsea module SM, power is supplied to devices from a generator (not shown) in the ship S by the umbilical line AL. The production fluid PF supplied to the subsea module SM is cooled by the
main heat exchanger 2 and flows into theseparator 3. The production fluid PF flowed into theseparator 3 is separated into the crude oil O that is a liquid and the natural gas G that is a gas. Note that the crude oil O separated out in theseparator 3 includes condensates and the like. - The crude oil O separated out in the
separator 3 circulates inside theliquid circulation unit 42 and is sent to thepump 41. Thepump 41 compresses the crude oil O, sends it to the oil pipeline OR through the compressedliquid circulation unit 43 and supplies it to a crude oil O storage tank (not shown) in the ship S. - The natural gas G separated out by the
separator 3 circulates inside theliquid circulation unit 42 and is sent to thecompressor 50. In thecompressor 50, when the natural gas G circulates in the internal flow path FC, theimpeller 503 rotates together with therotation shaft 502 so that the natural gas G is compressed in the compression flow path FC1 and sent to the compressedgas circulation unit 52. A hydrate anti freezing agent is supplied from the hydrate anti freezingagent supply unit 53 to the compressedgas circulation unit 52. The hydrate anti freezing agent is sent to the gas pipeline GR together with the compressed natural gas G. In the compressedgas circulation unit 52, while preventing hydration using the supplied the hydrate anti freezing agent, the natural gas G is supplied to a natural gas G storage tank (not shown) in the ship S. - Next, a cleaning method of the
compressor 50 of the above-described embodiment will be described. In thecompressor 50 configured to compress the natural gas G and supply it to the ship S as described above, when an operation continues, sediments are precipitated and accumulate in the internal flow path FC in which the natural gas G circulates. By the cleaning method of thecompressor 50, cleaning is performed on thecompressor 50 in which such sediments accumulate. The cleaning method of thecompressor 50 of this embodiment will be described with reference toFig. 2 to Fig. 4 . - In the cleaning method of the
compressor 50 of this embodiment, as shown inFig. 4 , for a characteristic value of the natural gas G which is a gas separated out by theseparator 3 on the inlet side and the outlet side of thecompressor 50, a pressure value is measured and acquired, and a state of thecompressor 50 is measured (a characteristic value acquiring process S100). Specifically, in the characteristic value acquiring process S100, the inlet side characteristicvalue measuring unit 511 measures a pressure value of the natural gas G that circulates in thegas circulation unit 51 and acquires a pressure value of the natural gas G on the inlet side of thecompressor 50. The outlet side characteristicvalue measuring unit 521 measures a pressure value of the natural gas G that circulates in the compressedgas circulation unit 52 and acquires a pressure value of the natural gas G on the outlet side of thecompressor 50. - Next, in the cleaning method of the
compressor 50 of this embodiment, a difference between the acquired pressure value on the inlet side of thecompressor 50 and the acquired pressure value on the outlet side thereof is calculated (a difference calculating process S200). Specifically, in the difference calculating process S200, information about the pressure value measured by the inlet side characteristicvalue measuring unit 511 is input to thefirst input unit 61 of thecontrol unit 60. In the difference calculating process S200, information about the pressure value measured by the outlet side characteristicvalue measuring unit 521 is input to thesecond input unit 62 of thecontrol unit 60. In thecontrol unit 60, information input to thefirst input unit 61 and thesecond input unit 62 is input to thedifference calculation unit 63. In thedifference calculation unit 63, a difference between the pressure value on the outlet side of thecompressor 50 and the pressure value on the inlet side thereof is calculated by subtracting information input from thefirst input unit 61 from information input from thesecond input unit 62. - Next, in the cleaning method of the
compressor 50 of this embodiment, it is determined whether a hydrate anti freezing agent has been supplied to the internal flow path FC of the compressor 50 (a hydrate anti freezing agent supply determining process S300). Specifically, in the hydrate anti freezing agent supply determining process S300, thedifference calculation unit 63 determines whether a hydrate anti freezing agent has already been supplied to the internal flow path FC. In thedifference calculation unit 63, when it is determined that information has been input once from thefirst input unit 61 and thesecond input unit 62, it is determined that a hydrate anti freezing agent has already been supplied to the internal flow path FC and information about the difference is output to the secondreference determination unit 66. On the other hand, in thedifference calculation unit 63, when it is determined that information has not been input from thefirst input unit 61 and thesecond input unit 62, it is determined that a hydrate anti freezing agent has not been supplied to the internal flow path FC, and information about the difference is output to the first reference determination unit 64. - When it is determined that a hydrate anti freezing agent has not been supplied to the internal flow path FC, it is determined whether the calculated difference satisfies a predetermined first reference (a first reference determining process S400). Specifically, in the first reference determining process S400, in the
control unit 60, the calculated difference is input from thedifference calculation unit 63 to the first reference determination unit 64. The first reference determination unit 64 determines whether the input difference value is less than the first reference. When it is determined that the calculated difference is less than the first reference, the first reference determination unit 64 sends a signal to the supplystart instruction unit 65. On the other hand, when it is determined that the calculated difference is greater than the first reference, the first reference determination unit 64 terminates cleaning of thecompressor 50 without sending a signal. - When the first reference determination unit 64 determines that the difference is less than the first reference and satisfies the first reference, supply of a hydrate anti freezing agent to be supplied to a gas compressed by the
compressor 50 to the internal flow path FC starts (a supply start process S500). Specifically, in the supply start process S500, in thecontrol unit 60, a signal is sent from the first reference determination unit 64 to the supplystart instruction unit 65, and a signal is sent from the supplystart instruction unit 65 to the first supplyvalve instruction unit 68. When a signal is sent from the supplystart instruction unit 65, the first supplyvalve instruction unit 68 sends an instruction to open to thefirst supply valve 542. When thefirst supply valve 542 that has received the instruction is opened, part of the hydrate anti freezing agent that circulates in the hydrate anti freezingagent supply unit 53 flows into thefirst supply pipe 541. The hydrate anti freezing agent flowed into thefirst supply pipe 541 is sprayed from the hydrate anti freezingagent spraying unit 541a provided inside thecasing 501 toward the casing flow path FC2 and is supplied to the internal flow path FC. The hydrate anti freezing agent supplied into the internal flow path FC circulates in the internal flow path FC together with the natural gas G, flows into the compressedgas circulation unit 52, and is discharged from the inside of the internal flow path FC. - Then, pressure values of the natural gas G are measured and acquired again on the inlet side and the outlet side of the
compressor 50, and a state of thecompressor 50 is measured (the characteristic value acquiring process S100). Then, a difference between the acquired pressure value on the inlet side of thecompressor 50 and the acquired pressure value on the outlet side thereof is calculated (the difference calculating process S200). Next, it is determined whether a hydrate anti freezing agent has been supplied to the internal flow path FC of the compressor 50 (the hydrate anti freezing agent supply determining process S300). In this case, information has been already input once from thefirst input unit 61 and thesecond input unit 62. Therefore, in the hydrate anti freezing agent supply determining process S300, thedifference calculation unit 63 determines that a hydrate anti freezing agent is supplied to the internal flow path FC and outputs information about the difference to the secondreference determination unit 66. - When it is determined that a hydrate anti freezing agent is supplied to the internal flow path FC, it is determined that the calculated difference satisfies a predetermined second reference (a second reference determining process S600). Specifically, in the second reference determining process S600, in the
control unit 60, the calculated difference is input from thedifference calculation unit 63 to the secondreference determination unit 66. The secondreference determination unit 66 determines whether the input difference value is less than the second reference. When it is determined that the calculated difference is less than the second reference, the secondreference determination unit 66 sends a signal to the heatsupply instruction unit 67. On the other hand, when it is determined that the calculated difference is greater than the second reference, the secondreference determination unit 66 sends a signal to the cleaningtermination instruction unit 70, closes thefirst supply valve 542 and the second supply valve 544 and terminates cleaning of thecompressor 50. - When the second
reference determination unit 66 determines that the difference is less than the second reference and satisfies the second reference, the heated hydrate anti freezing agent is supplied to the internal flow path FC (a heat supply process S700). Specifically, in the heat supply process S700, in thecontrol unit 60, a signal is sent from the secondreference determination unit 66 to the heatsupply instruction unit 67 and a signal is sent from the heatsupply instruction unit 67 to the first supplyvalve instruction unit 68 and the second supplyvalve instruction unit 69. When the signal is sent from the heatsupply instruction unit 67, the first supplyvalve instruction unit 68 sends an instruction to close to thefirst supply valve 542. When the signal is sent from the heatsupply instruction unit 67, the second supplyvalve instruction unit 69 sends an instruction to open to the second supply valve 544. When thefirst supply valve 542 that has received the instruction is closed, the hydrate anti freezing agent flowing into thefirst supply pipe 541 is stopped. When the second supply valve 544 that has received the instruction is opened, flowing of the hydrate anti freezing agent into thesecond supply pipe 543 starts. The hydrate anti freezing agent flowed into thesecond supply pipe 543 passes through theheating unit 55 and is thus heated through heat exchange with the crude oil O that flows in theliquid circulation unit 42. The hydrate anti freezing agent heated to a high temperature flows into thefirst supply pipe 541 from a downstream side relative to thefirst supply valve 542. The high temperature hydrate anti freezing agent flowed into thefirst supply pipe 541 is sprayed from the hydrate anti freezingagent spraying unit 541a inside thecasing 501 toward the casing flow path FC2 and is supplied to the internal flow path FC. The high temperature hydrate anti freezing agent supplied into the internal flow path FC circulates in the internal flow path FC together with the natural gas G, flows into the compressedgas circulation unit 52, and is discharged from the inside of the internal flow path FC. - According to the
compressor system 5 described above, part of the hydrate anti freezing agent that is supplied from the hydrate anti freezingagent supply unit 53 to the compressedgas circulation unit 52 for preventing hydration of the natural gas G compressed by thecompressor 50 is sprayed to the casing flow path FC2 through thefirst supply pipe 541 when thefirst supply valve 542 is opened. The hydrate anti freezing agent not only prevents freezing of the natural gas G and prevents hydration but also has lipophilicity and hydrophilicity. Therefore, it is possible to remove oil contamination and aqueous contamination by the hydrate anti freezing agent. Therefore, when the hydrate anti freezing agent sprayed to the casing flow path FC2 flows in the internal flow path FC together with the natural gas G, it is possible to effectively remove sediments that are precipitated on a wall surface of the internal flow path FC. When the hydrate anti freezing agent is directly supplied to the casing flow path FC2, the hydrate anti freezing agent is prevented from being diluted by the natural gas G before reaching the internal flow path FC, and it is possible to clean the inside of thecompressor 50 by effectively using the hydrate anti freezing agent. When part of the hydrate anti freezing agent supplied from the hydrate anti freezingagent supply unit 53 to the compressedgas circulation unit 52 is used, it is possible to reliably supply a necessary amount of the hydrate anti freezing agent to the internal flow path FC. Accordingly, thecompressor 50 can be reliably and effectively cleaned. - When the
control unit 60 satisfies predetermined conditions as in the first reference determination unit 64 and the secondreference determination unit 66, the hydrate anti freezing agent flows into thefirst supply pipe 541 and thesecond supply pipe 543 from the hydrate anti freezingagent supply unit 53. As a result, the hydrate anti freezing agent is ejected into the casing flow path FC2 by the hydrate anti freezingagent spraying unit 541 a. That is, when supply of the hydrate anti freezing agent to the internal flow path FC is controlled by the first reference determination unit 64 and the secondreference determination unit 66, the hydrate anti freezing agent can be limit supply to thecompressor 50 that is in a state in which cleaning is necessary. Therefore, it is possible to efficiently use the hydrate anti freezing agent supplied from thefirst supply pipe 541 and thesecond supply pipe 543 for cleaning thecompressor 50 and minimize a supply amount of the hydrate anti freezing agent. - In the
control unit 60, a pressure value of the natural gas G on the inlet side of thecompressor 50 measured by the inlet side characteristicvalue measuring unit 511 of thegas circulation unit 51 is input to thefirst input unit 61. In addition, in thecontrol unit 60, a pressure value of the natural gas G on the outlet side of thecompressor 50 measured by the outlet side characteristicvalue measuring unit 521 of the compressedgas circulation unit 52 is input to thesecond input unit 62. Accordingly, it is possible to acquire pressure values of the natural gas G on the inlet side and the outlet side of thecompressor 50. When thedifference calculation unit 63 calculates a difference between the acquired pressure values of the natural gas G on the inlet side and the outlet side of thecompressor 50 and the first reference determination unit 64 compares the calculated difference with the first reference and performs determination, it is possible to easily determine whether the internal flow path FC is in a state in which cleaning is necessary. Based on the determination result, when a signal is sent from the first reference determination unit 64 to the supplystart instruction unit 65 and thefirst supply valve 542 is opened through the first supplyvalve instruction unit 68, it is possible to start supply of the hydrate anti freezing agent to thefirst supply pipe 541. As a result, it is possible to start spraying of the hydrate anti freezing agent from the hydrate anti freezingagent spraying unit 541 a to the internal flow path FC and it is possible to perform cleaning of the internal flow path FC. Therefore, it is possible to determine whether thecompressor 50 is in a state in which cleaning is necessary with high accuracy and it is possible to further limit supply of the hydrate anti freezing agent. Therefore, for the internal flow path FC for which cleaning is necessary, the hydrate anti freezing agent supplied from thefirst supply pipe 541 and thesecond supply pipe 543 can be more efficiently used for cleaning thecompressor 50 and it is possible to further minimize a supply amount of the hydrate anti freezing agent. - The
heating unit 55 configured to heat a hydrate anti freezing agent is provided in thesecond supply pipe 543. Therefore, it is possible to supply a high temperature hydrate anti freezing agent to the internal flow path FC. It is possible to improve solubility of sediments due to the hydrate anti freezing agent that is heated to a high temperature. Therefore, it is possible to increase a dissolution rate of sediments accumulated in the internal flow path FC and effectively clean the internal flow path FC. - When the
difference calculation unit 63 calculates a difference between the acquired pressure values of the natural gas G on the inlet side and the outlet side of thecompressor 50, and the secondreference determination unit 66 compares the calculated difference with the second reference that is set to a value greater than the first reference and performs determination, it is possible to easily determine again whether the internal flow path FC is in a state in which cleaning is necessary. Therefore, for example, it is possible to easily determine whether the internal flow path FC is in a state that is different from the state determined using the first reference (for example, whether greater cleaning is necessary for the internal flow path FC). Based on the determination result, a signal is sent from the secondreference determination unit 66 to the heatsupply instruction unit 67, thefirst supply valve 542 is closed through the first supplyvalve instruction unit 68, and the second supply valve 544 is opened through the second supplyvalve instruction unit 69. Therefore, it is possible to start supply of the hydrate anti freezing agent to thesecond supply pipe 543 in which theheating unit 55 is provided. As a result, it is possible to spray the hydrate anti freezing agent heated to a high temperature from the hydrate anti freezingagent spraying unit 541 a to the internal flow path FC, and it is possible to perform cleaning of the internal flow path FC more effectively. Therefore, it is possible to determine whether thecompressor 50 is in a state that is different from the state in which the first reference is used for determination and cleaning is performed with high accuracy and it is possible to perform greater cleaning on thecompressor 50 as necessary. Therefore, when the internal flow path FC is in a state in which greater cleaning is necessary, it is possible to efficiently supply the heated hydrate anti freezing agent and clean thecompressor 50 more efficiently. - When monoethylene glycol whose hydrocarbon part has lipophilicity and whose hydroxyl groups and ether group have hydrophilicity is used as the hydrate anti freezing agent, it is possible to effectively clean both oil contamination and aquatic contamination in the internal flow path FC.
- When part of the hydrate anti freezing agent supplied from the hydrate anti freezing
agent supply unit 53 to the compressedgas circulation unit 52 flows in the internal flow path FC of thecompressor 50 for cleaning, there is no need to stop an operation of thecompressor 50 in order to clean thecompressor 50. Therefore, it is possible to efficiently clean thecompressor 50 without causing a cleaning downtime. - According to the
subsea production system 1 described above, it is also possible to reliably and efficiently clean thecompressor 50 that is installed at a position at which maintenance is difficult, for example, in the seabed. Therefore, it is possible to prevent clogging due to sediments and it is possible to reliably send the natural gas G to the ship S through thecompressor 50. - According to the cleaning method of the
compressor 50 described above, a difference between the pressure values of the natural gas G on the inlet side and the outlet side of thecompressor 50 acquired in the characteristic value acquiringprocess S 100 is calculated in the difference calculating process S200 and it is determined whether a hydrate anti freezing agent has been supplied to the internal flow path FC in the hydrate anti freezing agent supply determining process S300. Then, in the first reference determining process S400, the calculated difference is compared with the first reference and determination is performed. Therefore, it is possible to easily determine whether the internal flow path FC is in a state in which cleaning is necessary. Based on the determination result, thefirst supply valve 542 is opened in the supply start process S500. Therefore, it is possible to start supply of the hydrate anti freezing agent to thefirst supply pipe 541. As a result, it is possible to start spraying of the hydrate anti freezing agent from the hydrate anti freezingagent spraying unit 541 a to the internal flow path FC and it is possible to perform cleaning of the internal flow path FC. Therefore, it is possible to determine whether thecompressor 50 is in a state in which cleaning is necessary with high accuracy and it is possible to further limit supply of the hydrate anti freezing agent. Therefore, for the internal flow path FC for which cleaning is necessary, the hydrate anti freezing agent supplied from thefirst supply pipe 541 and thesecond supply pipe 543 can be more efficiently used for cleaning thecompressor 50 and it is possible to further minimize a supply amount of the hydrate anti freezing agent. - After it is determined whether a hydrate anti freezing agent has been supplied to the internal flow path FC in the hydrate anti freezing agent supply determining process S300, when the second reference determining process S600 is performed in the first reference determining process S400 based on the determination result, it is possible to determine a cleaning state of the
compressor 50. Therefore, it is possible to more efficiently clean thecompressor 50 according to the cleaning state of thecompressor 50. - A difference between the pressure values of the natural gas G on the inlet side and the outlet side of the
compressor 50 acquired in the characteristic value acquiringprocess S 100 is calculated in the difference calculating process S200 and the calculated difference is compared with the second reference that is set to a value greater than the first reference and determination is performed in the second reference determining process S600. Accordingly, it is possible to easily determine again whether the internal flow path FC is in a state in which cleaning is necessary. Therefore, for example, it is possible to easily determine whether the internal flow path FC is in a state that is different from the state determined using the first reference (for example, whether greater cleaning is necessary for the internal flow path FC). Based on the determination result, in the heat supply process S700, thefirst supply valve 542 is closed and the second supply valve 544 is opened. Therefore, it is possible to start supply of the hydrate anti freezing agent to thesecond supply pipe 543 in which theheating unit 55 is provided. As a result, it is possible to spray the hydrate anti freezing agent heated to a high temperature from the hydrate anti freezingagent spraying unit 541a to the internal flow path FC, and it is possible to perform cleaning of the internal flow path FC more effectively. Therefore, it is possible to determine whether thecompressor 50 is in a state that is different from the state in which the first reference is used for determination and cleaning is performed with high accuracy and it is possible to perform greater cleaning on thecompressor 50 as necessary. Therefore, when the internal flow path FC is in a state in which greater cleaning is necessary, it is possible to efficiently supply the heated hydrate anti freezing agent and clean thecompressor 50 more efficiently. - The embodiments of the present invention have been described in detail above with reference to the drawings, but configurations and combinations thereof in the embodiments are only examples, and additions, omissions, substitutions and other modifications of the configurations can be made without departing from the scope of the present invention. In addition, the present invention is not limited to the embodiments and is only limited by the scope of the appended claims.
- A characteristic value of a gas is not limited to a pressure value of the gas as in this embodiment, and may be a value at which there is a difference in a state before and after the gas is compressed by the compressor. For example, the characteristic value of the gas may be a value obtained by measuring a temperature of the gas, a value obtained by measuring a flow rate of the gas, and a value obtained by calculating an efficiency of the
compressor 50. - The internal hydrate anti freezing
agent supply unit 54 of this embodiment has a configuration in which there is branching into thefirst supply pipe 541 and thesecond supply pipe 543, is not limited to such a structure and may have any structure as long as the hydrate anti freezing agent can be supplied to the internal flow path FC of thecompressor 50. For example, the internal hydrate anti freezingagent supply unit 54 may have a structure that includes only either thefirst supply pipe 541 or thesecond supply pipe 543. - When it is determined whether the first reference or the second reference is satisfied, determination of whether to supply the hydrate anti freezing agent may not be based on a single determination result as in this embodiment, but based on a plurality of determinations of whether the first reference or the second reference is satisfied. In such a configuration, it is possible to determine a contamination condition of the internal flow path FC with higher accuracy.
- According to the above-described compressor system, it is possible to efficiently clean the compressor by supplying the hydrate anti freezing agent to the internal flow path.
-
- 1
- Subsea production system
- S
- Ship
- F
- Oil gas field
- W
- Production well
- PF
- Production fluid
- M
- Manifold
- FL
- Flow line
- R
- Riser
- GR
- Gas pipeline
- OR
- Oil pipeline
- AR
- Pipeline for a hydrate anti freezing agent
- AL
- Umbilical line
- SM
- Subsea module
- 2
- Main heat exchanger
- 3
- Separator
- 4
- Pump system
- 41
- Pump
- 42
- Liquid circulation unit
- 43
- Compressed liquid circulation unit
- 5
- Compressor system
- 50
- Compressor
- SL
- Shaft line
- 501
- Casing
- 502
- Rotation shaft
- 503
- Impeller
- 503a
- Disk
- 503b
- Blade
- 503c
- Cover
- FC
- Internal flow path
- FC1
- Compression flow path
- FC2
- Casing flow path
- 51
- Gas circulation unit
- 511
- Inlet side characteristic value measuring unit
- 52
- Compressed gas circulation unit
- 521
- Outlet side characteristic value measuring unit
- 53
- Hydrate anti freezing agent supply unit
- 54
- Internal hydrate anti freezing agent supply unit
- 541
- First supply pipe
- 541a
- Hydrate anti freezing agent spraying unit
- 42
- First supply valve
- 543
- Second supply pipe
- 544
- Second supply valve
- 55
- Heating unit
- 60
- Control unit
- 61
- First input unit
- 62
- Second input unit
- 63
- Difference calculation unit
- 64
- First reference determination unit
- 65
- Supply start instruction unit
- 66
- Second reference determination unit
- 67
- Heat supply instruction unit
- 68
- First supply valve instruction unit
- 69
- Second supply valve instruction unit
- 70
- Cleaning termination instruction unit
- S100
- Characteristic value acquiring process
- S200
- Difference calculating process
- S300
- Hydrate anti freezing agent supply determining process
- S400
- First reference determining process
- S500
- Supply start process
- S600
- Second reference determining process
- S700
- Heat supply process
Claims (8)
- A compressor system comprising:a compressor including a casing, a rotation shaft supported in the casing, and an impeller that rotates together with the rotation shaft and compresses a gas;a compressed gas circulation unit in which the gas compressed by the compressor circulates;a hydrate anti freezing agent supply unit configured to supply a hydrate anti freezing agent that prevents hydration of the gas to the compressed gas circulation unit; andan internal hydrate anti freezing agent supply unit configured to supply part of the hydrate anti freezing agent supplied from the hydrate anti freezing agent supply unit to an internal flow path formed of the impeller and the casing.
- The compressor system according to claim 1, comprising
a control unit configured to perform supply control such that, when predetermined conditions are satisfied, the internal hydrate anti freezing agent supply unit starts supply of the hydrate anti freezing agent to the internal flow path. - The compressor system according to claim 2,
wherein the control unit includes
a first reference determination unit configured to determine whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference; and
a supply start instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to start supply of the hydrate anti freezing agent to the internal flow path when the first reference determination unit determines that the first reference is satisfied. - The compressor system according to any one of claims 1 to 3, comprising
a heating unit configured to heat the hydrate anti freezing agent,
wherein the internal hydrate anti freezing agent supply unit supplies the hydrate anti freezing agent heated by the heating unit to the internal flow path. - The compressor system according to claim 3, comprising
a heating unit configured to heat the hydrate anti freezing agent,
wherein the control unit includes
a second reference determination unit configured to determine whether a difference between characteristic values of the gas on the inlet side of the compressor and the outlet side of the compressor satisfies a predetermined second reference after supply of the hydrate anti freezing agent to the internal flow path starts; and
a heat supply instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to supply the hydrate anti freezing agent heated by the heating unit to the internal flow path when the second reference determination unit determines that the second reference is satisfied. - A subsea production system comprising:the compressor system according to any one of claims 1 to 5; anda separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.
- A compressor cleaning method in which a compressor including a casing, a rotation shaft supported in the casing and an impeller that rotates together with the rotation shaft and compresses a gas is cleaned, the method comprising:a first reference determining process of determining whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference; anda supply start process in which, when it is determined that the first reference is satisfied in the first reference determining process, supply of a hydrate anti freezing agent that prevents hydration of the gas compressed by the compressor to an internal flow path formed of the impeller and the casing starts.
- The compressor cleaning method according to claim 7, comprising
a second reference determining process in which, after supply of the hydrate anti freezing agent to the internal flow path starts, it is determined whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined second reference; and
a heat supply process in which, when it is determined that the second reference is satisfied in the second reference determining process, the heated hydrate anti freezing agent is supplied to the internal flow path.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014147603A JP2016023578A (en) | 2014-07-18 | 2014-07-18 | Compressor system, undersea production system with compressor system, and compressor system washing method |
PCT/JP2015/051529 WO2016009658A1 (en) | 2014-07-18 | 2015-01-21 | Compressor system, subsea production system provided therewith, and compressor cleaning method |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3156665A1 true EP3156665A1 (en) | 2017-04-19 |
EP3156665A4 EP3156665A4 (en) | 2017-07-19 |
Family
ID=55078164
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP15821658.0A Withdrawn EP3156665A4 (en) | 2014-07-18 | 2015-01-21 | Compressor system, subsea production system provided therewith, and compressor cleaning method |
Country Status (5)
Country | Link |
---|---|
US (1) | US20170198724A1 (en) |
EP (1) | EP3156665A4 (en) |
JP (1) | JP2016023578A (en) |
CN (1) | CN106489029A (en) |
WO (1) | WO2016009658A1 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6735978B2 (en) * | 2018-03-12 | 2020-08-05 | 国立研究開発法人産業技術総合研究所 | Gas production system and gas production method |
JP6735979B2 (en) * | 2018-03-12 | 2020-08-05 | 国立研究開発法人産業技術総合研究所 | Gas production system and gas production method |
IT201900023883A1 (en) * | 2019-12-13 | 2021-06-13 | Nuovo Pignone Tecnologie Srl | COMPRESSOR WITH A SYSTEM TO REMOVE LIQUID FROM THE COMPRESSOR |
US11391289B2 (en) * | 2020-04-30 | 2022-07-19 | Trane International Inc. | Interstage capacity control valve with side stream flow distribution and flow regulation for multi-stage centrifugal compressors |
US11536277B2 (en) | 2020-04-30 | 2022-12-27 | Trane International Inc. | Interstage capacity control valve with side stream flow distribution and flow regulation for multi-stage centrifugal compressors |
US11841026B2 (en) | 2021-11-03 | 2023-12-12 | Trane International Inc. | Compressor interstage throttle, and method of operating therof |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NO324110B1 (en) * | 2005-07-05 | 2007-08-27 | Aker Subsea As | System and process for cleaning a compressor, to prevent hydrate formation and/or to increase compressor performance. |
US7784288B2 (en) * | 2006-03-06 | 2010-08-31 | General Electric Company | Methods and systems of variable extraction for compressor protection |
WO2007110368A1 (en) * | 2006-03-24 | 2007-10-04 | Siemens Aktiengesellschaft | Method for operating a compressor unit and associated compressor unit |
JP5675121B2 (en) * | 2010-01-27 | 2015-02-25 | 三菱重工業株式会社 | Centrifugal compressor and cleaning method |
MX356834B (en) * | 2012-06-11 | 2018-06-15 | Statoil Petroleum As | Subsea compressor cleaning method wherein the cleaning liquid is retrieved from the multiphase process fluid. |
JP2014128104A (en) * | 2012-12-26 | 2014-07-07 | Mitsubishi Heavy Ind Ltd | Compression system |
-
2014
- 2014-07-18 JP JP2014147603A patent/JP2016023578A/en not_active Withdrawn
-
2015
- 2015-01-21 US US15/326,858 patent/US20170198724A1/en not_active Abandoned
- 2015-01-21 CN CN201580037321.1A patent/CN106489029A/en active Pending
- 2015-01-21 WO PCT/JP2015/051529 patent/WO2016009658A1/en active Application Filing
- 2015-01-21 EP EP15821658.0A patent/EP3156665A4/en not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
JP2016023578A (en) | 2016-02-08 |
US20170198724A1 (en) | 2017-07-13 |
CN106489029A (en) | 2017-03-08 |
WO2016009658A1 (en) | 2016-01-21 |
EP3156665A4 (en) | 2017-07-19 |
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