CN112267854A - Device and process for exploiting deep sea combustible ice by adopting decompression method - Google Patents
Device and process for exploiting deep sea combustible ice by adopting decompression method Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 37
- 230000008569 process Effects 0.000 title claims abstract description 20
- 230000006837 decompression Effects 0.000 title claims description 5
- 239000004576 sand Substances 0.000 claims abstract description 130
- 239000007788 liquid Substances 0.000 claims abstract description 68
- 238000005065 mining Methods 0.000 claims abstract description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 65
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
- E21B43/02—Subsoil filtering
- E21B43/04—Gravelling of wells
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
- E21B43/02—Subsoil filtering
- E21B43/08—Screens or liners
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
- E21B43/38—Arrangements for separating materials produced by the well in the well
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Abstract
The invention relates to a device and a process for exploiting deep sea combustible ice by adopting a pressure reduction method, and belongs to the technical field of ocean oil and gas resource exploitation. The technical key points are as follows: the system comprises an exploitation platform, a wellhead device, a casing string, an exploitation pipe column, an underground sand removal system, a monitoring system, an underwater conveying pipeline and an umbilical cable; and by adopting three-stage sand prevention and two-stage sand removal measures, the sand prevention and removal can be effectively carried out, and the stable exploitation of the combustible ice is ensured. Two gas-liquid separators, namely a tubular column rotational flow gas-liquid separator and a filler gas-liquid separator, are arranged on the mining tubular column, so that high-efficiency separation in a gas-liquid well is realized, and more thorough gas-liquid separation is ensured. The electric submersible pump is arranged below the mining layer, so that gas is guaranteed to rapidly enter the mining pipe column, a reliable guarantee is provided for water suction of the pump, and cavitation and idle running of the pump are avoided. The water is heated by the heat productivity of the electric submersible pump motor, so that the generation of hydrate is avoided.
Description
Technical Field
The invention relates to a method for exploiting deep-sea combustible ice, and belongs to the technical field of ocean oil and gas resource exploitation.
Background
Along with the industrial development, the energy consumption is more and more, and human beings face the energy crisis in the beginning of the 21 st century, and as the countries of energy consumption, the crude oil import in China is more than one hundred million tons per year, the output of land oil and gas fields in China is reluctantly stable, and experts are estimated to hardly have major breakthrough in a short time. Natural gas hydrates, which are capable of burning ice, are gaining favor as an alternative green clean energy source in all countries of the world. The storage amount of combustible ice mineral deposits in the world is 2 times of that of combustible minerals such as petroleum; statistically, about 71% of natural gas hydrates are distributed in the ocean on the earth. The oil equivalent combustible ice storage capacity of 650-800 million tons is expected in south China sea area.
The combustible ice is taken as unconventional energy, is greatly different from the conventional energy in the exploitation phase state and the energy utilization form, and the oil and the natural gas are exploited to utilize the energy of the oil and the natural gas without the change of the phase state. The combustible ice is a solid crystalline substance, and the combustible ice is decomposed into natural gas and water in the mining process, namely, the phase state conversion is carried out, and the energy utilization form of the combustible ice is only natural gas.
The deep sea combustible ice deposit is generally positioned in the water depth of 500-1000 m below the water and the range of 200-500 m below the mud surface. According to the related data, the burial depth of the combustible ice is mainly concentrated on a silt reservoir, the stratum is easy to generate sand, production equipment and flow blockage are easy to cause, and higher requirements are provided for the processing capacity of the mining ground metering equipment.
The exploitation of deep sea combustible ice has many methods, such as depressurization, heating, inhibitor, replacement, etc. The depressurization method has the advantages of simple equipment, low cost, convenient operation and the like, and is the most potential mining mode at present, namely, the submersible pump is used for pumping and discharging internal liquid, so that the formation pressure is reduced, natural gas hydrate is decomposed, and decomposed gas and water rise to a water surface mining platform along a shaft under the extraction of the pump, thereby realizing the continuous production of natural gas.
The pressure reduction exploitation of combustible ice is an exploitation method for controlling reservoir pressure and further controlling hydrate decomposition by adjusting the extraction speed of natural gas. Because the sand production phenomenon inevitably occurs in the process of hydrate depressurization production, part of formation sand flowing into the shaft is carried to the wellhead of the platform by fluid, and part of formation sand is deposited in the shaft. In the actual trial production process of the marine natural gas hydrate, well shaft sand burying occurs rapidly due to the fact that a large amount of sand is produced in an over-destructive mode, sand production of the stratum is aggravated at a high pressure reduction rate, and other engineering problems are caused. Meanwhile, the submersible pump conveys mixed liquid of water and sand for a long time, and parts such as a water pump impeller and a seal are seriously abraded, so that unpredictable faults can occur in long-term operation.
Disclosure of Invention
The invention aims to solve the defects of the prior art and provide a depressurization mining process which is suitable for a deep-sea combustible ice mining environment and can effectively prevent the problems of sediment accumulation, blockage, equipment abrasion and the like in the mining process.
In order to achieve the purpose, the technical scheme of the invention is as follows: a device and a process for exploiting deep sea combustible ice by a decompression method comprise an exploitation platform, a wellhead device, a casing string, an exploitation pipe column, an underground sand removal system, a monitoring system, an underwater conveying pipeline and an umbilical cable;
the process comprises the following steps:
1. and (3) a well completion scheme: drilling to the lower part of a combustible ice target exploitation layer, and reserving installation spaces of the electric submersible pump set and the underground sand removal system; in order to ensure the permeability of a mining layer, filtering larger sand and stone and preventing the sand and stone from entering a mining shaft to cause unstable structure of the mining layer, filling gravel into a space between a combustible ice mining layer and a mining casing pipe, arranging a primary sand filter net on the casing pipe at the combustible ice mining layer section, cementing a casing pipe column after the gravel filling is finished, and arranging an artificial shaft bottom;
2. a bottom hole pressure sensor, a jet flow sand removal pump and a pipeline are arranged in the casing string, and the bottom hole pressure sensor and the jet flow sand removal pump are arranged at the bottom of the exploitation well;
3. a production pipe column which is designed and provided with a cyclone sand remover, an electric submersible pump set, a secondary sand prevention net, a gas-liquid separator set, a natural gas conveying pipe and a production water conveying sea pipe according to the actual working condition of a production well is put in;
4. installing a packer and a wellhead device; installing facilities such as a water and gas conveying sea pipe, an umbilical cable and the like, and connecting the facilities to an exploitation platform;
5. after all facilities are installed, starting the electric submersible pump to perform drainage and depressurization operation, monitoring the pressure and temperature in a production well through a pressure and temperature sensor in the well, monitoring the liquid level in the well through a liquid level sensor, controlling the pressure in the well by controlling the discharge capacity of the electric submersible pump and the gas production rate of natural gas, enabling the pressure condition of a hydrate of a combustible ice production layer to be in a gas phase state of a phase balance curve, promoting the combustible ice to be decomposed, enabling natural gas and water generated by decomposition to enter a production string well through a gravel filling layer, a primary sand filtering net and a secondary sand preventing net, enabling the natural gas to upwards pass through a gas-liquid separator group for dewatering, and then discharging the natural gas to a platform natural gas treatment module; the production water is discharged to a production water treatment module of the mining platform for treatment through an electric submersible pump set, a production water conveying pipe and a wellhead device after silt is removed through a cyclone desander; the sand deposition in the well is provided with sand removing power water for the jet flow sand removing pump by a sand removing power water module on the mining platform, and the sand deposition at the bottom of the well is discharged to a sand processing module of the mining platform through a sand discharge pipe under the action of stirring and negative pressure of the power water of the jet flow sand removing pump for processing.
Due to the adoption of the technical scheme, the invention has the following advantages and effects:
1. and by adopting three-stage sand prevention and two-stage sand removal measures, the sand prevention and removal can be effectively carried out, and the stable exploitation of the combustible ice is ensured. The third-level sand control is a gravel filling layer, a primary sand filtering net and a secondary sand control net; the second-stage sand removal is a rotational flow sand remover and a jet flow sand removal pump in front of the electric submersible pump. The gravel filling layer and the primary sand filtering net can effectively prevent large gravel in the mining layer from flowing, and simultaneously ensure the porosity of the mining layer, so that water and natural gas in the mining layer can flow conveniently, and the stable yield effect of combustible ice is achieved. The cyclone sand remover in front of the electric submersible pump can effectively remove silt in production water and reduce the abrasion and blockage of the silt of the electric submersible pump and a production water pipeline, thereby prolonging the service life of mining equipment. The jet sand removing pump can discharge sediment deposited in the well bottom, and the well repairing work in the later period of lightening the well burying caused by the sediment of the sediment during the long-term operation of the exploitation well is avoided. In addition, the jet flow sand removing pump has the characteristics of simple structure, no moving part and no maintenance.
2. The gas-liquid mixed gas enters from the bottom of the tubular column rotational flow gas-liquid separator, the gas rotates at high speed to go upwards under the action of the spiral groove and the rotational flow guide plate in the rotational flow separator, and the liquid flows to the exploitation pipe wall and stays to the bottom along the pipe wall under the action of centrifugal force and weight, so that the simple and efficient separation of gas and liquid is realized. In order to further guarantee the gas-liquid separation effect, a filler gas-liquid separator is additionally arranged at the upper end of the tubular column rotational flow gas-liquid separator, and gas-liquid separation is carried out on the gas-liquid mixed gas again by utilizing the inertia of liquid and the aggregation of the filler. Thereby ensuring more thorough gas-liquid separation.
3. The electric submersible pump is arranged below the mining layer, so that the electric submersible pump can be effectively ensured to be positioned below the water surface, a sufficient separation space is reserved for the gas-liquid separation cavity, and gas can be ensured to rapidly enter the mining pipe column. Meanwhile, a reliable guarantee is provided for the water sucked by the pump, and the cavitation and the idle running of the pump are avoided.
4. In addition, the heat generated by the electric submersible pump motor can be used for heating the production water in the shaft, so that the generation of hydrate is avoided.
Drawings
FIG. 1 is a schematic view of the overall structure of the present invention
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
the device and the process for exploiting the deep sea combustible ice by adopting the decompression method are shown in figure 1 and comprise an exploitation platform 1, a wellhead device 2, a casing string 3, an exploitation pipe string 4, an underground sand removal system 5, a monitoring system 6, underwater conveying pipelines 21, 22, 23 and 24 and an umbilical cable 25; the method is characterized in that:
the production platform 1 is located at the sea surface as shown in figure 1, a natural gas processing module 11, a production water processing module 12, a sediment processing module 14 and a sand removal power water module 15 on the production platform 1 are respectively connected with a wellhead device 2 located on an underwater seabed through underwater conveying pipelines 21, 22, 23 and 24, the lower part of the wellhead device 2 is installed at the upper end of a casing string 3 of a production well and is connected with a production pipe string 4 and an underground sand removal system 5 in the casing string, so that natural gas, production water and sediment produced in the well are conveyed to corresponding modules of the production platform 1 for processing, meanwhile, a monitoring module 13 on the production platform 1 is connected with detection sensors 61, 62 and 63 in the well through umbilical cables 25, and the liquid level, temperature, pressure conditions and working conditions in the well in the production process are monitored;
the wellhead assembly 2 is shown in figure 1 for connection to subsea conveying conduits 21, 22, 23, 24 and umbilical 25 at the seabed and is connected at its lower end to a casing string 3, a production string 4 and a downhole sand removal system 5 in a production well. The control and regulation of the equipment in the well are realized through the wellhead device 2;
the casing string 3 is shown in figure 1 as terminating through the producing formation 103 and running into the lower cladding 104. It is composed of a surface casing 31, a production casing 32 and a primary sand screen 33; the upper end of the casing string 3 is connected with the lower end of the wellhead device 2 and penetrates through the upper cladding 102 and the mining layer 103, the tail end of the production casing 32 is positioned in the lower cladding 104 at the lower part of the mining layer, a sieve pore structure is adopted at the mining layer, a primary sand prevention net 33 is arranged, and a steel wire gauze structure is adopted to filter large-particle sediment; arranging a production pipe column 4 and a downhole sand removing system 5 in an inner space defined by the casing strings 3; the casing string 3 can realize the functions of sealing various stratums, stabilizing the well wall, establishing the internal space of the shaft, filtering sediment and installing a wellhead device;
as shown in fig. 1, the mining pipe column 4 adopts a structure design that the pipe column at the position of the combustible ice layer adopts a sieve pore structure and is provided with a sand prevention net, and meanwhile, an electric submersible pump set 45 is arranged at the lower part of the mining layer; the production pipe column 4 consists of a production water conveying pipe 41, a natural gas conveying pipe 42, a gas-liquid separator group 43, a secondary sand prevention net 44, an electric submersible pump group 45 and a cyclone desander 46; the connection relationship is that the cyclone desander 46 is arranged at the lowest end of the mining pipe column, the upper end of the cyclone desander is connected with the suction inlet of the electric submersible pump set 45, the discharge pipeline of the submersible pump set is a production water conveying pipe 41, and the upper end of the submersible pump set is connected with a wellhead device; the mining pipe column on the mining layer 103 at the upper part of the electric submersible pump unit 45 adopts a sieve mesh structure and is provided with a secondary sand control net 44 with multiple layers of steel wires, so that sand is further isolated from entering the mining pipe column 4, water and natural gas can smoothly enter an annular space formed by the mining pipe column 4 and the production water conveying pipe 41 through the secondary sand control net, the natural gas flows upwards and is separated from water carried by the natural gas through a gas-liquid separator group 43 arranged on the mining pipe column, and the separated natural gas continues to form an annular space between the mining pipe column 4 and the production water conveying pipe 41 upwards to serve as a natural gas conveying pipe 42 and is communicated with the wellhead device 2, so that the natural gas and the water are separated in the well; the cyclone desander 46 is of a conical structure, the upper end of the cyclone desander is provided with a liquid outlet which is connected with a suction inlet of the submersible pump set, and the lower end of the cyclone desander is provided with a sand outlet which is used for discharging separated silt to the outside of the production pipe column; a liquid inlet is arranged on the upper pipe wall along the tangential direction of the pipe wall, a spiral groove is arranged on the inner wall of the pipe, sand-containing well liquid enters the desander along the tangential port under the suction action of the electric submersible pump, the liquid rotates to generate centrifugal force under the action of the spiral groove, so that the sand with high density is discharged from a bottom discharge port along the pipe wall, and the purified well liquid in the middle upwards enters an electric submersible pump set 45; the electric submersible pump set 45 is important equipment for mining a pipe column, and the depressurization mining of the combustible ice is realized by draining water through the submersible pump set, so that the condition of the combustible ice is destroyed and the combustible ice is decomposed to form natural gas and water, and the purpose of mining is achieved; the electric submersible pump group 45 consists of three parts, namely an electric submersible pump motor 453, an electric submersible pump inlet and housing 452 and an electric submersible pump body 451 from bottom to top; the annular space between the electric submersible pump motor 453 and the electric submersible pump inlet and housing 452 is the suction channel of the electric submersible pump, which can cool the electric submersible pump motor; the gas-liquid separator group 43 is arranged for realizing separation in a gas-liquid well, the gas-liquid separator group 43 consists of two parts, the lower part is a tubular column cyclone gas-liquid separator 432, and the upper part is a filler gas-liquid separator 431; the tubular column cyclone gas-liquid separator 432 is arranged on the inner wall of an exploitation tubular column, a gas channel in the separator is provided with a cyclone guide plate, gas-liquid mixture is rotated under the action of the cyclone guide plate in the process of exhausting the gas-liquid mixture from bottom to top, and liquid carried by natural gas is driven to the tubular wall and flows downwards along the tubular wall in the liquid part at the bottom; the natural gas separated by the tubular column rotational flow gas-liquid separator 432 enters the filler gas-liquid separator 431 at the upper part, and liquid carried by the natural gas is filtered and separated out through the filler again, so that the gas-liquid separation efficiency is improved, the gas-liquid separation is more thorough, the liquid carrying capacity of the natural gas is reduced, and the reliability of natural gas conveying is ensured;
the underground sand removing system 5 is shown in figure 1, adopts an independent underground sand removing system design, utilizes a jet pump to discharge underground sediment, has no mechanical moving parts and electric power, has simple structure and high reliability, and can effectively control the accumulation of the underground sediment; it is composed of a sand removing power water pipe 51, a sand discharging pipe 52 and a jet flow sand removing pump 53; the connection relationship is that a jet flow sand removal pump 53 is arranged at the bottom of a shaft and is connected to a wellhead device through a sand removal power water pipe 51 and a sediment discharge pipe 52 which are arranged inside a casing string; the sand removal power water module 15 on the mining platform 1 provides jet flow power high-pressure water for the jet flow sand removal pump 53 through the sand removal power water pipe 24 and the sand removal power water pipe 51, and silt deposited at the bottom of the well is discharged to the silt processing module 14 on the mining platform for separation processing through the silt discharge pipe 52 and the silt discharge conveying sea pipe 23 by the disturbance of the power water and the suction action of the jet flow sand removal pump 53;
the monitoring system 6 is composed of a bottom hole pressure sensor 63 arranged at the bottom of a production well, a liquid level sensor 62 positioned at a production layer, a temperature and pressure sensor 61 positioned at the upper part of a production string and a monitoring module 13 on a production platform, as shown in figure 1; monitoring the sand accumulation condition in the shaft through a bottom hole pressure sensor 63, and starting a jet flow sand removal pump to perform sand removal operation when a set value is reached; the liquid level in the well is monitored by a liquid level sensor 62 arranged on a mining layer, and the liquid level in the well is kept in a reasonable range by controlling the drainage of an electric submersible pump; the pressure and the temperature in the well are monitored through a temperature and pressure sensor 63 arranged at the upper part of the gas-liquid separator, and the pressure in the well is controlled by adjusting the flow of the gas production valve and the discharge capacity of the electric submersible pump;
the process comprises the following steps:
1. and (3) a well completion scheme: drilling to the lower part of a target combustible ice exploitation layer, and reserving installation spaces of the electric submersible pump unit 45 and the underground sand removal system 5; in order to ensure the permeability of a mining layer, filter larger sand and stone and prevent the unstable structure of the mining layer caused by entering a mining shaft, gravel filling 44 is adopted for the space between a combustible ice mining layer and a mining casing pipe, a primary sand filter net 33 is arranged on the casing pipe at the combustible ice mining layer section, after the gravel filling is finished, the casing pipe column 3 is well-fixed, and an artificial shaft bottom is arranged;
2. a bottom hole pressure sensor 63, a jet flow sand removal pump 53 and a pipeline are put into the casing string, and the bottom hole pressure sensor 63 and the jet flow sand removal pump 53 are arranged at the bottom of the production well;
3. and (3) putting the production string which is designed and provided with a cyclone sand remover 46, an electric submersible pump set 45, a secondary sand control net 44, a gas-liquid separator set 43, a natural gas conveying pipe 42 and a production water conveying marine pipe 41 according to the actual working condition of the production well.
4. Installing a packer 7 and a wellhead device 2; installing water and gas transmission sea pipes 21, 22, 23 and 24, an umbilical 25 and the like and connecting the sea pipes to the mining platform 1;
5. after all facilities are installed, starting the electric submersible pump 45 to perform drainage and depressurization operation, monitoring the pressure and temperature in a production well through the pressure and temperature sensor 61 in the well, monitoring the liquid level in the well through the liquid level sensor 62, controlling the pressure in the well through controlling the discharge capacity of the electric submersible pump 45 and the gas production rate of natural gas, enabling the pressure condition of a hydrate of a combustible ice production layer to be in a phase equilibrium curve gas phase state, promoting the decomposition of combustible ice, enabling the decomposed natural gas and water to enter the production string well through the gravel filling layer 8, the primary sand filter net 9 and the secondary sand control net 44, enabling the natural gas to upwards pass through the gas-liquid separator group 43 to remove water, and then discharging the water to the platform natural gas treatment module 11 through the natural gas conveying pipe 42; the produced water is discharged to a production water treatment module 12 of the mining platform for treatment by an electric submersible pump set 45, a production water conveying pipe (41) and a wellhead device (2) after silt is removed by a cyclone desander 46; the sand deposition in the well is provided with sand removing power water for the jet flow sand removing pump 53 by the sand removing power water module 15 on the mining platform, and the sand deposition at the bottom of the well is discharged to the sand treatment module 14 of the mining platform through the sand discharge pipe 52 for treatment under the action of the stirring and negative pressure of the power water of the jet flow sand removing pump 53.
Claims (7)
1. A device and a process for exploiting deep sea combustible ice by a decompression method are characterized in that: the system comprises a production platform (1), a wellhead device (2), a casing string (3), a production string (4), a downhole sand removal system (5), a monitoring system (6), underwater conveying pipelines (21, 22, 23 and 24) and an umbilical cable (25); the process comprises the following steps:
(1) and (3) a well completion scheme: drilling to the lower part of a combustible ice target exploitation layer, and reserving installation spaces of the electric submersible pump set (45) and the underground sand removal system (5); filtering larger sand and stone to prevent the unstable structure of a mining layer caused by entering a mining shaft, filling gravel (44) in a space between the combustible ice mining layer and a mining casing, arranging a primary sand filter net (33) on the casing of the combustible ice mining layer, cementing a casing string (3) after the gravel filling is finished, and arranging an artificial shaft bottom;
(2) a bottom hole pressure sensor (63), a jet flow sand removal pump (53) and a pipeline are put into the casing string, and the bottom hole pressure sensor (63) and the jet flow sand removal pump (53) are arranged at the bottom of the production well;
(3) a production pipe column which is designed and provided with a cyclone sand remover (46), an electric submersible pump set (45), a secondary sand control net (44), a gas-liquid separator set (43), a natural gas conveying pipe (42) and a production water conveying sea pipe (41) according to the actual working condition of a production well is put in;
(4) installing a packer (7) and a wellhead device (2); installing water and gas transmission sea pipes (21, 22, 23, 24), an umbilical (25) and the like and connecting the sea pipes to the production platform (1);
(5) after all facilities are installed, an electric submersible pump (45) is started to perform drainage and depressurization operation, the pressure and temperature in a production well are monitored through a pressure and temperature sensor (61) in the well, the liquid level in the well is monitored through a liquid level sensor (62), the pressure in the well is controlled through controlling the discharge capacity of the electric submersible pump (45) and the gas production rate of natural gas, so that the pressure condition of a hydrate of a combustible ice production layer is in a phase equilibrium curve gas phase state, combustible ice is decomposed, and natural gas and water generated by decomposition enter a production tubular column well through a gravel filling layer (8), a primary sand filter net (9) and a secondary sand prevention net (44), and the natural gas is discharged to a platform natural gas treatment module (11) through a natural gas conveying pipe (42) and a wellhead device (2) after being dewatered by a gas-liquid separator group (43; the produced water is discharged to a produced water treatment module (12) of the mining platform for treatment through an electric submersible pump set (45), a produced water conveying pipe (41) and a wellhead device (2) after silt is removed through a cyclone desander (46); the sand deposition in the well is provided with sand removing power water for the jet flow sand removing pump (53) by a sand removing power water module (15) on the mining platform, and the sand deposition at the bottom of the well is discharged to a sand treatment module (14) of the mining platform for treatment through a sand discharge pipe (52) under the action of stirring and negative pressure of the power water of the jet flow sand removing pump (53).
2. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the production platform (1) is located on the sea surface, a natural gas processing module (11), a production water processing module (12), a sediment processing module (14) and a sand removal power water module (15) on the production platform (1) are respectively connected with a wellhead device (2) located on an underwater seabed through underwater conveying pipelines (21, 22, 23 and 24), the lower part of the wellhead device (2) is installed at the upper end of a casing string (3) of a production well and is connected with a production pipe string (4) and an underground sand removal system (5) in the casing string, so that natural gas, production water and sediment produced in the well are conveyed to corresponding modules of the production platform (1) for processing, meanwhile, a monitoring module (13) on the production platform (1) is connected with detection sensors (61, 62 and 63) in the well through an umbilical cable (25), and the liquid level, temperature and sand in the well in the production process are monitored, Pressure conditions and operating conditions.
3. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the wellhead device (2) is used for connecting with underwater conveying pipelines (21, 22, 23, 24) and an umbilical cable (25) on the seabed, and the lower end of the wellhead device is connected with a casing string (3), a production pipe string (4) and a downhole sand removal system (5) in a production well; the control and adjustment of the equipment in the well are realized through the wellhead device (2).
4. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the casing string (3) adopts a design which penetrates through a producing layer (103) to terminate and is arranged in a lower cladding (104); which consists of a surface casing (31), a production casing (32) and a primary sand screen (33); the upper end of the casing string (3) is connected with the lower end of the wellhead device (2) and penetrates through the upper cladding (102) and the production layer (103), the tail end of the production casing (32) is positioned in the lower cladding (104) at the lower part of the production layer, a sieve pore structure is adopted at the production layer, a primary sand prevention net (33) is arranged, and the primary sand prevention net adopts a steel wire gauze structure; a production string (4) and a downhole sand removal system (5) are arranged in an inner space enclosed by the casing string (3).
5. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the mining pipe column (4) adopts a structure design that the pipe column at the position of the combustible ice layer adopts a sieve pore structure and is provided with a sand prevention net, and meanwhile, the electric submersible pump set (45) is arranged at the lower part of the mining layer; the production pipe column (4) consists of a production water conveying pipe (41), a natural gas conveying pipe (42), a gas-liquid separator group (43), a secondary sand control net (44), an electric submersible pump group (45) and a cyclone sand remover (46); the connection relationship is that a cyclone sand remover (46) is arranged at the lowest end of the mining pipe column, the upper end of the cyclone sand remover is connected with a suction inlet of an electric submersible pump set (45), a discharge pipeline of the submersible pump set is a production water conveying pipe (41), and the upper end of the submersible pump set is connected with a wellhead device; a mining pipe column positioned at a mining layer (103) at the upper part of the electric submersible pump set (45) adopts a sieve pore structure and is provided with a secondary sand control net (44) of a plurality of layers of steel wires; the cyclone desander (46) is of a conical structure, the upper end of the cyclone desander is provided with a liquid outlet which is connected with a suction inlet of the submersible pump set, and the lower end of the cyclone desander is provided with a sand outlet; the electric submersible pump set (45) is important equipment for a mining pipe column, and the electric submersible pump set (45) consists of an electric submersible pump motor (453), an electric submersible pump inlet and housing (452) and an electric submersible pump body (451) from bottom to top; the annular space between the electric submersible pump motor (453) and the inlet of the electric submersible pump and the housing (452) is the suction channel of the electric submersible pump; the gas-liquid separator group (43) consists of two parts, wherein the lower part is a tubular column cyclone gas-liquid separator (432) and the upper part is a filler gas-liquid separator (431); the tubular column cyclone gas-liquid separator (432) is disposed on the inner wall of the production tubular column.
6. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the underground sand removing system (5) adopts an independent shaft bottom sand removing system design and consists of a sand removing power water pipe (51), a sediment discharge pipe (52) and a jet flow sand removing pump (53); the connection relationship is as follows: the jet flow sand removal pump (53) is arranged at the bottom of the well shaft and is connected to a wellhead device through a sand removal power water pipe (51) and a sediment discharge pipe (52) which are arranged inside the casing string.
7. The device and the process for exploiting deep sea combustible ice by depressurization method according to claim 1 are further characterized in that: the monitoring system (6) consists of a bottom hole pressure sensor (63) arranged at the bottom of the production well, a liquid level sensor (62) positioned at a production layer, a temperature and pressure sensor (61) positioned at the upper part of the production string and a monitoring module (13) on the production platform.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112502673A (en) * | 2021-02-01 | 2021-03-16 | 西南石油大学 | Natural gas hydrate normal position is gathered separation and is backfilled integration instrument |
| CN113092732A (en) * | 2021-05-07 | 2021-07-09 | 青岛理工大学 | Natural gas hydrate exploitation simulation and sand production and prevention experimental method |
| CN113123763A (en) * | 2021-04-13 | 2021-07-16 | 上海万维亿通装备制造有限公司 | Combustible ice mining system and process |
| CN115680573A (en) * | 2022-10-27 | 2023-02-03 | 大连理工大学 | Natural gas hydrate exploitation device and method based on thermodynamic driving force optimization |
| CN117531300A (en) * | 2024-01-09 | 2024-02-09 | 盘锦华晨石油装备制造有限公司 | Sand outlet detection equipment for gas well |
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- 2020-11-20 CN CN202011316569.0A patent/CN112267854A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112502673A (en) * | 2021-02-01 | 2021-03-16 | 西南石油大学 | Natural gas hydrate normal position is gathered separation and is backfilled integration instrument |
| CN112502673B (en) * | 2021-02-01 | 2021-06-22 | 西南石油大学 | Natural gas hydrate normal position is gathered separation and is backfilled integration instrument |
| US11434727B2 (en) | 2021-02-01 | 2022-09-06 | Southwest Petroleum University | In situ exploitation-separation-backfilling integration apparatus used for natural gas hydrates |
| CN113123763A (en) * | 2021-04-13 | 2021-07-16 | 上海万维亿通装备制造有限公司 | Combustible ice mining system and process |
| CN113123763B (en) * | 2021-04-13 | 2024-01-26 | 上海万维亿通装备制造有限公司 | Combustible ice exploitation system and process |
| CN113092732A (en) * | 2021-05-07 | 2021-07-09 | 青岛理工大学 | Natural gas hydrate exploitation simulation and sand production and prevention experimental method |
| CN115680573A (en) * | 2022-10-27 | 2023-02-03 | 大连理工大学 | Natural gas hydrate exploitation device and method based on thermodynamic driving force optimization |
| CN115680573B (en) * | 2022-10-27 | 2024-03-22 | 大连理工大学 | Natural gas hydrate exploitation device and method based on thermodynamic driving force optimization |
| CN117531300A (en) * | 2024-01-09 | 2024-02-09 | 盘锦华晨石油装备制造有限公司 | Sand outlet detection equipment for gas well |
| CN117531300B (en) * | 2024-01-09 | 2024-03-08 | 盘锦华晨石油装备制造有限公司 | Sand outlet detection equipment for gas well |
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