Natural gas wellhead LNG (Liquefied Natural Gas) station yard

Abstract

The utility model discloses a natural gas well mouth LNG station yard which comprises a drilling platform, the drilling platform is surrounded by a fence, a gate is arranged at the near end of the drilling platform, a well mouth area, a main process area, a public auxiliary area and a loading area are arranged on the drilling platform, and equipment of the well mouth area comprises a gas production tree, a high-pressure sand remover, a water jacket furnace heating separation metering pry and a sewage tank; equipment of the main process area comprises a natural gas dehydration and demercuration pry, a natural gas deacidification pry, an MR low-pressure compressor pry, an MR high-pressure compressor pry, a cold box, an MR buffer tank, a fuel gas tank and a busbar pry. Equipment of the public and auxiliary area comprises a boosting power distribution pry, a DCS cabinet room, a high-voltage power distribution pry, a low-voltage power distribution pry, an air pressure nitrogen generation pry, an instrument air storage tank, a cooling water circulating pump pry, a cooling water tower, a desalted water pry and a DCS control room. Equipment of the loading area comprises an LNG loading pry and an LNG tank car. The natural gas wellhead LNG station yard is compact and reasonable in arrangement.

Description

Technical Field

[0001] This utility model relates to the field of natural gas equipment, specifically to LNG stations at natural gas wellheads. Background Technology

[0002] A natural gas wellhead LNG terminal includes: a drilling platform enclosed by a fence, on which are installed a gas production tree, high-pressure desander, water jacket furnace heating, separation, and metering skid, wastewater tank, natural gas dehydration and mercury removal skid, natural gas deacidification skid, MR low-pressure compressor skid, MR high-pressure compressor skid, cold box, MR buffer tank, fuel gas tank, booster distribution skid, DCS cabinet room, high-pressure distribution skid, low-pressure distribution skid, instrument air storage tank, cooling water circulation pump skid, cooling tower, demineralized water skid, DCS control room, LNG loading skid, and LNG tank trucks. The existing layout of natural gas wellhead LNG terminals has many unreasonable aspects, resulting in a large footprint and significantly increasing the amount of materials used for pipelines, steel structures, and instrumentation cables. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a compact and reasonable layout for a natural gas wellhead LNG station.

[0004] To solve the above problems, the technical solution adopted by this utility model is as follows: a natural gas wellhead LNG station, including: a drilling platform, which is surrounded by a fence, with a gate at the near end of the drilling platform. The feature is that the drilling platform is equipped with a wellhead area, a main process area, a public auxiliary area, and a loading area. The equipment in these four areas is interconnected via pipe corridors. The equipment in the wellhead area includes: a gas production tree, a high-pressure desander, a water jacket furnace heating, separation, and metering skid, and a wastewater tank; the equipment in the main process area includes: a natural gas dehydration and mercury removal skid, a natural gas deacidification skid, an MR low-pressure compressor skid, an MR high-pressure compressor skid, a cold box, an MR buffer tank, a fuel gas tank, and a manifold skid; the equipment in the public auxiliary area includes: a booster switch skid, a DCS cabinet room, a high-pressure switch skid, a low-pressure switch skid, an air-nitrogen compression skid, an instrument air storage tank, a cooling water circulating pump skid, a cooling tower, a demineralized water skid, and a DCS control room; the loading area... The equipment in the vehicle area includes: LNG loading skids and LNG tank trucks; the auxiliary area and loading area are located on both sides of the drilling platform after entering through the gate. The equipment in the auxiliary area is arranged along the side of the drilling platform towards the far end. The loading area is located near the near end of the drilling platform. The main process area is located on the far inner side of the drilling platform opposite the gate. The wellhead area and loading area are on the same side, and the wellhead area is located between the main process area and the loading area. The natural gas wellhead is located in the middle of the drilling platform. The gas production tree is installed on the natural gas wellhead. The natural gas dehydration and mercury removal skids and natural gas deacidification skids in the main process area are close to the wellhead area. The cold box in the main process area is located on the side where the loading area is located. The MR low-pressure compressor skids and MR high-pressure compressor skids in the main process area are close to the power distribution skids in the auxiliary area. The boost power distribution skids, DCS cabinet room, high-pressure power distribution skids, and low-pressure power distribution skids in the auxiliary area are located near the far end of the drilling platform.

[0005] Furthermore, in the aforementioned natural gas wellhead LNG station, the auxiliary area is also equipped with a gas generator and a diesel generator. The gas generator is powered by a fuel tank, which is supplied with regenerated gas from the natural gas dehydration and mercury removal skid. The diesel generator is used for emergency power generation backup at the station.

[0006] Furthermore, in the aforementioned natural gas wellhead LNG station, a waste heat recovery device is also installed in the auxiliary area. The waste heat recovery device uses the high-temperature flue gas generated by the gas generator to heat the heat transfer oil, providing a heat source for the process skids in the station.

[0007] Furthermore, in the aforementioned natural gas wellhead LNG station, the LNG loading skid in the loading area is equipped with three loading arms, two of which switch between each other for LNG loading, and the other serves as a backup.

[0008] Furthermore, in the aforementioned natural gas wellhead LNG station, the station is equipped with two wastewater tanks. One wastewater tank is used for production, and the wastewater in the other tank is used for loading onto trucks. The wastewater tank is located near the loading area, and the wastewater is loaded onto trucks using the station's existing nitrogen pressurization method, which pressurizes the wastewater into the wastewater tank trucks.

[0009] Furthermore, the aforementioned natural gas wellhead LNG station also includes a fire pump room, fire water tank, and fire truck turnaround area. The fire truck turnaround area is no less than 18 meters × 18 meters and is located between the wellhead area and the main process area, close to the power distribution skid of the auxiliary area.

[0010] Furthermore, in the aforementioned natural gas wellhead LNG station, the booster switchgear and DCS cabinet room, as well as the high-voltage switchgear and low-voltage switchgear in the auxiliary area, are arranged vertically, with the DCS cabinet room and low-voltage switchgear located on top.

[0011] Furthermore, in the aforementioned natural gas wellhead LNG station, the spacing between the skids and equipment in the wellhead area, main process area, and auxiliary area is controlled between 1.5 meters and 2 meters.

[0012] Furthermore, in the aforementioned natural gas wellhead LNG station, the gatehouse and weighbridge are located near the main gate. Behind the gatehouse and weighbridge is the DCS control room, behind the DCS control room is the fire pump room, behind the fire pump room is the cooling water tower, behind the cooling water tower is the cooling water circulation pump skid, behind the cooling water circulation pump skid is the compressed air and nitrogen skid, behind the compressed air and nitrogen skid is the gas generator, behind the gas generator is the waste heat recovery device, behind the waste heat recovery device is the diesel generator, the waste heat recovery device, the step-up distribution skid and the DCS cabinet are arranged side by side, the diesel generator, the high-voltage distribution skid and the low-voltage distribution skid are arranged side by side, the compressed air and nitrogen skid and the instrument air storage tank are arranged side by side, the demineralized water skid and the fire pump room are arranged side by side, and the fire water tank, the DCS control room and the gatehouse and weighbridge are arranged side by side.

[0013] The advantages of this utility model are as follows: the layout of the natural gas wellhead LNG station is compact and reasonable, making full use of the hardened concrete ground of the drilling platform, reducing the amount of site construction, and allowing the drilling platform to be reduced to 100 meters × 60 meters; it mainly adopts a skid-mounted layout, with equipment designed as skids and manufactured in the workshop, which can be flexibly transported to the site for assembly and placement, reducing the amount of on-site installation work and construction costs; the equipment is reasonably arranged according to functional blocks, reducing the amount of materials used for pipelines, steel structures, and instrumentation cables; the process is optimized to make full use of station resources and reduce energy consumption; and the layout fully considers safety requirements. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the natural gas wellhead LNG station described in this utility model.

[0015] Figure 2 This is a schematic diagram of the plan structure of the natural gas wellhead LNG station according to this utility model. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0017] like Figure 1 , Figure 2 As shown, the natural gas wellhead LNG station includes: a drilling platform, which is enclosed by a fence, with a gate 30 at the near end of the drilling platform. The drilling platform is divided into a wellhead area 52, a main process area 53, an auxiliary area 54, and a loading area 55. The equipment in these four areas is interconnected via pipe corridors 31. The equipment in the wellhead area 52 includes: a gas production tree 1, a high-pressure desander 2, a water jacket furnace heating, separation, and metering skid 3, and a wastewater tank 12. The equipment in the main process area 53 includes: a natural gas dehydration and mercury removal skid 4, a natural gas deacidification skid 5, an MR low-pressure compressor skid 6, an MR high-pressure compressor skid 7, a cold box 8, an MR buffer tank 9, a fuel gas tank 10, and a manifold skid 15. The equipment in the auxiliary area 54 includes: a step-up power distribution skid 51, a DCS cabinet room 16, a high-pressure power distribution skid 50, a low-pressure... The equipment in the power distribution skid 17, compressed nitrogen skid 19, instrument air storage tank 20, cooling water circulating pump skid 21, cooling water tower 22, demineralized water skid 25, and DCS control room 26 are as follows: The equipment in the loading area 55 includes: LNG loading skid 11 and LNG tank truck 35; the auxiliary area 54 and loading area 55 are respectively located on both sides of the drilling platform after entering through the gate 30. The equipment in the auxiliary area 54 is arranged along the side of the drilling platform towards the far end. The loading area 55 is located near the near end of the drilling platform. The main process area 53 is located on the far inner side of the drilling platform opposite the gate 30. The wellhead area 52 and loading area 55 are on the same side, and the wellhead area 52 is located between the main process area 53 and loading area 55. The natural gas wellhead is located in the middle of the drilling platform, and the gas production tree 1 is installed on the natural gas wellhead. The natural gas dehydration and mercury removal skid 4 and the natural gas deacidification skid 5 in the main process area 53 are close to the wellhead area 52, reducing the length of the natural gas pipeline from the wellhead to the natural gas dehydration and mercury removal skid 4 and the natural gas deacidification skid 5, thus saving natural gas pipeline materials and construction costs. The cold box 8 in the main process area 53 is located on the side of the loading area 55, reducing the length of the LNG pipeline from the cold box 8 to the loading area 55, thus saving LNG pipeline materials and construction costs. The MR low-pressure compressor skid 6 and the MR high-pressure compressor skid 7 in the main process area 53 are close to the power distribution skid in the auxiliary area 54, reducing the length of the high-voltage cable from the power supply unit to the MR low-pressure compressor skid 6 and the MR high-pressure compressor skid 7, thus saving high-voltage cable materials and construction costs. The step-up power distribution skid 51, the DCS cabinet room 16, the high-voltage power distribution skid 50, and the low-voltage power distribution skid 17 in the auxiliary area 54 are located near the far end of the drilling platform.

[0018] The auxiliary area 54 is also equipped with a gas generator 13 and a diesel generator 18. The gas generator 13 is powered by fuel tank 10, which in turn is powered by regenerated gas from the natural gas dehydration and mercury removal skid 4. The diesel generator 18 is used for emergency power generation in the station. The station's auxiliary area has four gas generators 13. The use of gas generators 13 can adapt to the problem of remote wells without power grids or with power grids but unstable power supply voltage, avoiding production disruptions due to power grid issues. At the same time, it utilizes the existing fuel gas in the station for internal power generation, which is low-cost and provides a stable power supply.

[0019] The auxiliary area 54 is also equipped with a waste heat recovery device 14. The waste heat recovery device 14 uses the high-temperature flue gas generated by the gas generator 13 to heat the heat transfer oil and provide a heat source for the process skids in the station. This changes the traditional process of heating the heat transfer oil furnace with fuel gas. It effectively recovers the heat generated by the gas generator 13, saves energy, eliminates the need for fuel gas to heat the heat transfer oil, and avoids the safety distance problem caused by heating the heat transfer oil with gas.

[0020] The entire process system of the station adopts water cooling, which is more effective than air cooling, especially in areas with high temperatures throughout the year. Air cooling cannot meet the cooling requirements and cannot meet the station's full production needs.

[0021] The regenerated gas cooler in the natural gas dehydration and mercury removal skid 4, the regenerated tower top cooler and lean amine liquid cooler in the natural gas deacidification skid 5, and the refrigerant and oil cooling in the MR low-pressure compressor skid 6 and the MR high-pressure compressor skid 7 all adopt shell-and-tube heat exchanger water cooling. Cooling water circulation pump skid 21 and cooling water tower 22 are provided as cooling water sources in the station's auxiliary areas.

[0022] LNG loading skid 11 in loading area 55 is equipped with three loading arms, two of which are used interchangeably for LNG loading, with the third serving as a backup. This prevents loading arm failures from affecting production. The loading area is located at entrance 30 of the station gate, facilitating the entry and exit of LNG tank trucks for LNG transportation. The weighbridge is located on the road outside the station, near entrance 30 of the station gate, for convenient weighing of LNG tank trucks entering and exiting.

[0023] The station has two wastewater tanks (12). One tank is used for production, and the wastewater in the other is used for loading. The wastewater tank (12) is located near the loading area (55). Wastewater loading utilizes the station's existing nitrogen-pressurized liquid method, pumping the wastewater into the tank trucks without requiring a separate loading pump. The natural gas from the normal gas production tree has a relatively high water content; using two wastewater tanks (12) effectively collects the large amount of wastewater generated at the station, preventing unit shutdowns due to delayed arrival of wastewater tank trucks. The location of the wastewater tanks (12) near the loading area facilitates convenient transportation of wastewater by tank trucks.

[0024] The station is also equipped with a fire pump room 23 and a fire water tank 24 to provide fire water for fire fighting in the event of a fire. It is also equipped with a fire truck turnaround area 33, which allows fire trucks from outside the station to enter and exit the LNG station smoothly, meeting the station's fire safety requirements. The fire truck turnaround area 33 has an area of ​​not less than 18 meters × 18 meters. The fire truck turnaround area 33 is located between the wellhead area 52 and the main process area 53, and is close to the power distribution skid of the auxiliary area 54.

[0025] In the auxiliary area 54, the step-up distribution skid 51 and DCS cabinet room 16, the high-voltage distribution skid 50 and the low-voltage distribution skid 17 are all arranged vertically, with the DCS cabinet room 16 and the low-voltage distribution skid 17 located on the top, which can effectively reduce the land area of ​​the station.

[0026] The spacing between skids and equipment in wellhead area 52, main process area 53, and auxiliary area 54 is controlled between 1.5 meters and 2 meters. This avoids mutual interference between skids and equipment, meets the requirements for personnel inspection passages, and also controls the station area.

[0027] The gatehouse and weighbridge room 27 is located near the main gate 30. Behind the gatehouse and weighbridge room 27 is the DCS control room 26. Behind the DCS control room 26 is the fire pump room 23. Behind the fire pump room 23 is the cooling water tower 22. Behind the cooling water tower 22 is the cooling water circulation pump skid 21. Behind the cooling water circulation pump skid 21 is the compressed air and nitrogen skid 19. Behind the compressed air and nitrogen skid 19 is the gas generator 13. Behind the gas generator 13 is the waste heat recovery device 14. Behind the waste heat recovery device 14 is the diesel generator 18. The waste heat recovery device 14, the step-up distribution skid 51, and the DCS cabinet room 16 are arranged side by side. The diesel generator 18, the high-voltage distribution skid 50, and the low-voltage distribution skid 17 are arranged side by side. The compressed nitrogen skid 19 and the instrument air storage tank 20 are arranged side by side. The demineralized water skid 25 and the fire pump room 23 are arranged side by side. The fire water tank 24, the DCS control room 26, and the gatehouse and weighbridge room 27 are arranged side by side. This arrangement makes the auxiliary area 54 more compact and reasonable.

[0028] The working principle is as follows: Underground natural gas, after being throttled at high pressure at the outlet of the gas production tree 1, enters the high-pressure desander 2 through a pipeline. The high-pressure desander 2 is used to remove solid particles from the produced natural gas. The outlet of the high-pressure desander 2 is connected to the inlet of the water jacket furnace heating, separation, and metering skid 3 through a pipeline. The water jacket furnace heating, separation, and metering skid 3 is used to heat the throttled wellhead natural gas and perform gas-liquid separation and metering. The outlet of the water jacket furnace heating, separation, and metering skid 3 is connected to the inlet of the natural gas filter separator in the natural gas dehydration and mercury removal skid 4 through a pipeline. The natural gas filter separator is used for gas-liquid separation of the feed gas and filtration of solid impurities. The outlet of the natural gas filter separator is connected to the natural gas deacidification skid 5 through a pipeline. The natural gas deacidification skid 5 is used to remove CO from the feed gas. 2Acidic gases such as H2S are removed from the natural gas. The natural gas after deacidification in the natural gas deacidification skid 5 is connected to the molecular sieve and mercury removal bed in the natural gas dehydration and mercury removal skid 4 through a pipeline. The molecular sieve and mercury removal bed are used to remove water and mercury from the raw gas. The natural gas after the mercury removal bed is the purified natural gas. The purified natural gas is connected to the natural gas inlet of cold box 8 via pipeline. The cooling capacity of cold box 8 comes from MR refrigerant supplied by MR low-pressure compressor skid 6 and MR high-pressure compressor skid 7. The MR refrigerant enters cold box 8 and liquefies the natural gas entering cold box 8 through a throttling valve and a stepped cooling process. The MR refrigerant outlet of cold box 8 is connected to MR buffer tank 9 via pipeline. MR buffer tank 9 is used for buffering before entering MR low-pressure compressor skid 6. The outlet of MR buffer tank 9 is connected to MR low-pressure compressor skid 6 via pipeline. MR low-pressure compressor skid 6 is used for the first stage of MR pressurization and cooling. The MR outlet of MR low-pressure compressor skid 6 is connected to the MR inlet of MR high-pressure compressor skid 7 via pipeline. MR high-pressure compressor skid 7 is used for the second stage of MR pressurization and cooling. The MR outlet of MR high-pressure compressor skid 7 is connected to the MR inlet of cold box 8 via pipeline, providing cooling capacity to cold box 8. The liquefied natural gas outlet of cold box 8 enters the throttling valve through pipeline, throttling to approximately 0.2 MPa and -161℃, becoming the product LNG. LNG is supplied via an LNG pipeline to LNG loading skid 11, which is used to fill LNG tank trucks 35 with LNG. Fuel tank 10 provides fuel to gas generator 13. Wastewater tank 12 recovers waste oil and water generated from water jacket furnace heating separation metering skid 3 and natural gas dehydration and mercury removal skid 4. Gas generator 13, step-up distribution skid 51, high-voltage distribution skid 50, low-voltage distribution skid 17, and diesel generator 18 provide power to the station's equipment and facilities. DCS cabinet room 16 and DCS control room 26 house the station's control systems. Waste heat recovery device 14 provides heat to natural gas dehydration and mercury removal skid 4 and natural gas deacidification skid 5. Compressed nitrogen skid 19 and instrument air storage tank 20 provide instrument air and nitrogen to the station. Cooling water circulating pump skid 21 and cooling tower 22 provide cooling water to the station's water-cooling facilities. Demineralized water skid 25 replenishes the amine solution in natural gas deacidification skid 5. Manifold Skid 15 is used to supply refrigerant to MR low-pressure compressor skids and MR high-pressure compressor skids.

Claims

1. Natural gas wellhead LNG terminal, including: The drilling platform, enclosed by a fence, has a gate at its near end. Its features include: a wellhead area, a main process area, an auxiliary area, and a loading area. Equipment in these four areas is interconnected via pipe racks. The wellhead area includes: a gas production tree, a high-pressure desander, a water jacket furnace heating, separation, and metering skid, and a wastewater tank. The main process area includes: a natural gas dehydration and mercury removal skid, a natural gas deacidification skid, an MR low-pressure compressor skid, an MR high-pressure compressor skid, a cold box, an MR buffer tank, fuel gas tanks, and a manifold skid. The auxiliary area includes: a step-up power distribution skid, a DCS cabinet room, a high-voltage power distribution skid, and a low-voltage power distribution skid. The equipment includes: a skid, a compressed nitrogen skid, an instrument air storage tank, a cooling water circulating pump skid, a cooling tower, a demineralized water skid, and a DCS control room; the loading area includes: an LNG loading skid and LNG tank trucks; the auxiliary area and loading area are located on either side of the drilling platform after entering through the main gate. The equipment in the auxiliary area is arranged along the side of the drilling platform towards the far end. The loading area is located near the near end of the drilling platform. The main process area is located on the inner side of the far end of the drilling platform opposite the main gate. The wellhead area and loading area are on the same side, with the wellhead area located between the main process area and the loading area. The natural gas wellhead is located in the middle of the drilling platform, and the gas production tree is installed on the natural gas wellhead. The natural gas dehydration and mercury removal skid and the natural gas deacidification skid in the main process area are close to the wellhead area. The cold box in the main process area is located on the side where the loading area is located. The MR low-pressure compressor skid and the MR high-pressure compressor skid in the main process area are close to the power distribution skid in the auxiliary area. The step-up power distribution skid, DCS cabinet room, high-pressure power distribution skid, and low-pressure power distribution skid in the auxiliary area are located near the far end of the drilling platform.

2. The natural gas wellhead LNG station according to claim 1, characterized in that: The public auxiliary area is also equipped with gas generators and diesel generators. The gas generators are powered by fuel tanks, which are supplied with regenerated gas from the natural gas dehydration and mercury removal skid. The diesel generators are used for emergency power generation in the station.

3. The natural gas wellhead LNG station according to claim 2, characterized in that: The auxiliary area is also equipped with a waste heat recovery device, which uses the high-temperature flue gas generated by the gas generator to heat the heat transfer oil and provide a heat source for the process skids in the station.

4. The natural gas wellhead LNG station according to claim 1, characterized in that: The LNG loading skid in the loading area is equipped with three loading arms, two of which switch between LNG loading and the other as a backup.

5. The natural gas wellhead LNG station according to claim 1, characterized in that: The station is equipped with two sewage tanks. One sewage tank is used for production, and the sewage in the other tank is used for loading. The sewage tank is located near the loading area. The sewage is loaded into the sewage tank cars using the station's existing nitrogen pressurization method.

6. The natural gas wellhead LNG station according to claim 3, characterized in that: The station is also equipped with a fire pump room, fire water tank, and fire turnaround area. The fire turnaround area is no less than 18 meters × 18 meters. The fire turnaround area is located between the wellhead area and the main process area, and close to the power distribution skid of the auxiliary area.

7. The natural gas wellhead LNG station according to claim 1, characterized in that: In the auxiliary area, the step-up power distribution skids and DCS cabinet rooms, as well as the high-voltage power distribution skids and low-voltage power distribution skids, are arranged vertically, with the DCS cabinet rooms and low-voltage power distribution skids located on top.

8. The natural gas wellhead LNG station according to claim 1, characterized in that: The spacing between skids and equipment in the wellhead area, main process area, and auxiliary area should be controlled between 1.5 meters and 2 meters.

9. The natural gas wellhead LNG station according to claim 6, characterized in that: The gatehouse and weighbridge room are located near the main gate. Behind the gatehouse and weighbridge room is the DCS control room, behind the DCS control room is the fire pump room, behind the fire pump room is the cooling water tower, behind the cooling water tower is the cooling water circulation pump skid, behind the cooling water circulation pump skid is the compressed air and nitrogen skid, behind the compressed air and nitrogen skid is the gas generator, behind the gas generator is the waste heat recovery device, and behind the waste heat recovery device is the diesel generator. The waste heat recovery device, the step-up distribution skid, and the DCS cabinet are arranged side by side. The diesel generator, the high-voltage distribution skid, and the low-voltage distribution skid are arranged side by side. The compressed air and nitrogen skid and the instrument air storage tank are arranged side by side. The demineralized water skid and the fire pump room are arranged side by side. The fire water tank, the DCS control room, and the gatehouse and weighbridge room are arranged side by side.

Images