KR102682134B1 - Gas treatment system and Offshore plant having the same - Google Patents

Abstract

A gas processing system according to an embodiment of the present invention includes a gas production unit that processes and liquefies gas produced in a gas well and delivers it to a liquefied gas storage tank; a low-pressure flare drum storing fluid discharged from the gas production unit; and a flare tower that receives and burns the gas separated from the low-pressure flare drum, wherein the low-pressure flare drum stores the drain generated in the gas production unit, so that the drain drum is omitted.

Description

Gas treatment system and offshore structure including the same {Gas treatment system and Offshore plant having the same}

The present invention relates to gas processing systems and marine structures comprising the same.

As environmental regulations have recently been strengthened, the use of natural gas, which is close to eco-friendly fuel, is increasing among various fuels. Natural gas can be extracted in a gaseous state from gas wells located in inland or marine formations. The extracted natural gas undergoes pretreatment such as mercury removal, drying, and NGL removal, and then undergoes a liquefaction process for storage and transportation. It can be liquefied through

Natural gas can change into a liquid state by being cooled below its boiling point (for example, -162°C under 1 atmosphere) while exchanging heat with a refrigerant. When it becomes a liquid, its volume is reduced to 1/600 compared to the gaseous state, so it can be stored and stored as a liquid. Transport efficiency can be increased.

The above liquefaction process can be carried out in a plant on land or FLNG at sea, and the liquefied natural gas can be stored in an LNG storage tank and then supplied to consumers.

For example, natural gas can be supplied from an LNG storage tank to a city gas facility or power generation facility on land, or it can be delivered to the cargo tank of an LNG carrier and transported to a desired area by the LNG carrier.

At this time, natural gas may be vaporized and consumed after being discharged from an LNG storage tank or cargo tank, and vaporization facilities may be provided in land plants, FLNG, etc., or in facilities that consume natural gas.

In this way, after natural gas is extracted from a gas well, it is consumed by sequentially going through pretreatment, liquefaction, storage, transportation, and vaporization processes. Various research and development are being conducted to ensure the stability and improve efficiency of gas production, processing, and supply. This is being done continuously.

The present invention was created to improve the prior art, and the purpose of the present invention is to provide a gas processing system capable of a compact structure to increase the utilization of limited space within the marine structure and an marine structure including the same.

A gas processing system according to an embodiment of the present invention includes a gas production unit that processes and liquefies gas produced in a gas well and delivers it to a liquefied gas storage tank; a low-pressure flare drum storing fluid discharged from the gas production unit; and a flare tower that receives and burns the gas separated from the low-pressure flare drum, wherein the low-pressure flare drum stores the drain generated in the gas production unit, so that the drain drum is omitted.

A gas processing system according to another embodiment of the present invention includes a gas production unit that processes and liquefies gas produced in a gas well and delivers it to a liquefied gas storage tank; a low-pressure flare drum storing fluid discharged from the gas production unit; A flare tower that receives and burns the gas separated from the low-pressure flare drum; It includes a drain drum that stores drain generated from the gas production unit, and the low-pressure flare drum is provided integrally with the drain drum to form a single communicating space.

An offshore structure according to another embodiment of the present invention is characterized by including the gas processing system.

Specifically, a pressure sensor (PT) provided in the low-pressure flare drum to measure internal pressure; And it may further include a discharge valve that controls the gas flow rate discharged from the low-pressure flare drum to the flare tower.

Specifically, a flare source line connected to the low-pressure flare drum; And it may further include a drain source line connected to the low-pressure flare drum and spaced apart from the flare source line.

Specifically, a pressure sensor (PT) provided in the low-pressure flare drum to measure internal pressure; And it may further include a discharge valve that controls the gas flow rate discharged from the low-pressure flare drum to the flare tower.

Specifically, a flare source line connected to the low-pressure flare drum; and

It may further include a drain source line connected to the low-pressure flare drum and spaced apart from the flare source line.

The gas processing system and the marine structure including the same according to the present invention can increase space utilization by compacting the structure within the marine structure with a limited space, making equipment installation and design easier, and liquid generated from the low-pressure flare drum. The configuration can be simplified by omitting the pump for transferring to the drain drum.

1 is a diagram illustrating an offshore structure in which a gas processing system according to an embodiment of the present invention is provided.
Figure 2 is a diagram conceptually showing a gas processing system according to an embodiment of the present invention.

The objectives, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In this specification, when adding reference numbers to components in each drawing, it should be noted that identical components are given the same number as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a diagram illustrating an offshore structure equipped with a gas processing system according to an embodiment of the present invention, and FIG. 2 is a diagram conceptually illustrating a gas processing system according to an embodiment of the present invention.

Referring to Figures 1 and 2, an offshore structure (OP) according to an embodiment of the present invention is a facility that receives gas produced from a gas well located on land or in the ocean, processes, refines, liquefies, stores it, and supplies it to the consumer. As such, it may mean offshore plants such as FLNG, FSRU, etc.

Of course, the offshore structure (OP) of the present invention can be used as a concept encompassing general merchant ships as long as it can be equipped with a gas processing configuration.

The offshore structure (OP) includes the hullside (HS), which is the hull, and the topside (TS), which is provided on the hull. The hullside (HS) can mainly provide storage space, and the topside (TS) can store gas. A gas processing system 10 can be provided.

For example, Hullside (HS) may be equipped with a liquefied gas storage tank (GT) and an oil tank (OT).

A liquefied gas storage tank (GT) is a structure that purifies, liquefies, and stores produced gas, and may be provided as a membrane type to stably store gas in a cryogenic liquid state, but is not limited to this.

And just as the oil tank (OT) can store oil that can be used as lubricant, etc., the space provided in Hullside (HS) can be composed of various tanks.

In addition, the topside (TS) includes a gas processing system 10 for processing gas stored in a liquefied gas storage tank (GT), etc.

However, in the case of an oil tank (OT) with a relatively small capacity, the arrangement of the configuration can be varied in various ways, such as being installed on the topside (TS) rather than the hullside (HS), so the arrangement of the tank and equipment, etc. and the design is not limited to the embodiments described herein.

Here, the gas processing system 10 is a component that processes gas and includes a gas production unit 11, a low-pressure flare drum 12, and a flare tower (FT), and can be compactized through this configuration, saving space. Utilization may increase.

First, the gas production unit 11 processes and liquefies the gas produced in the gas well and delivers it to the liquefied gas storage tank (GT).

For example, the gas production unit 11 may include a (pre)processing unit (not shown), a liquefaction unit (not shown), etc., and may (pre)process and liquefy gas through a known mechanism. Briefly, it is as follows.

The (pre)treatment unit may perform pretreatment such as removing mercury from the gas, washing away impurities using water, or removing acidic substances, and may separate the gas from which impurities have been removed through pretreatment.

For example, the (pre) treatment unit includes a heater (not shown), a gas-liquid separator (not shown), a mercury remover (not shown), a pre-washer (not shown), and an amine contactor (not shown) for pretreatment of gas. (not shown), dryer (not shown), etc.

And the (pre-) treatment unit uses a gas-liquid separator (not shown) and an expander (not shown) to separate Natural Gas Liquids (NGL, the main components of which may be butane and pentane) from the gas from which impurities have been removed. (not shown), a compressor (not shown), a precooler (not shown), etc.

Here, the natural gas liquid is a different material from the gas (for example, LNG) that must be produced in the final group, so it can be separated and processed separately. At this time, the separated natural gas liquid is stored in the low-pressure flare drum 12 or stored in the low-pressure flare drum (12). After being stored in 12), it can be burned by the flare tower (FT).

The liquefaction unit can cool the gas using a refrigerant, for example, to liquefy the gas separated from the natural gas liquid by the (pre)processing unit, and includes a compander (not shown) and a gas-liquid separator (not shown). , a liquefaction device (not shown), a refrigerant supplier (not shown), a pressure reducer (not shown), etc.

The impurities/NGL are removed by the gas production unit 11 and the liquefied gas can be finally stored in the liquefied gas storage tank (GT).

The low-pressure flare drum 12 may have a structure in which a space is formed to store the fluid discharged from the gas production unit 11, and may also be provided with a pressure sensor (PT) and a discharge valve (DB).

Here, the low-pressure flare drum 12 is used to lower the pressure for the safety of the system, that is, to prevent dangerous situations caused by high pressure, and as described later, the discharge valve ( The pressure can be lowered by adjusting DB).

In particular, the low-pressure flare drum 12 of this embodiment combines systems with different functions, such as a flare source (requires pressure reduction when forming high pressure) and a drain source (used when repairing equipment), and not only the flare source but also the gas production unit (11). ) If discharge is necessary for equipment repair, etc., that is, the drain generated by the drain of the gas production unit 11 is stored and the drain drum is omitted. For this purpose, the low-pressure flare drum 12 can be integrated with the drain drum.

Alternatively, it may include a drain drum 12A that stores the drain generated in the gas production unit 11, and the low-pressure flare drum 12 may be provided integrally with the drain drum 12A to form a single communicating space.

Accordingly, this embodiment can increase space utilization by compacting the structure within a marine structure with limited space.

In this low-pressure flare drum 12, both a flare source for lowering high pressure and a drain source for equipment maintenance can be linked. In other words, the low-pressure flare drum 12 allows the flare source and drain source to flow separately. The flare source line (L11) and the drain source line (L11A) may be connected, and a flare line (L12) for discharging the flare gas may be connected.

Here, the flare source line (L11) can be connected from the gas production unit 11 to the low-pressure flare drum 12, and the drain source line (L11A) allows fluid drained from each equipment provided in the gas production unit 11 to pass through. For this reason, it can be connected to the low-pressure flare drum (12) separately from the flare source line (L11). And the flare line (L12) is connected from the low-pressure flare drum (12) to the flare tower (FT) to allow gas to pass through.

In addition, the specifications (pressure, temperature, etc.) of the fluid passing through the flare source line (L11) and the drain source line (L11A) may vary depending on the operating state of the gas production unit 11, etc.

For example, the fluid flowing through the flare source line (L11) may be composed of gas introduced by the normal operation of the gas production unit 11, and may have a relatively high pressure compared to the drain source line (L11A), and the pressure sensor Depending on the pressure sensed by (PT), it can be moved from the low pressure flare drum (12) immediately or later to the flare tower (FT).

Alternatively, the fluid flowing in through the flare source line (L11) may be mixed with the fluid flowing in through the drain source line (L11A) and reused through an additional processing process.

In addition, the fluid flowing in through the drain source line (L11A) may be in an emergency state due to various situations in the gas production unit 11, such as when one or more equipment stops operating due to equipment load, etc., or equipment repair is required. Discharge may be required in some cases. In this way, the fluid passing through the drain source line (L11A) can be stored/usable through additional processing, and is simply stored in the low-pressure flare drum 12 or later recovered to the gas production unit 11 for processing. may be made, or may be temporarily stored in the low-pressure flare drum 12 and then discarded.

In this way, the flare source line (L11) and the drain source line (L11A) can be introduced from different driving states of the gas production unit 11, so for example, when equipment is being repaired, the gas production unit 11 is not driven. As the flow of the flare source line (L11) may stop due to a stopped state, the timing of the passage of the fluid may be different, and the flow of the fluid through the drain source line (L11A) may be different due to infrequent equipment repairs. The frequency may be relatively low compared to the flow of fluid through the flare source line (L11).

In addition, since the inflow timing of the fluid flowing through the flare source line (L11) and the drain source line (L11A) is different, the drain source must be drained before the fluid flows into the low-pressure flare drum 12 through the flare source line (L11). Various modifications are possible, such as emptying the inside of the low-pressure flare drum 12 by recycling the fluid in the low-pressure flare drum 12 introduced through the line L11A through recovery or other methods.

In addition, the low-pressure flare drum 12 may temporarily store the stored fluid and later discard the fluid in the low-pressure flare drum 12 on land, etc., so it may not be connected to the dirty slop tank, but it can also be connected to the dirty slop tank. .

For example, when returning the fluid in the low-pressure flare drum 12 to the gas production unit 11, slop (sewage) generated during the gas treatment process is separated. At this time, the sewage can be discharged from the low-pressure flare drum 12 and separated from the reusable fluid.

This is because a detection sensor (not shown, foreign matter concentration detection, etc.) is provided in the low-pressure flare drum 12 to detect sewage, and when the fluid flowing into the low-pressure flare drum 12 or the fluid in the low-pressure flare drum 12 is detected as sewage, A valve (not shown) may be opened to allow discharge.

Here, the slop discharged from the low-pressure flare drum 12 is stored in an existing dirty slop tank (not shown) without the need to store it in a separate configuration for storing sewage discharged from the low-pressure flare drum 12. It can be.

The dirty slop tank is a configuration that stores sewage delivered from Hullside (HS) rather than a separately added configuration, and can store sewage discharged from the low-pressure flare drum 12 downstream of the low-pressure flare drum 12, A line (not shown) and an opening/closing valve (not shown) may be provided to discharge slop from the low pressure flare drum 12 to the dirty slop tank.

And the pressure sensor (PT) provided in the low-pressure flare drum 12 can measure the internal pressure of the low-pressure flare drum 12, as mentioned above, and the discharge valve DB detects the flare from the low-pressure flare drum 12. The gas flow rate discharged to the tower (FT) can be controlled.

Here, when the pressure sensor (PT) detects more than the preset internal pressure of the low pressure flare drum 12, the opening degree of the discharge valve (DB) can be adjusted in conjunction with the internal pressure detected by the pressure sensor (PT), so that the flare tower ( The gas flow rate supplied to the FT) can be controlled.

The flare tower (FT) receives and burns the gas separated from the low-pressure flare drum (12) by adjusting the opening degree of the discharge valve (DB).

For example, the flare tower (FT) can burn the gas discharged to adjust the internal pressure of the low-pressure flare drum 12, and the object burned in the gas combustion for internal pressure adjustment is the fluid processing process of the gas production unit 11. may include gases that are discharged to the outside due to various factors and must be discarded.

Since the operating mechanism of the flare tower (FT) is a known technology, detailed description will be omitted.

In this way, in this embodiment, space utilization can be increased by compacting the structure within the offshore structure (OP) having a limited space, so equipment installation and design can be facilitated, and liquid generated in the low-pressure flare drum 12 can be drained. The configuration can be simplified by omitting the pump for transfer to the drum.

Although the present invention has been described in detail through specific examples, this is for detailed explanation of the present invention, and the present invention is not limited thereto, and can be understood by those skilled in the art within the technical spirit of the present invention. It would be clear that modifications and improvements are possible.

All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be made clear by the appended claims.

OP: Offshore Structures HS: Hullside
TS: Topside GT: Liquefied gas storage tank
FT: Flare tower PT: Pressure sensor
DB: discharge valve 10: gas treatment system
11: Gas production unit L11: Flare source line
L11A: Drain Source Line 12: Low Pressure Flare Drum
12A: Drain drum L12: Flare line

Claims (7)

A gas production department that processes and liquefies gas produced from gas wells and delivers it to a liquefied gas storage tank;
a low-pressure flare drum storing fluid discharged from the gas production unit; and
It includes a flare tower that receives the gas separated from the low-pressure flare drum and burns it to adjust the pressure of the low-pressure flare drum,
The low pressure flare drum,
A gas processing system characterized in that the drain generated from the gas production unit is stored, a drain drum is omitted, and the gas processing system is a closed space so that the pressure varies depending on the fluid and drain stored therein. According to paragraph 1,
A pressure sensor (PT) provided in the low-pressure flare drum to measure internal pressure; and
A gas processing system further comprising a discharge valve that controls a gas flow rate discharged from the low-pressure flare drum to the flare tower. According to paragraph 1,
a flare source line connected to the low-pressure flare drum; and
A gas processing system further comprising a drain source line connected to the low pressure flare drum and spaced apart from the flare source line. A gas production department that processes and liquefies gas produced from gas wells and delivers it to a liquefied gas storage tank;
a low-pressure flare drum storing fluid discharged from the gas production unit;
a flare tower that receives the gas separated from the low-pressure flare drum and burns it to control the pressure of the low-pressure flare drum;
It includes a drain drum that stores drain generated from the gas production unit,
The low pressure flare drum,
A gas processing system characterized in that it is provided as an integrally closed space to form a single communicating space with the drain drum, and the pressures are synchronized with each other. According to paragraph 4,
A pressure sensor (PT) provided in the low-pressure flare drum to measure internal pressure; and
A gas processing system further comprising a discharge valve that controls a gas flow rate discharged from the low-pressure flare drum to the flare tower. According to paragraph 4,
a flare source line connected to the low-pressure flare drum; and
A gas processing system further comprising a drain source line connected to the low-pressure flare drum separately from the flare source line. An offshore structure comprising the gas processing system of any one of claims 1 to 6.