Process method for producing LNG from oilfield associated gas

Abstract

The invention provides a process method for producing LNG from oilfield associated gas. The device is characterized by comprising a feed gas buffer tank, a feed gas compressor, a feed gas cooler and the like. External feed gas enters the feed gas buffer tank through a conveying pipeline; the feed gas buffer tank is respectively connected with a wastewater output boundary pipeline, the feed gas compressor and a stable light hydrocarbon tower through conveying pipelines; the feed gas compressor is connected with a three-phase separation tank through the conveying pipeline, and the feed gas cooler is installed on the conveying pipeline. The process method is suitable for oilfield associated gas, natural gas wellhead gas, natural gas condensate gas and crude oil tank area flash steam. The stable light hydrocarbon tower is additionally arranged and used for removing most heavy hydrocarbons, the influence of the heavy hydrocarbons on a subsequent decarburization and desulfurization system and the molecular sieve dryer is reduced, the problems of oil foaming and molecular sieve poisoning failure of the amine liquid absorption tower are solved, and the loads of the cold box and the refrigeration compressor are reduced.

Description

technical field

[0001] The invention relates to the field of oilfield exploitation, in particular to a process method for producing LNG from oilfield associated gas. Background technique

[0002] In the process of crude oil extraction, relatively light components such as methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane that are usually dissolved in crude oil will be precipitated, called oil field Associated gas is another source of natural gas.

[0003] Because the associated gas is relatively dispersed, it is difficult to recycle and utilize it. Currently, the associated gas recycling technology mainly recovers part of the light hydrocarbons, and the remaining dry gas is used for combustion and venting or power generation. However, there is a vacancy in the technology for liquefying associated gas into LNG, which results in Serious waste of resources.

[0004] After the rapid development of the oil industry in recent years, the governme...

Examples

Embodiment 1

[0026]The invention provides a process for producing LNG from associated gas in an oilfield, which includes a raw material gas buffer tank, a raw material gas compressor, a raw material gas cooler, a three-phase separation tank, a stabilized light hydrocarbon tower, a stabilized light hydrocarbon tower reboiler, decarbonization and desulfurization System, molecular sieve dryer, mercury removal tank, heavy hydrocarbon tower, reboiler, low temperature gas-liquid separator, heavy hydrocarbon reflux pump, cold box, pre-cooling compressor unit, pre-cooling compressor unit condenser, main cooling compressor unit, main The condenser of the cold compressor unit, the external raw material gas enters the raw material gas buffer tank through the delivery pipeline, and the raw material gas buffer tank is respectively connected with the waste water output pipeline, the raw material gas compressor, and the stable light hydrocarbon tower through the delivery pipeline, and the raw material gas ...

Embodiment 2

[0028] Oilfield associated gas production LNG process method of the present invention, its concrete use method is:

[0029] The raw material gas is pressurized to 40-50 bar through the three-stage booster unit, cooled to 45°C by the air cooler, then cooled to 15-20°C by the pre-cooling heat exchanger, and then separated by the three-phase separator, and the gas phase enters the gas phase In the processing unit, the oil phase enters the stable light hydrocarbon tower, and a reboiler is installed at the bottom of the tower. The heat transfer oil or steam is used as the heat source, and the temperature is controlled at 100 ° C ~ 140 ° C. Through heating, the light components are evaporated from the top of the tower and enter the raw material The gas tank, the water phase enters the sewage tank; the gas phase entering from the three-phase separator passes through the decarbonization and desulfurization system, the molecular sieve dryer, and the mercury removal tank in turn; the tre...

technical field

[0001] The invention relates to the field of oilfield exploitation, in particular to a process method for producing LNG from oilfield associated gas. Background technique

[0002] In the process of crude oil extraction, relatively light components such as methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane that are usually dissolved in crude oil will be precipitated, called oil field Associated gas is another source of natural gas.

[0003] Because the associated gas is relatively dispersed, it is difficult to recycle and utilize it. Currently, the associated gas recycling technology mainly recovers part of the light hydrocarbons, and the remaining dry gas is used for combustion and venting or power generation. However, there is a vacancy in the technology for liquefying associated gas into LNG, which results in Serious waste of resources.

[0004] After the rapid development of the oil industry in recent years, the governme...

Examples

Embodiment 1

[0026]The invention provides a process for producing LNG from associated gas in an oilfield, which includes a raw material gas buffer tank, a raw material gas compressor, a raw material gas cooler, a three-phase separation tank, a stabilized light hydrocarbon tower, a stabilized light hydrocarbon tower reboiler, decarbonization and desulfurization System, molecular sieve dryer, mercury removal tank, heavy hydrocarbon tower, reboiler, low temperature gas-liquid separator, heavy hydrocarbon reflux pump, cold box, pre-cooling compressor unit, pre-cooling compressor unit condenser, main cooling compressor unit, main The condenser of the cold compressor unit, the external raw material gas enters the raw material gas buffer tank through the delivery pipeline, and the raw material gas buffer tank is respectively connected with the waste water output pipeline, the raw material gas compressor, and the stable light hydrocarbon tower through the delivery pipeline, and the raw material gas ...

Embodiment 2

[0028] Oilfield associated gas production LNG process method of the present invention, its concrete use method is:

[0029] The raw material gas is pressurized to 40-50 bar through the three-stage booster unit, cooled to 45°C by the air cooler, then cooled to 15-20°C by the pre-cooling heat exchanger, and then separated by the three-phase separator, and the gas phase enters the gas phase In the processing unit, the oil phase enters the stable light hydrocarbon tower, and a reboiler is installed at the bottom of the tower. The heat transfer oil or steam is used as the heat source, and the temperature is controlled at 100 ° C ~ 140 ° C. Through heating, the light components are evaporated from the top of the tower and enter the raw material The gas tank, the water phase enters the sewage tank; the gas phase entering from the three-phase separator passes through the decarbonization and desulfurization system, the molecular sieve dryer, and the mercury removal tank in turn; the tre...

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