Method for increasing production of heavy oil by steam-nitrogen mixed injection and special device

Abstract

The invention relates to the technical field of heavy oil thermal recovery, and particularly relates to a method for increasing production of heavy oil by steam-nitrogen mixed injection and a specialdevice. The method comprises the following steps of: pressurizing and heating high-purity nitrogen, mixing the pressurized and heated high-purity nitrogen with thermal recovery steam to form thermal recovery mixed fluid, and injecting the thermal recovery mixed fluid into a stratum through a steam injection pipeline for heavy oil recovery. Compared with a water injection steam thermal recovery technology, the method has the advantages that: the injected and heated high-purity nitrogen and water steam mixed fluid can carry heat for reducing the viscosity of crude oil, supplement stratum pressure, increase stratum energy and avoid pressure loss caused by volume reduction after water steam is condensed; and the nitrogen can carry the water steam to diffuse in a wider range, so that the oil displacement effect is improved, and the heavy oil recovery cost is reduced.

Description

technical field

[0001] The invention relates to the technical field of thermal recovery of heavy oil, and relates to a production increasing method and a special device for steam and nitrogen mixed injection heavy oil production. Background technique

[0002] Thermal recovery of heavy oil mainly uses the heat carried by thermal fluid to reduce the viscosity of crude oil or ignites crude oil to generate heat to reduce viscosity. Water vapor has the characteristics of large heat capacity, high calorific value, clean and pollution-free, and is widely used in thermal recovery of heavy oil. In the later production process of steam thermal recovery, problems such as difficult recovery, large difference in production degree, increase of heavy components and long drainage period of oil wells have been exposed, which seriously restrict development and production. For deeply buried heavy oil reservoirs, the heat loss is serious during thermal recovery, and the heating radius and swep...

Examples

Embodiment 1

[0026] Embodiment 1: The steam-nitrogen mixed injection method for increasing production of heavy oil production is carried out as follows: utilize nitrogen-making equipment 1 to separate air to obtain high-purity nitrogen and oxygen-enriched air, the purity of high-purity nitrogen is more than 95%, and the high-purity nitrogen After the pressure of pure nitrogen is increased to the same pressure as thermal recovery steam, the pressurized high-purity nitrogen is heated to the same temperature as thermal recovery steam, and the pressurized and heated high-purity nitrogen is mixed with thermal recovery steam to obtain thermal recovery Mixed fluid, the thermal recovery mixed fluid is injected into the formation through the steam injection pipeline for heavy oil recovery.

[0027] The method described in this example mixes high-temperature, high-pressure, high-purity nitrogen with thermal recovery steam and injects it into the formation to maintain the pressure of the steam chamber...

Embodiment 2

[0032] Embodiment 2: As an optimization of Embodiment 1, the thermal recovery steam is produced by the steam injection boiler 2 in the oil field; the oxygen-enriched air is recovered, buffered and pressurized, and then the oxygen-enriched air is sent to the burner 5 of the steam injection boiler 2 in the oil field Moderate combustion, the oxygen content of oxygen-enriched air is in the range of 21% to 99%; the pressurized high-purity nitrogen can be heated to the same temperature as the thermal recovery steam through the oilfield steam injection boiler 2; the thermal recovery steam is saturated steam or superheated steam.

[0033] The production increase method described in this example realizes the generation of high-temperature and high-pressure saturated steam or superheated steam for production increase in heavy oil production, the preparation of high-purity nitrogen, the recovery of oxygen-enriched air, and the heating of nitrogen. 2 The burner 5 burns to make its combust...

Embodiment 3

[0035] Embodiment 3: as attached figure 1 , 2 As shown, the special device for implementing the steam-nitrogen mixed injection method for increasing production of heavy oil includes nitrogen-making equipment 1, nitrogen booster equipment, oxygen-enriched recovery equipment, oil field steam injection boiler 2, nitrogen heating equipment 3 and blender 4, The nitrogen outlet end of the nitrogen making device 1 is connected with the inlet end of the nitrogen booster device, the outlet end of the nitrogen booster device is connected with the inlet end of the nitrogen heating device 3, and the outlet end of the nitrogen heating device 3 is connected with the inlet port of the blender 4. The first inlet port is connected; the mixed gas outlet port of the nitrogen making equipment 1 is connected with the inlet port of the oxygen-enriched recovery device, and the gas outlet port of the oxygen-enriched recovery device is connected with the air inlet port of the burner 5 of the steam inj...

technical field

[0001] The invention relates to the technical field of thermal recovery of heavy oil, and relates to a production increasing method and a special device for steam and nitrogen mixed injection heavy oil production. Background technique

[0002] Thermal recovery of heavy oil mainly uses the heat carried by thermal fluid to reduce the viscosity of crude oil or ignites crude oil to generate heat to reduce viscosity. Water vapor has the characteristics of large heat capacity, high calorific value, clean and pollution-free, and is widely used in thermal recovery of heavy oil. In the later production process of steam thermal recovery, problems such as difficult recovery, large difference in production degree, increase of heavy components and long drainage period of oil wells have been exposed, which seriously restrict development and production. For deeply buried heavy oil reservoirs, the heat loss is serious during thermal recovery, and the heating radius and swep...

Examples

Embodiment 1

[0026] Embodiment 1: The steam-nitrogen mixed injection method for increasing production of heavy oil production is carried out as follows: utilize nitrogen-making equipment 1 to separate air to obtain high-purity nitrogen and oxygen-enriched air, the purity of high-purity nitrogen is more than 95%, and the high-purity nitrogen After the pressure of pure nitrogen is increased to the same pressure as thermal recovery steam, the pressurized high-purity nitrogen is heated to the same temperature as thermal recovery steam, and the pressurized and heated high-purity nitrogen is mixed with thermal recovery steam to obtain thermal recovery Mixed fluid, the thermal recovery mixed fluid is injected into the formation through the steam injection pipeline for heavy oil recovery.

[0027] The method described in this example mixes high-temperature, high-pressure, high-purity nitrogen with thermal recovery steam and injects it into the formation to maintain the pressure of the steam chamber...

Embodiment 2

[0032] Embodiment 2: As an optimization of Embodiment 1, the thermal recovery steam is produced by the steam injection boiler 2 in the oil field; the oxygen-enriched air is recovered, buffered and pressurized, and then the oxygen-enriched air is sent to the burner 5 of the steam injection boiler 2 in the oil field Moderate combustion, the oxygen content of oxygen-enriched air is in the range of 21% to 99%; the pressurized high-purity nitrogen can be heated to the same temperature as the thermal recovery steam through the oilfield steam injection boiler 2; the thermal recovery steam is saturated steam or superheated steam.

[0033] The production increase method described in this example realizes the generation of high-temperature and high-pressure saturated steam or superheated steam for production increase in heavy oil production, the preparation of high-purity nitrogen, the recovery of oxygen-enriched air, and the heating of nitrogen. 2 The burner 5 burns to make its combust...

Embodiment 3

[0035] Embodiment 3: as attached figure 1 , 2 As shown, the special device for implementing the steam-nitrogen mixed injection method for increasing production of heavy oil includes nitrogen-making equipment 1, nitrogen booster equipment, oxygen-enriched recovery equipment, oil field steam injection boiler 2, nitrogen heating equipment 3 and blender 4, The nitrogen outlet end of the nitrogen making device 1 is connected with the inlet end of the nitrogen booster device, the outlet end of the nitrogen booster device is connected with the inlet end of the nitrogen heating device 3, and the outlet end of the nitrogen heating device 3 is connected with the inlet port of the blender 4. The first inlet port is connected; the mixed gas outlet port of the nitrogen making equipment 1 is connected with the inlet port of the oxygen-enriched recovery device, and the gas outlet port of the oxygen-enriched recovery device is connected with the air inlet port of the burner 5 of the steam inj...

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