CCUS (carbon capture utilization and storage) system for exploiting thickened oil reservoirs based on optimal flue gas CO2 enrichment ratio and working method thereof

Patent metadata

Field	Value
Publication number	US-11208872-B2
Application number	US-201816331929-A
Country	US
Kind code	B2
Filing date	Aug 3, 2018
Priority date	Sep 25, 2017
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A CCUS system for exploiting a thickened oil reservoir based on an optimal flue gas CO2 enrichment ratio. The CCUS system comprises a flue gas CO2 enrichment unit, a flue gas injection unit, a thickened oil thermal production well group unit and a produced gas recovery unit; the fuel gas CO2 enrichment unit comprises an air separating enrichment unit and a boiler injection gas premixed tank; the air separating enrichment unit comprises an air separating primary device used for separating air into oxygen and nitrogen preliminarily, and an air separating secondary device used for further enriching a part of the oxygen which is subjected to the preliminary separation; and the boiler injection gas premixed tank is used for mixing the preliminarily separated nitrogen, the preliminarily separated part of the oxygen and/or the further enriched oxygen.

First claim

What is claimed is:

1. A CCUS (Carbon Capture Utilization & Storage) system for exploiting a thickened oil reservoir based on an optimal flue gas CO 2 enrichment ratio, characterized by comprising a flue gas CO 2 enrichment unit, a flue gas injection unit, a thickened oil thermal production well group unit and a produced gas recovery unit;
the flue gas CO 2 enrichment unit comprises an air separating enrichment unit and a boiler injection gas premixed tank;
the flue gas injection unit comprises a boiler connected with the boiler injection gas premixed tank through a boiler injection gas pressure stabilizer; and a flue gas outlet of the boiler is connected with a flue gas monitoring tank through a boiler flue gas conveying pipeline;
the air separating enrichment unit comprises an air separating primary device used for separating air into oxygen and nitrogen preliminarily; and
an air separating secondary device used for further enriching a part of the oxygen which is subjected to the preliminary separation; and
the boiler injection gas premixed tank is used for mixing the preliminarily separated nitrogen, the preliminarily separated part of the oxygen and/or the further enriched oxygen;
wherein the air separating primary device comprises an air film separating primary device, a nitrogen-rich conveying pipeline, a first oxygen-rich conveying pipeline; a nitrogen-rich air conveying pipeline is connected with a nitrogen-rich gas pressurization monitoring tank; and a first oxygen-rich air conveying pipeline is connected with an oxygen-rich gas pressurization monitoring tank through a second oxygen-rich air conveying pipeline.

2. The CCUS system for exploiting a thickened oil reservoir based on the optimal flue gas CO 2 enrichment ratio of claim 1 , wherein the air separating secondary device comprises an air film separating secondary device; and the first oxygen-rich air conveying pipeline is connected with the oxygen-rich gas pressurization monitoring tank through a third oxygen-rich air conveying pipeline and the air film separating secondary device.

3. The CCUS system for exploiting a thickened oil reservoir based on the optimal flue gas CO 2 enrichment ratio of claim 1 , wherein the boiler flue gas conveying pipeline is provided with a flue gas dust remover, a flue gas dehumidifier, a flue gas desulfurization and denitrification device and a flue gas compressor.

4. The CCUS system for exploiting a thickened oil reservoir based on the optimal flue gas CO 2 enrichment ratio of claim 1 , wherein the thickened oil thermal production well group unit comprises a thermal production well group; the flue gas monitoring tank is connected with the thermal production well group through a thermal production well mouth injection device; and the boiler is connected with the thermal production well mouth injection device through a steam conveying pipeline.

5. The CCUS system for exploiting a thickened oil reservoir based on the optimal flue gas CO 2 enrichment ratio of claim 1 , wherein the produced gas recovery unit comprises a gas-liquid separation device connected with the thermal production well group; the gas-liquid separation device is also connected with a produced gas pressurization monitoring tank through a produced gas conveying pipeline; and the produced gas pressurization monitoring tank is connected with the boiler injection gas premixed tank.

6. The CCUS system for exploiting a thickened oil reservoir based on the optimal flue gas CO 2 enrichment ratio of claim 5 , wherein the produced gas conveying pipeline is provided with a produced gas purification device.

7. A working method of the CCUS system of claim 1 , characterized by comprising steps below:
1) nitrogen and oxygen separation of air and premixing according to a needed proportion comprising:
when the oxygen concentration needed by the boiler is within 20% to 60%, only putting an air film primary device into use; performing primary separation on nitrogen and oxygen in the air by utilizing the air film separating primary device; conveying the nitrogen-rich gas after the separation to the nitrogen-rich gas pressurization monitoring tank through the nitrogen-rich air conveying pipeline; conveying the oxygen-rich gas after the separation to the oxygen-rich gas pressurization monitoring tank through the first oxygen-rich air conveying pipeline and the second oxygen-rich air conveying pipeline; arranging a first gas component monitoring module used for monitoring a nitrogen proportion at the nitrogen-rich gas pressurization monitoring tank and arranging a second gas component monitoring module used for monitoring an oxygen proportion at the oxygen-rich gas pressurization monitoring tank; adjusting a first gas mass flow meter and a second gas mass flow meter to separately control the flow of the nitrogen and that of the oxygen entering in the boiler injection gas premixed tank according to the needed oxygen concentration, and further checking whether the oxygen concentration of the boiler injection gas is at the needed concentration by a third gas component monitoring module;
2) pressure adjustment of nitrogen and oxygen after premixing, injection, and combustion in the boiler comprising:
stabilizing the boiler injection gas pressure by utilizing the boiler injection gas pressure stabilizer, conveying a nitrogen and oxygen premixed gas to a boiler hearth for combustion through the boiler injection gas conveying pipeline after the pressure needed by combustion in the boiler hearth is guaranteed;
3) monitoring, concentration adjustment, and injection-production of the flue gas comprising:
enabling the flue gas caused by boiler combustion to enter a flue gas dust remover, a flue gas dehumidifier and a flue gas desulfurization and denitrification device through a boiler conveying pipeline; enabling the purified flue gas to enter the flue gas monitoring tank through a flue gas compressor; monitoring the flue gas CO 2 enrichment ratio in the flue gas monitoring tank in real-time by a flue gas component monitoring module;
if the flue gas CO 2 enrichment ratio meets the optimal flue gas CO 2 enrichment ratio, opening a first electromagnetic valve, and enabling the flue gas into a thermal production well group through a thermal production well mouth injection device for auxiliary oil production; and
if the flue gas CO 2 enrichment ratio does not meet the optimal flue gas CO 2 enrichment ratio, closing the first electromagnetic valve and opening a second electromagnetic valve, injecting the flue gas back into the boiler injection gas premixed tank, adjusting the flue gas CO 2 concentration by enabling the flue gas to participate in the secondary combustion of the boiler, and enabling the flue gas to enter the flue gas monitoring tank again for secondary analysis;
4) monitoring of produced liquid of the thermal production well group comprising:
conveying steam produced by the boiler to the thermal production well mouth injection device through the steam conveying pipeline and injecting the steam into the thermal production well group for thickened oil thermal production; performing gas-liquid separation on the produced liquid by the gas-liquid separation device in the thermal production process of the thermal production well group; enabling the obtained produced liquid to enter an oilfield manifold for oil-liquid separation; enabling the obtained produced gas to enter the produced gas purification device through the produced gas conveying pipeline to realize dehumidification and purification of the produced gas; enabling the produced gas after the purification to enter the produced gas pressurization monitoring tank, and monitoring the produced gas components by the produced gas component monitoring modules.

Assignees

• Univ China Petroleum

Inventors

• Zhang Chao
• Li Zhaomin
• Liu Jianlin
• Zhao Dongya
• Lu Teng
• Wu Shouya
• Guo Longjiang

Classifications

• E21B43/164

  Injecting CO2 or carbonated water (in combination with organic material C09K8/594) · CPC title

• E21B43/2408

  SAGD in combination with other methods · CPC title

• E21B41/0064 Primary

  Carbon dioxide sequestration (storing fluids in porous layers B65G5/005) · CPC title

• E21B43/40

  Separation associated with re-injection of separated materials {(E21B43/385 takes precedence)} · CPC title

• Y02C20/40

  of CO2 · CPC title