CN-121976778-A - Salt cavern gas storage brine discharging method, salt cavern gas storage and compressed air energy storage system

CN121976778ACN 121976778 ACN121976778 ACN 121976778ACN-121976778-A

Abstract

The invention relates to the technical field of energy storage, in particular to a salt cavern gas storage brine discharging method, a salt cavern gas storage and a compressed air energy storage system. The brine discharging method of the salt cavern gas storage comprises the following steps of injecting compressed air into the salt cavern gas storage through a gas injection well, simultaneously starting a brine discharging well to discharge brine, and forming a gas cavity in the salt cavern gas storage. And stopping injecting compressed air into the gas injection well, injecting fuel oil into the gas cavity through the gas injection well, igniting the fuel oil by using an igniter arranged at the bottom of the gas injection well, heating the compressed air in the gas cavity to form high-temperature high-pressure gas, and discharging brine from the brine discharge well by using the thermal driving pressure of the high-temperature high-pressure gas. And (5) alternately executing the step S1 and the step S2, and continuously pushing brine in the salt cavern gas storage to be discharged. And when the brine is emptied, carrying out pressurized operation on the oil injection well and the brine discharge well, taking out the central tube and the igniter in the oil injection well, and finishing the transformation of the oil injection well and the brine discharge well. The brine discharge method of the salt cavern gas storage can reduce brine discharge energy consumption and improve brine discharge efficiency.

Inventors

CHEN SHIQING
ZHOU XUEZHI
LI WEN
ZHANG XINJING
Zhu Dielin
XU YUJIE
CHEN HAISHENG

Assignees

中国科学院工程热物理研究所

Dates

Publication Date: 20260505
Application Date: 20260228

Claims (10)

1. The brine discharge method for the salt cavern gas storage is characterized by comprising the following steps of: S1, injecting compressed air into a salt cavern gas storage through a gas injection well, and simultaneously starting a brine discharging well to discharge brine to form a gas cavity in the salt cavern gas storage; s2, stopping injecting compressed air into the gas injection well, injecting fuel oil into the gas cavity through the oil injection well, igniting the fuel oil by using an igniter arranged at the bottom of the oil injection well, heating the compressed air in the gas cavity to form high-temperature high-pressure gas, and discharging brine from the brine discharge well by using the thermal driving pressure of the high-temperature high-pressure gas; s3, alternately executing the step S1 and the step S2, and continuously pushing brine in the salt cavern gas storage to be discharged; and S4, after the brine is emptied, carrying out pressurized operation on the oil injection well and the brine discharge well, taking out the central tube and the igniter in the oil injection well, and finishing the functional transformation of the oil injection well and the brine discharge well.
2. The brine discharge method of salt cavern gas storages according to claim 1, wherein in step S1, compressed air is injected into the salt cavern gas storages through the gas injection well by driving the compressed air storage device with electric energy.
3. The brine discharge method of salt cavern gas storage according to claim 1, wherein in step S2, the density of the fuel is less than the brine density, the injected fuel floats above the liquid surface of the brine, and the fuel can burn in the gas cavity and heat the compressed air after being ignited.
4. A salt cavern gas storage brine discharge method according to claim 3 wherein in step S2 the injected fuel is diesel, gasoline or kerosene.
5. The brine discharge method of salt cavern gas storage according to claim 1, wherein in step S2, the temperature and pressure of the high temperature and high pressure gas are adjusted to linearly increase the thermal driving pressure by controlling the fuel injection amount according to van der waals equation.
6. The brine discharge method of a salt cavern gas storage according to claim 1, wherein in step S4, the oil injection well is modified to be a gas injection well and the brine discharge well is modified to be a gas production well.
7. The salt cavern gas storage brine discharge method according to claim 1, wherein the salt cavern gas storage brine discharge method includes, prior to step S1: Building a gas injection well, a gas injection well and a brine discharge well for the salt cavern gas storage; the central tube is arranged in the oil filling well, the igniter is arranged at the bottom of the central tube, and the brine discharging well extends to the bottom of the salt cavern gas storage in an inclined well drilling mode.
8. A salt cavern gas storage, characterized in that the salt cavern gas storage is formed by a salt cavern gas storage halogen removal method according to any one of claims 1 to 7, the salt cavern gas storage comprising: the salt cavern cavity is formed by water-soluble mining of underground salt rock; the gas injection well is a high-pressure wellhead device and is arranged at the top of the salt cavern cavity and used for injecting compressed air into the salt cavern cavity; The oil injection well is a high-pressure wellhead device and is arranged at the top of the salt cavern cavity, a central pipe is arranged in the oil injection well, a packer and an igniter are arranged at the bottom of the central pipe, the central pipe is used for injecting fuel into the salt cavern cavity, and the igniter is used for igniting the fuel to heat the compressed air in the salt cavern cavity; the lower end of the brine discharging well extends to the bottom of the salt cavern cavity and is used for discharging brine in the salt cavern cavity.
9. The salt cavern gas storage of claim 8, wherein the oil injection well is adapted to be a gas injection well of the salt cavern gas storage after the central tube and the igniter are removed by the pressurized operation, and the brine discharge well is adapted to be a gas production well of the salt cavern gas storage after the pressurized operation.
10.A compressed air energy storage system, characterized by comprising a salt cavern gas storage and a compressed air energy storage device according to claim 8 or 9, wherein the compressed air energy storage device is communicated with the gas injection well of the salt cavern gas storage, and the compressed air energy storage device is used for injecting compressed air into the salt cavern gas storage.

Description

Salt cavern gas storage brine discharging method, salt cavern gas storage and compressed air energy storage system Technical Field The invention relates to the technical field of energy storage, in particular to a salt cavern gas storage brine discharging method, a salt cavern gas storage and a compressed air energy storage system. Background The underground salt cavern has extremely low permeability due to the salt rock, and simultaneously has good creep property and damage recovery capability, and is a preferable carrier of a gas storage device in the compressed air energy storage system. The underground salt cavern formed by water solution exploitation is used as an energy underground reservoir, has extremely high safety, and is widely applied to the field of compressed air energy storage. The salt cavern is required to realize the use function of the gas storage, and brine in the cavity is required to be completely discharged, which is a key pre-working procedure for constructing the salt cavern gas storage. In the related art, the brine discharging method of the salt cavern gas storage mainly comprises the steps of injecting high-pressure air into the salt caverns through an air compressor or a nitrogen compressor, pushing brine to be discharged by means of the pressure of the air, and the problems of high energy consumption and long brine discharging period exist in the mode, so that the construction energy consumption cost of the salt cavern gas storage is greatly increased, the construction progress of the salt cavern gas storage is delayed, and the working efficiency is reduced. Therefore, there is a need to design a salt cavern gas storage brine discharging method, a salt cavern gas storage and a compressed air energy storage system to solve the above technical problems. Disclosure of Invention The invention aims to provide a salt cavern gas storage brine discharge method, a salt cavern gas storage brine discharge and a compressed air energy storage system, which can reduce brine discharge energy consumption, improve brine discharge working efficiency and achieve the aim of saving cost. To achieve the purpose, the invention adopts the following technical scheme: in a first aspect, the invention provides a salt cavern gas storage brine discharge method, comprising the following steps: S1, injecting compressed air into a salt cavern gas storage through a gas injection well, and simultaneously starting a brine discharging well to discharge brine to form a gas cavity in the salt cavern gas storage; s2, stopping injecting compressed air into the gas injection well, injecting fuel oil into the gas cavity through the oil injection well, igniting the fuel oil by using an igniter arranged at the bottom of the oil injection well, heating the compressed air in the gas cavity to form high-temperature high-pressure gas, and discharging brine from the brine discharge well by using the thermal driving pressure of the high-temperature high-pressure gas; s3, alternately executing the step S1 and the step S2, and continuously pushing brine in the salt cavern gas storage to be discharged; and S4, after the brine is emptied, carrying out pressurized operation on the oil injection well and the brine discharge well, taking out the central tube and the igniter in the oil injection well, and finishing the functional transformation of the oil injection well and the brine discharge well. As an alternative technical scheme of the brine discharging method of the salt cavern gas storage, in the step S1, electric energy is utilized to drive a compressed air energy storage device, and compressed air is injected into the salt cavern gas storage through a gas injection well. As an alternative technical scheme of the brine discharging method of the salt cavern gas storage, in the step S2, the density of fuel is smaller than that of brine, injected fuel floats above the brine liquid level, and the fuel can burn in a gas cavity and heat compressed air after being ignited. As an alternative technical scheme of the brine discharging method of the salt cavern gas storage, in the step S2, the injected fuel oil is diesel oil, gasoline or kerosene. As an alternative technical scheme of the salt cavern gas storage brine discharging method, in step S2, the temperature and pressure of high-temperature high-pressure gas are regulated by controlling the fuel injection amount according to a Van der Waals equation so as to enable the thermal driving pressure to linearly increase. As an alternative technical scheme of the brine discharge method of the salt cavern gas storage, in step S4, the oil injection well is modified into a gas injection well, and the brine discharge well is modified into a gas production well. As an alternative technical scheme of the salt cavern gas storage brine discharge method, before step S1, the salt cavern gas storage brine discharge method comprises the following steps: Building a gas injection well, a gas injection