Method for discharging brine from accumulated residues at salt cavity bottoms and communication section of old cavities of butted wells

Abstract

The invention provides a method for discharging brine from accumulated residues at salt cavity bottoms and a communication section of old cavities of butted wells. The method comprises the following steps that (1) water injection well shafts and brine extraction well shafts of the butted wells are transformed correspondingly so as to be used as gas injection wells in a gas injection stage of a gasstorage and as gas extraction wells in a gas extraction stage; (2) a brine discharging well is drilled between the butted wells, so that the brine discharging well is drilled into insoluble residuesin a horizontal communication channel between the butted wells, reaming is carried out on a well hole of an insoluble residue section, and then well cementation construction is carried out; and (3) injection-production strings and a brine discharging string are lowered into the gas injection wells and the brine discharging well respectively according to design requirements, natural gas is injectedinto the gas injection wells, and the brine is discharged from the brine discharging well. The provided method can be used for efficiently utilizing the old cavities of the butted wells through welldrilling water-soluble salt mining, and mainly solves the problem that the brine in the accumulated residues at the salt cavity bottoms and the horizontal communication section is difficult to discharge.

Description

technical field [0001] The invention relates to a method for discharging the brine in the residue accumulated in the bottom of the salt chamber of the old cavity of the well and the connecting section, which belongs to the technical field of natural gas storage, and further belongs to the technical field of the effective utilization of the residue space accumulated at the bottom of the salt cavern gas storage. Background technique [0002] Drilling and water-soluble method of drilling salt is the dominant salt mining method in rock salt deposits in my country at the present stage. The main type of salt mining and dissolution cavity formed in the near future and in the future is the cavity formed by the well. The shape of the cavity formed by the well is complex, and the shape of the salt cavity is usually U-shaped. Most of the salt rock deposits in my country are layered salt rocks, which contain a large amount of insoluble interlayers, and the grade of salt rock in salt mi...

AI Technical Summary

Problems solved by technology

The method involves the efficient use of old well cavity by water-soluble salt mining in drilling, and mainly solves the problem that the brine in the residue accumulated in the bottom of the salt cavity and the horizontal communication section is difficult to discharge

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