Gap gas lift liquid discharge and gas production control method and system

Abstract

The invention relates to a gap gas lift liquid discharge and gas production control method and system. The sealing height of a pipe opening of a casing pipe is adjusted through a movable sealed piston, and the casing pipe is enabled to descend to the height of a liquid level in a well or below the liquid level; the sealed piston is fixed, an air injection pipe is inserted into a pressure injectioncavity from the sealed piston, and the air injection pipe is fixed to the upper surface and the lower surface of the sealed piston in a penetrating mode through advance insertion; pressure is injected into the pressure injection cavity in the forward direction, so that liquid in the well is discharged out of the well through reverse lifting; the sealed piston is reversely lifted to recover balance of air pressure in the well, and a gas production state is achieved; when the liquid in the well is increased, S100-S400 is repeated to achieve gap gas lift liquid discharge and gas production, themovable gas sealed piston is adopted and used for flexibly adjusting the compression space of the casing pipe, the compression space is not affected by the drilling depth, the starting pressure is greatly reduced, the starting time is shortened, a plurality of gas lift valves are not needed, and the cost is reduced.

Description

technical field [0001] The invention relates to the field of well drilling, in particular to a control method and system for gas production by interstitial gas lift drainage. Background technique [0002] Intermittent gas lift is a main method of liquid drainage for low-yield natural gas wells. By intermittently injecting high-pressure gas from the annular space, it enters the oil pipe through the gas lift valve or the oil pipe foot, so that the liquid accumulated in the wellbore (generally condensate Oil separation or formation water) is brought out from the tubing to restore gas well productivity. Gas lift intermittent time and gas injection time are generally determined by gas production engineers based on experience, and intermittent gas lift control is manually completed by gas production operators. The most core operation step is to take out the fluid accumulated in the wellbore from the tubing, which is commonly done by the completion string at present. [0003] Com...

AI Technical Summary

Problems solved by technology

[0009] (1) This method requires the installation of multiple gas lift valves. Once the gas lift valve fails, it will affect the overall start-up effect and the oil production process, and the gas lift valve is easily polluted in the oil well and causes failure;

[0010] (2) The use of multiple gas lift valves increases the cost,

[0011] (3) The segmented start-up makes the overall start-up time process and the operation complicated, which is not conducive to quick operation and makes the gas production efficiency low

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