Injection device for discharging accumulated fluids in shaft

Abstract

The invention discloses an injection device for discharging accumulated fluids in a shaft. The injection device comprises a main shaft body with a suction chamber. A three-way pipe and a gas inlet nozzle which are inserted in the suction chamber are arranged at the bottom of the main shaft body, a plurality of sealing grooves are arranged on the periphery of the main shaft body, and each of the sealing grooves is provided with a sealing ring. High-speed jet flows are produced by high-pressure gas at an outlet of the air inlet nozzle, so that a certain vacuum degree is produced in the suction chamber, the accumulated fluids at the shaft bottom are drawn to the suction chamber under the action of inside and outside differential pressure and atomized for a certain degree in the suction chamber, flow into the throat and are fully mixed to form stable gas-liquid two-phase flow. In the process, the high-speed jet flows can transmit part of kinetic energy to the accumulated fluids, the fluid production kinetic energy is increased, and the accumulated fluids are lifted to a shaft head through a pressure diffusion section. Accordingly, the return pressure at the shaft bottom is reduced, the production differential pressure is increased, and the yield of a gas well is increased; and the high-pressure gas in the shaft is expanded due to the reduction of pressure, the instantaneous gas volume is increased, the fluid carrying capacity of the gas hole is further improved, and the accumulated fluids in the shaft are discharged.

Description

technical field [0001] The invention belongs to the technical field of multiphase flow, relates to the technical field of energy saving, and in particular relates to an ejector device for removing wellbore effusion. Background technique [0002] In the process of natural gas production, as the production time continues, the bottom hole pressure of the gas well and the natural gas flow rate gradually decrease, so that the produced water or condensate in the gas reservoir cannot be carried out of the wellbore with the natural gas flow, and thus remain in the wellbore . These liquids accumulate at the bottom of the well for a period of time, forming a liquid column, causing additional hydrostatic back pressure on the gas reservoir, resulting in a continuous decline in the self-flowing energy of the gas well. Typically, if this situation persists, the accumulated fluid column in the wellbore eventually kills the gas, shutting down the well. This phenomenon is called "fluid acc...

AI Technical Summary

Problems solved by technology

However, in practical application of these processes, there are disadvantages such as strict scope of application, high cost, difficult operation, and difficult maintenance.

Adopting conventional drainage gas recovery methods, such as foam drainage gas recovery technology, has many advantages, but it needs to add foam drainage agent to the wellbore regularly and quantitatively. The liquid drainage capacity of the process is not high, and a large amount of foam drainage agent is invested. It also increases the cost of gas production and shortens the economically recoverable life of the gas well

However, the new technology of drainage and gas recovery, such as the ball plug gas lift process, has strong adaptability to low-pressure and low-production wells, and can adapt to complex oil and gas well conditions such as high gas-liquid ratio, sand production, high corrosion, and deep wells; Process adjustment, easy to realize automatic management and adapt to changes in formation productivity; easy to inject chemical agents, good for corrosion and scale prevention, etc., but because the plunger falls in the liquid by its own gravity, the plunger descends slowly, and the discharge volume Relatively limited, and can not achieve continuous gas lift

Coiled tubing drainage gas recovery technology has high construction costs, and the construction is a single operation, which cannot be effective for a long time

At the same time, most of the current drainage gas recovery process equipment needs to be lowered later, such as electric submersible pumps, plungers, capillary tubes, and mechanical pumping. To cause pollution to the formation, the operation of replacing the pipe string is not only expensive, but also delays the normal production cycle of the gas well

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