Differential pressure type compressor gas lift wellhead pressure reduction device and pressure reduction method applying same

Abstract

The invention discloses a differential pressure type compressor gas lift wellhead pressure reduction device and a pressure reduction method applying the same, and belongs to the technical field of drainage gas recovery matching devices. A pressure reduction device channel of a pressure reduction device separation chamber of the wellhead pressure reduction device communicates with a gas inlet pipe,and a gas-liquid separation channel communicates with a gas outlet pipe; each flow guide unit is used for enabling the pressure reduction channel to communicate with the gas-liquid separation channeland used for carrying out step-by-step pressure reduction along the direction from the gas inlet pipe to the gas outlet pipe; each flow guide units at least comprises two flow guide channels, a slidevalve structure is arranged in the pressure reduction channel and used for pressure relief of the flow guide channels of each flow guide unit; a liquid discharge channel provided with a liquid discharge valve is arranged at the bottom of the gas-liquid separation channel and is used for discharging separated liquid; and the air inlet pipe and the air outlet pipe each are provided with a pressuredetection piece. The invention further discloses the compressor gas lift wellhead pressure reduction method applying the pressure reduction device. The wellhead pressure reduction device guarantees the continuous working duration of a compressor, the liquid drainage efficiency is improved, and the continuity of compressor gas lift measures is guaranteed.

Description

technical field [0001] The invention relates to the technical field of supporting devices for drainage and gas recovery, in particular to a differential pressure compressor gas lift wellhead decompression device and a decompression method thereof. Background technique [0002] Compressor (nitrogen) gas lift needs to discharge the miscible gas-liquid from the bottom of the well to the wellhead downstream of the wellhead. The discharge effect depends on the downstream pressure of the wellhead. During the discharge process, the instantaneous pressure of the wellhead discharge is controlled by adjusting the throttle valve downstream of the wellhead. [0003] According to the national environmental protection requirements, most of the current compressor (nitrogen) gas lift adopts the downstream liquid-draining closed gathering and transportation process. The effect of this process depends on the pressure of the gas-gathering main pipe. The mixed-phase gas-liquid lifted to the we...

AI Technical Summary

Problems solved by technology

Generally, the operating procedures for compressors (gas lift) require wellhead operators to pay attention to the wellhead pressure at all times. Overpressure operation, the valve body and the downstream gas-collecting main pipe will face the danger of damage, and the wellhead operators will also have operational safety risks;

[0006] 2. When the downstream pressure exceeds 5MPa, the wellhead operator adjusts the throttle valve in time. At this time, the liquid discharge speed in the gas collecting main pipe decreases, and part of the mixed-phase gas and liquid lifted to the wellhead will flow back to the bottom of the well, and the compressor (nitrogen) gas It will be difficult to guarantee the lifting and drainage effect, and the effect of a single measure cannot meet the design requirements, and it will also increase the operating cost of the measure

As the gas-liquid mixed phase is discharged from the wellbore, the gas production of the gas well also increases. At this time, a large amount of gas-liquid mixed phase flowing from the main pipe enters the simple separation device of the compressor, and when the gas-liquid mixed phase collected from the gas collecting main pipe is instantaneous Flow over 15m 3 / h and the gas-liquid ratio reaches 0.07m 3 / m 3 At this time, the separation device will not work normally, which will cause the compressor to be overloaded and shut down, which will greatly affect the efficiency of liquid drainage and lifting. At present, there is no better process that can solve the problems encountered by compressor gas lift during the lifting process. this kind of problem

[0010] Although nitrogen can be used as an external gas source to provide lifting energy for fluid effusion recovery wells, the cost of nitrogen compressor gas lift is high and the effect is limited

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