Gas lift reverse circulation negative pressure sand dredging method and sand dredging device

Abstract

The invention relates to a gas lifting reverse circulation negative pressure sand fishing method and device. The gas lifting reverse circulation negative pressure sand fishing method comprises the following steps that compressed gas is injected into the sand fishing device and expanded in the sand fishing device, the pressure in the sand fishing device forms the negative pressure relative to the pressure in a mineshaft, and setting sand and well liquid in the mineshaft enter the sand fishing device under the effect of the negative pressure, so that sand fishing is achieved. The gas lifting reverse circulation negative pressure sand fishing device comprises a spraying outer pipe and a spraying inner pipe which are concentrically arranged, and the spraying inner pipe, a gas-water mixer and a sand filtering pipe are sequentially arranged in the spraying outer pipe. An annulus space is formed by the outer wall of the spraying inner pipe and the inner wall of the spraying outer pipe. Through holes are formed in the side wall of the spraying outer pipe. The length of the spraying inner pipe is smaller than that of the spraying outer pipe, a sand setting pipe is arranged at the bottom of the spraying outer pipe, and a drill-grinding structure is arranged at the bottom of the sand setting pipe.

Description

technical field [0001] The invention belongs to the field of oil and gas well exploitation, and particularly designs a gas lift reverse circulation negative pressure sand fishing method and a sand fishing device. Background technique [0002] Sand production in oil and gas wells is a common phenomenon in the process of oilfield development, and it is an essential technical measure to restore the normal production of oil and gas wells and remove sand from oil and gas wells. However, when oil and gas wells are producing oil and gas, the cuttings and mud sand in the oil and gas layers will be taken out of the formation and enter the wellbore. With the continuous development of oil and gas production, more and more mud and sand will be accumulated in the downhole to block the oil and gas flow channel of the slotted pipe, and the oil and gas production will become less and less, and the production layer will be buried. And because the pressure in the wellbore is reduced for a lo...

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Problems solved by technology

And because the pressure in the wellbore decreases for a long time, the liquid level drop is no longer located at the wellhead, but leaks in the wellbore, and the sand in the wellbore cannot be brought out of the wellbore by normal circulation.

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