Automatic underground sand bailing device and sand bailing process thereof

Abstract

The invention discloses an automatic underground sand bailing device and a sand bailing process thereof. According to the device, a steel wire rope is used for driving a sand bailing pump to move vertically for realizing automatic sand bailing. A rope guide wheel is coaxially provided with an angular displacement sensor for detecting the length of the steel wire rope. A fixed pulley base is provided with a load sensor for detecting the load of the steel wire rope. A sand loosening hammer and a valve plug of a sand inlet valve at the bottom of the sand bailing pump are of an integrated structure. The steel wire rope is connected with a rope ring on the top of a weighted piston rod, so as to drive a piston to move vertically in a walking cavity between the sand inlet valve and a sand carrying valve. When the piston moves downwards, the upper part of the walking cavity forms negative pressure, and sand carrying well fluid on the lower part of the walking cavity pushes to open a check valve in the piston and enters the upper part of the walking cavity. Before the piston touches the bottom dead centre while moving downward, the piston moves downward slowly so as not to impact a bottom dead centre. Before the piston touches the top dead centre while moving upward, the piston moves upward slowly so as not to impact the top dead centre. The automatic underground sand bailing device and the sand bailing process thereof have the advantages that simplicity and reliability are realized, the pump efficiency is high, the degree of automation is high, the piston is effectively prevented from impacting a top dead centre and the bottom dead centre, and the device and the process are particularly suitable for low-liquid level oil-water well sand bailing.

Description

technical field [0001] The invention relates to the technical field of petroleum and natural gas machinery, in particular to an underground sand fishing device and a sand fishing process for solving the problem of sand production in the production process of oil and gas wells. Background technique [0002] During the production process of oil and gas wells, formation sand continuously flows into oil and gas wells from the formation along with liquid, and gradually deposits downhole, causing oil and gas reservoirs to be buried by sand, and downhole and surface equipment to wear, etc., resulting in production reduction or even shutdown of oil and gas wells. [0003] At present, there are generally two methods for sand removal in oil and gas wells: one is to remove sand accumulated in the well by hydraulic sand washing. The sand at the bottom of the well is flushed by injecting high-pressure sand flushing fluid, and the sand is carried out of the well by the sand flushing fluid...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems existing in the existing sand fishing pump, the present invention provides an automatic sand fishing device and its sand fishing process in the well. The invention is simple and reliable, has high degree of automation and high pump efficiency, and can effectively avoid the impact of the piston on the upper and lower dead points , especially suitable for dredging sand in oil and water wells with low liquid level

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