Sand Control String

Abstract

The invention discloses flushing fishers and a sand control string. The sand control string comprises a casing, a plurality of screen tubes located below the casing, the multiple flushing fishers located between the casing and the screen tube at the uppermost end and between the two adjacent screen tubes, and a first wire plug; the starting pressure of the flushing fishers is increased gradually in sequence from top to bottom; the first wire plug is connected to the lower end of the screen tube at the lowermost end; each flushing fisher comprises an upper connector, an inner tube, an outer tube and a sliding mechanism, the upper ends of the inner tubes and the inner sides of the lower ends of the upper connectors are fixed, and the upper ends of the outer tubes and the outer sides of the lower ends of the upper connectors are fixed; and the sliding mechanisms are arranged between the outer tubes and the inner tubes, and when the sliding mechanisms are started under the predetermined pressure, the inner tubes communicate with the outer tubes. According to the flushing fisher and the sand control string, the flushing effect of well flushing fluid to formation sand can be improved, during fishing, the sand control string is not required to be fished in sections, the operation time is reduced, and the operation cost is saved.

Description

technical field [0001] The invention relates to the technical field of downhole operation tools for oil and water wells, in particular to a sand control string. Background technique [0002] In the process of heavy oil production, because the formation is loosely cemented and easy to produce sand, screen sand control is widely used as the most important sand control method. [0003] Please refer to Figure 1A , in the pre-sand control mode of the vertical well of the oil well, the oil layer casing is generally lowered, and after the perforation is connected to the oil layer, the sand control string is run in the casing 1. After a period of production, the annular space between the screen pipe 2 and the perforated casing 3 will be filled with formation sand. Due to the need for post-production operations or replacement of the screen pipe 2, it is often necessary to lift out the sand control string, and the formation sand in the annulus of the screen sleeve makes it very diff...

AI Technical Summary

Problems solved by technology

This method is widely used, but when the well depth is large, the screen pipe 2 is repeatedly lifted up and down, resulting in a long working time and increasing the construction cost

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