Precise positioning, gravel filling and water stop device for deep well

Abstract

The invention discloses a precise positioning, gravel filling and water stop device for a deep well. The device includes positioning pipes and a gravel throwing device; the outside of the gravel throwing device is sleeved by the positioning pipes, and the positioning pipes are detachably connected with the positioning pipes; multiple first discharge openings are circumferentially and uniformly distributed on the pipe walls of the positioning pipes; the gravel throwing device includes a feeding drill rod, retention pipes and guide apparatuses; the guide apparatuses are fixedly connected with the upper part of the feeding drill rod; the feeding drill rod is movable connected with the retention pipes; the outer sides of the guide apparatuses are sleeved by the positioning pipes, and the outersides of the retention pipes are fixedly sleeved by the positioning pipes; multiple second discharge openings corresponding to the multiple first discharge openings are circumferentially and uniformly distributed on the pipe walls of the retention pipes; and multiple discharge openings are circumferentially and uniformly distributed on the pipe wall of the feeding drill rod. The device overcomesthe defects that gravel is prone to "bridge formation" between a wellbore wall and a well pipe in a conventional deep well gravel filling process, and gravel material filling is not dense enough, so that a gravel throwing position moves down to down-hole, thereby shortening a gravel filling path, and occurrence of a "bridge formation" phenomenon is effectively prevented.

Description

technical field [0001] The invention relates to the technical field of drilling gravel packing tools, in particular to a deep well precisely positioned gravel packing water stop device. Background technique [0002] In the process of gravel throwing and water stop in deep wells, due to the small gap between the drilling hole wall and the well pipe and the irregular hole wall, when gravel is filled from the outside of the well pipe, it is easy to cause the gravel to be trapped between the drilling hole wall and the well pipe. The gravel filling height and water stop position are not accurate, which seriously affects the quality of well completion. In the existing technology, the gravel-attached water pipe is usually used instead of the conventional well pipe to avoid the well pipe as a gravel-filling process. However, the gravel-attached water pipe is easy to fall off, and the compressive, shear and flexural strength is low. There are still great limitations in the use of de...

AI Technical Summary

Problems solved by technology

[0002] In the process of gravel throwing and water stop in deep wells, due to the small gap between the drilling hole wall and the well pipe and the irregular hole wall, when gravel is filled from the outside of the well pipe, it is easy to cause the gravel to be trapped between the drilling hole wall and the well pipe. "Bridging" between the gaps and the gravel filling is not dense enough, resulting in inaccurate gravel filling height and water stop position, seriously affecting the quality of well completion

In the existing technology, the gravel-attached water pipe is usually used instead of the conventional well pipe to avoid the well pipe as a gravel-filling process. However, the gravel-attached water pipe is easy to fall off, and the compressive, shear and flexural strength is low. There are still great limitations in the use of deep wells

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