Pressure-balancing one-way valve for coiled-tubing layering fracturing

Abstract

The invention discloses a pressure-balancing one-way valve for coiled-tubing layering fracturing. The pressure-balancing one-way valve comprises an upper joint, a limiting connecting sleeve, a body, a sealing head and a lower joint which are successively connected, wherein the inner part of the upper joint is of a hole-shrinkage cavity structure, a check ring and a sealing ball are mounted in a cavity in the upper part of the upper joint, the sealing ball is mounted at a hole shrinkage part, the check ring is mounted above the sealing ball, the lower end of the upper joint is fixedly connected with the sealing head and the sealing head is sleeved on the upper joint, the limiting connecting sleeve is sleeved on the upper joint, the body is sleeved on the limiting connecting sleeve and the sealing head and fixedly connected with the limiting connecting sleeve, a sliding gap is formed between the sealing head and the limiting connecting sleeve, and the lower joint stretches into the lower end of the body and is fixedly connected with the body. The pressure-balancing one-way valve for coiled-tubing layering fracturing has the characteristic of simple structure; and due to the adoption of the pressure-balancing one-way valve for coiled-tubing layering fracturing, the effects of packing and setting of an annular mechanical packer can be effectively improved, the setting and the packing are facilitated, and the abrasive perforating and the reverse-circulation sand-washing deblocking of a sand blower are facilitated.

Description

[0001] technical field [0002] The invention relates to the technical field of downhole tools for oil and gas wells for petroleum development, in particular to a pressure balance check valve for layered fracturing of coiled tubing, the pressure balance check valve is mainly used for downhole fracturing and acidizing construction. Background technique [0003] Most oil and gas reservoirs in China have multiple production layers in the vertical direction, and most of them are thin interbeds, and some even have more than 5 layers. The implementation of fracturing and acidizing is an important transformation measure to realize the production increase of oil and gas wells. For wells completed with casing, the more advanced technology at this stage is the construction method of coiled tubing running down the well multiple times to locate and isolate different layers. Empty packers are used to facilitate layer-by-layer acid fracturing after layer-by-layer sandblasting and per...

AI Technical Summary

Problems solved by technology

However, there is no pressure balance check valve used with the packer in the prior art, so that the inner passages above and below the packer cannot be isolated simultaneously with the outer passages, which is not conducive to layer-by-layer fracturing and acidizing reconstruction

After retrieval, there are currently no related technical publications applicable to pressure balance check valves for coiled tubing layered fracturing in domestic and foreign journals, magazines or patent databases.

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