Downhole Safety Tools for Concentric Strings

Abstract

This invention discloses a downhole safety tool used forconcentric-tubecolumns. The tool includes an upper valve body, a main valve bodyand a lower valve body;the outer edge of the bottom end of the lower valve body is connected with the outer edge of the top end of the main valve body through an outer tube, the main valve body is provided with a valve core, and an inner cylinder is arranged in the lower valve body; the top end of the valve core is connected with the inner edge of the bottom end of the upper valve body, and the bottom end is connected with the inner cylinder; the bottom end ofthe main valve body is connected with the lower valve body; the upper valve body is provided with a central flow passage to be communicated with a central cavity body of the concentric-tuber column and a first side hole passage to be communicated with an annular cavity body of the concentric-tube column; a first liquid chamber and a second liquid chamber which are communicated with each other areformed in the upper valve body,a pilotpipeline port is formed in the top end of the second liquid chamber, and the inside of the first liquid chamber is provided with afirst plunger sliding along theaxis of the first liquid chamber.

Description

technical field [0001] The present application relates to but not limited to offshore oil extraction tools, especially a downhole safety tool for concentric pipe strings. Background technique [0002] According to the national offshore oil safety production regulations, downhole packers should be installed in offshore gas wells, self-flowing wells, and self-overflow wells, and downhole safety valves should be installed below 30 meters of the seabed to prevent downhole fluids from accidentally returning to offshore platforms and Hazard to the marine environment. [0003] At present, my country's offshore oil wells basically use electric submersible pumps, screw pumps and hydraulic jet pumps for oil production, and downhole safety valves are installed on the oil pipes, such as EU patent (EP1069279A2), Chinese patent (CN201510896633), Chinese patent (CN201610626036), Chinese patent (CN201410096801) , Chinese patent (CN201210037754), Chinese patent (CN201410756715) and other dow...

AI Technical Summary

Problems solved by technology

[0004] With the increasing development of hydraulic jet pump technology, technologies such as concentric tube hydraulic jet pump, parallel tube hydraulic jet pump, and sand discharge and oil production jet pump (CN20131027553) are emerging continuously. The existing downhole safety valves cannot be installed and used in production strings using concentric pipes, which cannot meet the needs of offshore safety production

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