Extended-Reach Downhole Tool Using Valve-Driven Axial Oscillations
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Solution Overview
Problem
Drilling and completion operations face challenges in reaching required depths due to significant frictional forces between tubing and the casing or formation wall, often leading to lock-up situations where snubbing force from the surface cannot overcome these forces.
Innovation Solution
A downhole tool with a fluid flow control system that includes a rotatable pilot valve and a poppet valve, which cycles between open and closed positions to generate axial oscillations, overcoming friction by creating vibratory effects during the insertion and retrieval of drill strings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If extended reach tools are used to overcome frictional forces, then the ability to reach required depth is improved, but the device complexity increases
Solution Approach 1:
The patent applies mechanical vibration by cycling the flow control valve between open and closed positions to generate axial oscillations in the tubing. These vibrations reduce frictional forces between the tubing and casing/formation wall, enabling the tool to reach greater depths without increasing overall device complexity. The vibration mechanism is integrated into the existing tool structure through the valve system.
Solution Approach 2:
The patent employs periodic action through the cyclic operation of the flow control valve, which alternates between open and closed states. This periodic valve operation creates repeated pressure changes that generate sustained axial oscillations, allowing the tubing to overcome static and kinetic friction periodically throughout its descent, thereby achieving extended reach capability.
2Force
If snubbing force is applied from the surface to overcome friction, then the force to move tubing is increased, but the tubing may lock up and become immobile
Solution Approach 1:
The patent uses mechanical vibration generated by cyclic valve operation to reduce frictional forces between the tubing and surrounding casing or formation wall. These vibrations transform the friction characteristic from static to dynamic, preventing the tubing from locking up under snubbing force and maintaining reliable mobility throughout the insertion and retrieval operations.
Solution Approach 2:
The patent converts the harmful effect of frictional forces that cause tubing lock-up into a beneficial effect by using the same friction interface to generate useful axial oscillations. The cyclic pressure changes from valve operation create vibrations that actively reduce friction, turning the friction problem into a solution that enhances tubing mobility while allowing snubbing force to be applied effectively.
3Ease of operation
If cyclic pressure changes are generated to reduce friction, then the ease of operation is improved, but the energy consumption increases
Solution Approach 1:
The patent implements self-service by using the existing fluid flow through the tool to drive the pilot valve and flow control valve cyclically. The pressure differential created by the tool's own operation powers the valve mechanism, generating the necessary vibrations to reduce friction without requiring external energy input. The system serves itself by converting its operational pressure changes into the vibration mechanism needed for ease of operation.
Data Source
AI summary
A downhole tool comprises a tool housing defining a flow passage therethrough from a first to a second end thereof. A poppet is axially movable on a poppet mandrel positioned in the tool housing. The poppet mandrel has at least one outlet port defined therein. A pilot valve is rotatable about the poppet mandrel. Rotation of the pilot valve opens and closes the at least one outlet port in the poppet mandrel to permit and block flow therethrough, and wherein the opening and closing of the at least one outlet port moves the poppet axially on the poppet mandrel.