Wellbore Obstruction Removal via Chemical Etching and Magnetic Retrieval

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Solution Overview

Problem

Conventional methods for removing downhole obstructions, such as flapper valves and other tools made from non-ferromagnetic materials, are inefficient and require multiple trips, and there is a need for a method to facilitate the removal and retrieval of debris and pieces using magnetic means.

Innovation Solution

An apparatus and method that projects a medium, such as thermite or a corrosive material, through a nozzle with a specific geometry to separate obstructions into wedge-shaped portions, allowing for their removal in fewer trips and enabling magnetic retrieval by adhering ferromagnetic material to the obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional methods (jars, pigs, fluid jetting) are used to remove downhole obstructions, then physical/mechanical force is applied to move obstructions, but multiple trips are required and removal is inefficient

Engineering Contradiction:
Improveobstruction removal efficiencyVSAvoidnumber of trips required
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces conventional mechanical removal methods (jars, pigs, fluid jetting) with a chemical etching system. The etching composition chemically reacts with and dissolves the obstruction material, eliminating the need for repeated mechanical forcing and multiple trips. This substitution of chemical action for mechanical action directly improves productivity and reduces time loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the approach from mechanical force application to chemical reaction parameters. By controlling the composition, concentration, and contact time of the etching solution with the obstruction, the system achieves complete dissolution in a single operation, thereby reducing the number of trips from multiple to one, improving both productivity and time efficiency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If flapper valves are made from non-ferromagnetic materials (Inconel, stainless steel), then interference with downhole equipment is avoided, but magnetic retrieval of debris becomes impossible

Engineering Contradiction:
Improvedownhole equipment operationVSAvoiddebris retrieval capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces an intermediary substance - ferromagnetic particles suspended in the etching composition. These particles serve as a mediator that bridges the gap between the non-ferromagnetic obstruction material and the magnetic retrieval system. The ferromagnetic particles adhere to the debris after chemical dissolution, enabling magnetic retrieval without changing the base material composition, thus maintaining reliability while enabling ease of operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If progressive enlargement of flowpath through center of flapper valve is used, then obstruction is removed, but multiple trips and complex nozzle geometry changes are required

Engineering Contradiction:
Improveobstruction removal speedVSAvoidnozzle geometry variations
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical process of progressive nozzle geometry changes with a chemical etching system. The etching composition uniformly dissolves the obstruction material regardless of the valve's internal geometry, eliminating the need for multiple nozzle configurations and progressive enlargement steps. This chemical approach simplifies the device while improving productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The etching composition serves as a universal solution that can handle various obstruction types and geometries without requiring device modification. A single nozzle configuration can effectively remove different kinds of obstructions (flapper valves, debris, tools) through chemical action, providing multi-functionality that eliminates the need for multiple specialized nozzles and complex geometry variations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively removes obstructions like flapper valves in fewer trips and allows for the magnetic retrieval of debris, improving operational efficiency and reducing the complexity of debris recovery.

Implementation Method 1

a nozzle at an end of the body, the nozzle adapted to project the medium in a direction generally parallel to the longitudinal axis of the body

Methodology Applied
Scientific EffectJet: Jet

Implementation Method 2

enabling magnetic retrieval by adhering ferromagnetic material to the obstruction

Methodology Applied
Scientific EffectMagnetism: Magnetism

Data Source

PatentEP3585974B1Apparatus and methods for overcoming an obstruction in a wellbore
Publication Date: 2022.04.06 ROBERTSON INTELLECTUAL PROPERTIES LLC
  • EP3585974B1 patent drawingFigure 1A
  • EP3585974B1 patent drawingFigure 1B
  • EP3585974B1 patent drawingFigure 2A

AI summary

Apparatus and methods for penetrating a downhole target within a wellbore include providing a body with a longitudinal axis, a first end, and a second end into a wellbore, the body having a nozzle at the first end. The nozzle is adapted to project a medium in a direction generally parallel to the longitudinal axis to affect a downhole target, An actuator in communication with the medium is usable to initiate the apparatus. The nozzle can be provided with a geometry configured for projecting the medium in a pattern that separates the downhole target into at least two portions. The medium can include a ferromagnetic material that becomes associated with the downhole target to facilitate recovery of the target or portions thereof using a retrieval device having a magnetic element.