Downhole Propellant Charge Tool for Tubular Ablation and Removal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for removing casing and cement in well abandonment operations are slow and costly, as they rely on milling tools, hydro-abrasive cutters, or perforating charges, which are inefficient in creating large holes or removing tubulars and associated cement effectively.

Innovation Solution

A tool that uses a stream of combustion products generated by a propellant source, combined with a modifying agent, to ablate, cut, displace, heat, abrade, or erode tubulars, offering faster and more resource-efficient removal by creating a thrust effect and anchoring the tool to manipulate tubulars.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional milling tools or hydro-abrasive cutters are used to remove casing and cement, then the removal process is gradual and controlled, but the operation becomes very slow and expensive

Engineering Contradiction:
Improvecontrolled removalVSAvoidremoval speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces mechanical milling tools and hydro-abrasive cutters with a propellant charge system that uses controlled explosive deflagration to remove casing and cement. The combustion products generate a thrust effect that rapidly erodes and removes the tubulars and cement, substituting gradual mechanical removal with a high-energy chemical reaction that achieves both speed and control.

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

Solution Approach 2:

The patent changes the energy delivery parameters from low-intensity continuous mechanical or hydro-abrasive action to high-intensity pulsed combustion energy. By controlling the propellant burn rate and combustion chamber pressure, the system delivers energy in a controlled manner that maintains precision while dramatically increasing removal speed compared to conventional methods.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If perforating charges are used to penetrate casing wall, then small holes are created for fluid communication, but large holes desirable for effective removal are not achieved

Engineering Contradiction:
Improvehole sizeVSAvoidremoval effectiveness
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent merges multiple perforating charge functions into a single integrated system. Instead of creating multiple small holes with separate perforating charges, the propellant charge creates a unified large-volume combustion chamber that generates a concentrated thrust effect. This combined approach produces a single large effective opening that achieves both the penetration function and the large-hole requirement for effective casing and cement removal.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If milling tools are used to gradually cut away metal and cement, then precise control is maintained, but the operation becomes very time consuming

Engineering Contradiction:
Improvecutting controlVSAvoidoperation duration
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent employs periodic action through the controlled deflagration process. The propellant burns in a controlled sequence, with the combustion wave progressing through the charge in a timed manner. This periodic energy release maintains control over the removal process while reducing the total operation time from hours or days of gradual milling to minutes or seconds of controlled combustion.

Inventive Principle:
Principle #19Periodic action

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 tool significantly reduces the time and cost associated with removing casing and cement by using a stream of combustion products to efficiently cut, ablate, or displace tubulars, allowing for faster well abandonment and reduced operational expenses.

Implementation Method 1

upon ignition of the propellant source, the propellant source is adapted to deflagrate, creating at least one stream of combustion products

Methodology Applied
Scientific EffectDeflagration: Deflagration

Implementation Method 2

the/each stream of combustion products and/or the modifying agent may erode, ablate, abrade or remove at least a portion of the tubular to be manipulated

Methodology Applied
Scientific EffectAblation: Ablation

Implementation Method 3

the/each stream of combustion products and/or the modifying agent may erode, ablate, abrade or remove at least a portion of the tubular to be manipulated

Methodology Applied
Scientific EffectErosion: Erosion

Implementation Method 4

the propellant source is adapted to deflagrate, creating at least one stream of combustion products

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 5

the/each stream of combustion products may heat the tubular to be manipulated

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3221550B1Downhole tool with a propellant charge
Publication Date: 2021.04.14 SPEX CORP HLDG LTD
  • EP3221550B1 patent drawingFigure 1~2
  • EP3221550B1 patent drawingFigure 3~4
  • EP3221550B1 patent drawingFigure 5~6

AI summary

A tool for manipulating a tubular, such as casing or production tubing, in a downhole environment, this described. The tool comprises a housing defining a chamber, the chamber having at least one outlet, a propellant source located within the chamber and an ignition mechanism for igniting the propellant source. Upon ignition of the propellant source, the propellant deflagrates, creating at least one stream of combustion products, the chamber directing the stream of combustion products through the/each outlet, towards the tubular to be manipulated, the/each stream of combustion products combining with at least one modifying agent to manipulate the tubular.