Chemical pipe cutting is a wireline operation that utilizes an electric tool and a halogen fluoride chemical reactant to perforate and weaken pipe, enabling its subsequent removal (pipe recovery). Originally introduced in the 1950s as a patented process exclusive to a single wireline company, chemical cutting has now become widely adopted across the industry. Today, most electric-wireline service providers offer this technique, making it the predominant method for cutting pipes due to its efficiency and effectiveness.
Courtesy of Versa-line – https://versa-line.com/
The process involves the following components and mechanisms:
Tool Design
The chemical cutting tool comprises a body with a series of flow jets around its lower section. It contains:
- An ignition system to initiate a propellant charge
- A reservoir for the chemical reactant (halogen fluoride or bromine trifluoride)
- Pressure-actuated slips to prevent vertical movement during operation
Operating Principle
- The propellant charge is electrically ignited, generating high pressure and temperature.
- The reactive chemical is forced through the jets by the propellant gases.
- The jets impinge the chemical on the pipe wall at high velocity.
- The halogen fluoride chemically reacts with the pipe metal, eroding and perforating it circumferentially.
- The reaction products are harmless iron salts that dissipate in the well fluid.
Advantages
- Efficiency: Minimizes rig time compared to other methods.
- Clean Cut: No flaring, burrs, or swelling occur on the cut pipe, eliminating the need for dressing before retrieval. The image below shows the result of cut pipe from using a chemical cutter.
Pipe was cut using a chemical cutter. courtesy of Versa-line – https://versa-line.com/
- Safe: The chemical reaction produces harmless salts that don’t damage nearby casing and dissipate quickly in well fluids.
Operational Parameters
- Requires a minimum of 100 ft of fluid above the tool for successful operation.
- Well fluid must be clean and free of lost circulation materials.
- Rated for up to 18,500 psi hydrostatic pressure and 450°F temperature.
- Compatible with most tubing, drill pipe, and casing sizes.
Chemical cutting tools revolutionized wireline pipe recovery operations, offering a safe, efficient, and cost-effective solution compared to traditional mechanical cutting methods.
References
The Guide to Oilwell Fishing Operations: Tools, Techniques, and Rules of Thumb (Gulf Drilling Guides) by Joe P. DeGeare, David Haughton, Mark McGurk
Versaline Services wireline solution – https://versa-line.com/pipe-recovery/
