Types of Drill pipe and Tubular Cutter

There are many different types of tubular cutters available in the oil & gas industry. Applications are commonly to sever drill pipe, coil tubing, or retrieve the completion string from the well by cutting a tubular joint or at the cut to release packer assembly.

As with all deployments into the well,  it is important to plan and choose the correct cutter for each application along with its deployment method. Ideally, all cutting operations are preferred to be conducted with the drill pipe or completion string in tension, usually string weight plus 10%, where possible. Damage to the casing, or behind tubing, may occur if the wrong cutter is chosen. Some cutters are not able to cut in a gas environment, so fluid level and type may become a factor to consider. If an explosives cutter is to be run with wireline tractor conveyance, then there may be a high risk that the tractor may part or fail on cutter activation. All cutting tools should be used within their specified temperature and pressure limits.

Types of Cuter on the Market

Cutting options can broadly be placed into the following categories:

• Explosives Cutters
• Electromechanical Cutters
• Chemical Cutters
• Radial Cutting Torch

Explosive Cutters:

Explosives cutters can be broken down further into the following applications.

• Drill Collar Severing Colliding Tool:These are used to  sever pipe in recovery operations, utilising precisely timed explosive charges to cut through drill collars and other heavy-duty materials. The cutting attempt should be made above the struck point. Significant pipe damage and splitting will occur during the process.
• Shaped Charge Cutters:These employ explosive charges to focus a blast into a metal jet that penetrates and cuts the target material. They are used for precise severance in downhole operations. Flaring of the tubular is expected during the cutting process but has been improved to minimise this effect. Some cutters are designed  to split the collar and release the tubular in this manner. Consideration is needed when designing a completion to ensure the cutter can be accurately positioned for a cut to release packer. A landing nipple above the packer can assist in this process.

Note: While explosives cutters are common in the oilfield they may be difficult to transport to the wellsite on short notice due to the individual country security restrictions. Explosive cutters can cut with the string in tension or compression.

Chemical and Radial Cutting Torch:

• Chemical Cutters: These utilise chemicals like bromine trifluoride to dissolve metals cleanly without debris. They are particularly useful in sensitive or difficult-to-access environments, however there are significant safety precautions that are needed to be able to deploy this equipment due to extremely harmful chemicals and their bi-products.
• Radial Cutting Torch (RCT): Utilizes a plasma jet to cut through materials. This tool is non-explosive and can be deployed rapidly worldwide due to fewer transport restrictions, although there may be some exceptions to this.
• Due to their cutting action there is no flaring of the tubular. These type of tool are typically the only option to cut coil tubing.

Note: Due to the nature of these tools it is important to have them centralized correctly. Both of these tools can be susceptible to becoming stuck to the tubing wall during the cutting process. Ideally activated with the string in tension plus 10%.

Electromechanical Cutters:

• Electromechanical Cutters: These cutters use rotating or reciprocating cutting heads or blades that are powered electrically and monitored from surface during the cut process. These types of tools are ideal for environments where explosives or chemicals pose a risk, or where it's logistically not possible to transport them to the wellsite. While many tool suppliers state that their tools can cut in both tension and compression, a string in tension would always be optimal. Where the string is in compression, consideration is needed to avoid issues with bladed tools becoming stuck on tubular break through, or when a tool stalls during a cut that is unable to restart due to limitations in their design. Tool retrieval can become challenging when an electrical short circuit occurs during the cutting process. As with many cutters, accurate centralisation is essential for success.

Note: One major advantages of electromechanical cutters over other cutting methods is the potential to complete multiple cuts during one decent into the well.

Vigor Non-explosive Downhole Cutter

• Non-explosive Downhole Cutter consists of an anchoring device and a
• The anchoring device anchors the cutting tool to the inner wall of the pipe to be cut, preventing the tool from moving during the cutting process; the combustor produces a high-temperature and high-pressure molten metal fluid that scrubs and ablates the pipe, thus achieving the purpose of the cutting.
• Safety option is considered, when the instrument cannot be unanchored during job, through the input of a 230mA current or lift the wireline more than 1.6T force to shear the shear pins and release the tool string.

The following is a field test case conducted by Vigor's team of engineers at an oil field site in China for reference:

Current overload protection shutdown, downhole pump card, pre-cut 2-3/8" tubing, cutting depth 825.55m. TheΦ43 Wireline Non-explosive Downhole Cutter was used for construction, and the suspension weight was lifted by 8t, and the cutting was successfully completed at 804.56m, and the total cutting time was about 6min.The incision is neat, no flanging, no expansion diameter.

Up to now, the Non-explosive Downhole Cutter from Vigor has become one of the most popular downhole drill pipe cutting tools, the tool has been highly recognized by end users for its high reliability, if you are interested in Vigor's Non-explosive Downhole Cutter, please do not hesitate to get in touch with us.

For more information, you can write to our mailbox info@vigorpetroleum.com & marketing@vigordrilling.com