Slickline Skirted Magnet

Description

Slickline Skirted Magnet

Technical Description and Specifications

The Slickline Skirted Magnet is a specialized non-fishing junk retrieval tool used to recover small, metallic, ferrous debris (e.g., filings, punch-out slugs, small broken shear pins, or small fragments of wire) from the bottom of the wellbore or a specific seating nipple profile. The integral skirt design enhances debris capture and retention.

Key Technical Specifications and Operation

• Function: To magnetically attract, capture, and retain small ferrous metallic debris, ensuring the wellbore is clear for subsequent flow control, logging, or perforating operations.

• Design: Consists of a strong, permanent rare-earth magnet assembly encased in a non-magnetic housing, typically mounted directly below the stem. The critical feature is the skirt (or boot), a sleeve extending below the magnet face, designed to guide the magnet centrally over the debris and protect the collected debris from being washed off during retrieval (POOH).

• Magnetic Material: Utilizes high-strength permanent magnets, commonly Neodymium (NdFeB), known for their powerful magnetic field relative to their size, ensuring maximum lifting capacity.

• Debris Protection: The skirt’s clearance is optimized to allow debris to pass up to the magnet face while providing an obstruction to prevent contact with the tubular walls, minimizing the risk of the collected junk being scraped off during retrieval.

• Operating Procedure: The tool is lowered to the target depth and allowed to soak briefly. Gentle jarring or rotating (when possible) can sometimes help position the junk against the magnetic face before retrieval.

• Connection (Customizable):

  • Standard interfaces include proprietary slickline pin threads.

  • Custom order connections are available for compatibility with non-standard threads and proprietary quick-connect systems.

• Material (Customizable):

  • Housing: High-strength alloy steel. The skirt section is often Brass or Non-Magnetic Stainless Steel to avoid interfering with the magnetic field while providing abrasion resistance.

  • Custom material options are available, including NACE MR0175 compliant alloys for sour service and specific non-magnetic grades for the housing and skirt.

• Critical Parameters (Customizable OD and Magnetic Strength):

  • Outer Diameter (OD): The skirt OD must be accurately sized to the inner diameter of the tubing to maximize debris capture area.

  • Magnetic Strength: Custom magnets with specified magnetic flux density (measured in Gauss) can be ordered for recovering exceptionally heavy or weakly magnetic materials. Clients must specify the target tubing ID and the required magnetic pulling force when placing a custom order.