Wel-lok M2M SCTTM

Reducing Unwanted Sand Production

Wel-lok M2M™ – An Overview of the Technology

The Wel-lok M2M™ technology consists of utilizing a modified thermite chemical reaction heater to melt bismuth-based alloys downhole. The melted alloys have a viscosity similar to water, and a specific gravity 10 times that of water, allowing them to flow into the smallest areas of a wellbore without the need of any surface pumping equipment. As the alloys cool and solidify, they expand to provide a seamless gas tight seal that is non-corrosive and not affected by H2S or C02.

Summary of Wel-lok M2M SCT™ Features

Seals the annulus as well as the wellbore with advanced bismuth technology

No need to damage the casing with perforations as melted alloy flows through the sand screen

Molten alloy is gravity fed, eliminating the need to pump or squeeze

Utilises modified thermite chemical reaction heater to quickly melt bismuth based alloys

No moving parts means reliable operation

No maximum run rate

Easy and quick to deploy in a single trip intervention

Benefits of Wel-lok M2M SCT™ for Sand Control

Reduced intervention costs

Reduced sand production

Extends production life of the well

Increased oil production

Non-corrosive and not affected by H2S or CO2

Reduced contingent liabilities

Reduced environmental impact

Temperature ranges up to 160 °C

Available in a range of sizes to suit API & non API tubing and casings


The Wel-lok M2M SCT™ (Sand Control Tool) has been developed to eliminate unwanted sand production by isolating both inside the completion string and in annulus of an open hole gravel pack completion (OHGP). This can be done without damaging the completion string with perforations or squeezing as is required for traditional methods. Due to its viscosity and density, the liquid alloy will flow through the sandscreen and into the open hole with gravity, completely isolating the sand producing zone.

Flow prior to tool setting

Flow prior to tool setting

Flow after tool setting

Flow after tool setting

BiSN WEL-LOK M2M SCTTM Current Qualified Tools  
(in) (A)
(ft) (B)
4" screen x 7" liner2.7521400
4" slotted liner x 6"
open hole
5" screen x 8.5"
open hole
5 1/2" screen x 9.5"
open hole
* custom sizes available

BiSN tool range

You can view or download a PDF data sheet of all our other tools by clicking the links below.