SureLOC

Electronically controlled cable release device

Reliable cable release under the most challenging tool-sticking situations

Mechanical weakpoints are conventionally used in operations with high cable tension to safely separate the cable from a stuck tool downhole. Different-strength weakpoints are used to ensure breakage before exceeding the cable safe working load. Under certain conditions, the surface-applied tension is too high or cannot be effectively transmitted to break the weakpoint. The result is a lengthy cable-attached cut-and-thread fishing operation or in, the worst-case scenario, a broken cable left in the well on top of the fish.

The higher-rated release spring and prepackaged release bobbin assembly of the SureLOC device deliver superior efficiency and consistent performance.

To overcome the operational limitations of mechanical weakpoints and previous-generation electronically controlled release devices (ECRDs), Schlumberger developed the SureLOC 12000 and 8000 cable release devices. Installed in the wireline logging head, the SureLOC 12000 device is activated by a software command and electrical power to reliably release the cable under a wide range of downhole conditions. Combined with TuffLINE torque-balanced composite wireline cable, the electronic release reliability for the SureLOC device exceeds 97%.

SureLOC 12000 and 8000 release devices can be complemented with inline addressable electronically controlled release devices positioned strategically along the toolstring.