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.