Wireline Stand Offs (WLSO)

A cost effective way of preventing stuck cable during wireline logging operations

Impact Selector’s Wireline Stand Off (WLSO) technology protects the jars by improving tension transmission to the cable head in sticky or tortuous holes. By reducing cable contact with the formation by up to 99%, Impact Selector’s Wireline Stand Offs are able to eliminate the differential sticking risk. These stand offs also reduce cable pressures, which may otherwise result in keyseating. Impact Selector’s advanced WLSO technology is proven to be a cost-effective way of preventing stuck cables and expensive fishing jobs during wireline logging operations.

A sophisticated WLSO planning package employs LWD gamma and pore pressure data to identify sticky zones in the well. Tolerance to sticking is estimated as a function of overbalance with depth and maximum pull available.

The Impact Selector WLSO deployment plan takes into account cable forces, hole trajectory, and petrophysical objectives to maintain cable suspension away from these sticky zones during the logging run.


  • Protects jar firing and resetting in a sticky hole by improving tension transmission down to the cable head
  • Minimizes cable contact over sticky zones in the wellbore, and diffuses cable pressures that may induce differential sticking or keyseating, reducing fishing risk
  • WLSO planning package determines relative sticking risk between tools and cable at all depths in the well. Sensitivity to pore pressure and capacity for surface pull is assessed
  • Permits safe wireline conveyance in high risk environments where costly pipe conveyance operations may be the only viable alternative to gain data or samples


  • Diameter sizes: 2.05” and 2.95”
  • May be stripped over during fishing operations if necessary
  • 12 fins spread cable pressure onto the formation, reducing keyseating forces and providing low resistance to cable torque
  • Cable inserts provide a uniform snap fit on any logging cable to within 0.002” regardless of cable condition or manufacturer
  • Imparts no damage to the cable from clamping, but allows sufficient grip to avoid slippage under high tensions
  • Does not interfere with cable telemetry system
  • Possesses a low angle of attack and streamlined profile that avoids hang-up points in the wellbore





The WLSO lifts the cable away from cake and formation.

The WLSO lifts the cable away from cake & formation WLSO-205 , 295

WLSO-205 is deployed when the hole is drilled with 3-1/2” drillpipe (leaving sufficient clearance for stripping over to logging tools), or if the wireline fishing grapple is sizes for the fishing neck (e.g. 2-5/16” or 2-3/8”).

WLSO-295 is deployed when the hole is drilled with 4” drillpipe or greater, or if the wireline fishing grapple is 3-3/8” or larger.