JRI Fireside chat with Scott Macmillan Tues. Nov 28 @ 9:00 Perth/12:00 Sydney, page-351

https://www.academia.edu/29930954/DOWNHOLE_WIRELINE_MECHATRONICS_AND_DRILLSTRING_VIBRATION_DYNAMICS

One method that is being conventionally used to reduce the likelihood of differential sticking of wirelines during logging, especially in oilfield operations in deviated wells, is the use of wireline stand-offs (i.e. Centralizers).

The wireline stand-off device ameliorates the effects of differential sticking and key-seating of the wireline by eliminating direct contact of the wireline tool or the logging cable with the borehole wall by lifting the tool string away from the side wall of the bore during the logging operation.

This is typically achieved by clamping an array of stand-offs onto the outside of the wireline, resulting in:

• Lower contact area per unit length of openhole.
• Lower applied pressure of the wireline against the borehole wall
• Lower dragging resistance when conveying the wireline in or out the hole.
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The conventional stand-offs have fluted fins (straight blades) cut along their external body to allow easy movement through mud cake and other debris which usually build up at the borehole wall during drilling operations.

Low-friction Teflon stand-off conveyance accessory, typically used by Schlumberger, reduce the frictional drag forces acting on a tool string in a deviated well by effectively reducing the friction coefficient.

More efficient low-friction stand-off products derived from the Free-roller principle have been developed by oil & gas companies to mitigate differential sticking and increase the net pulling-down force while helping the tool string ride over borehole imperfections and debris.