CPTWD

CPTWD™ (Cone penetration test while drilling)

is an Italian  Patent and trademark™ of Massimo Sacchetto.

Some others have tried to push a piezocone with wireline rods, but it's the only method which has been widely used, engineered and studied with comparative deep tests.

CPTWD is a method for carrying out CPTU tests without penetrometer using the same wireline drillstring which is used for continous core drilling.

It has been made by Massimo Sacchetto, developed and used by Company SPG until 2015

The first attempt to push a cone with a drill rig was made in 1989 using a dummy cone installed in a wireline corebarrel, measuring the thrust, torque, water flow for pushing the cone at a constant Rate of Penetration.

A special wireline bit was designed for the installation of the cone, and this constituted the basis of CPTWD.

Ten years later (1999) the dummy cone was replaced by a "memory-cone" (memocone) and the first test was done.

The CPTWD is the acronymous of Cone Penetration Test While Drilling. Basically it can be considered as an integration between a wire-line system (core barrel, non coring device, cable recovery system, etc), piezocone and the MWD (Monitoring While Drilling) system.