OS FREE PIPE - Pipe Freeing Agent for Unweighted Pills



Differential Sticking

Differential sticking is still a common problem during drilling operations, resulting in lost drill strings, lost rig time and costing many millions of dollars. Differential sticking occurs when the drillstring is held in the filter cake across o permeable zone of lower pressure. When differential sticking occurs it is very important to spot pipe freeing agent across the stuck zone as soon as possible since the sticking force increases significantly with time as the string sinks further into the cake. Pipe freeing agents should be spotted quickly and torque worked into the string while jarring.


Product Information 

OS FREE PIPE is a blend of naturally occurring greases and surface active agents designed to give the necessary surfactant and lubricating properties needed to disrupt the filter cake allowing the differential pressure holding the pipe down to equalise and free the string.


Typical Physical Properties 

Appearance   -   Dark amber liquid               

Odour   -   Aromatic

S.G. @ 20oC   -   0.90 – 0.93                             

Flash Point   -   Greater than 150oF

Solubility   -   Oil soluble / water dispersible    

Viscosity   -   Less than 200 Cps



OS FREE PIPE can be blended unweighted allowing the pill to be pumped very quickly, increasing the chances of freeing the stuck string. Spotting unweighted pills will also decrease the hydrostatic pressure in the well reducing the differential sticking force and further increase the chances of freeing the string.



Make a dilution of OS FREE PIPE in base oil or diesel using 3-4 drums of OS FREE PIPE per 50 bbl of finished spotting pill. This material should be spotted in the hole at the depth of the stuck drill pipe. The blended pill should be spotted in the trouble zone against the stuck pipe with 20-30% by vol excess. The spotted fluid should be left for 2-3 hours for soaking and dispersing the cake while working the drill string. The unweighted pill will slowly migrate up the hole so the operation can be repeated 2-3 times if required to ensure a successful job and to free the stuck pipe.

OS FREE PIPE can also be used in combination with weighed OS FREE PIPE WTD spotting pills where well control considerations prohibit the use of multiple unweighted pills.



OS FREE PIPE is packaged in 55 US gallon drums.




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