PORTED BY-PASS SUB

The SHARP  Ported By-Pass Sub is designed to be run in a clean-up string where it is desirable 

to open up communication between the ID of the drill pipe and the annulus when POOH. 

It is normally run above the SHARP  Well Patroller* to provide an additional means of 

equalising pressure and fluid flow around the tool should it become full of debris when 

POOH. When run with the SHARP  Well Patroller it is run as a contingency device and is only 

opened if required. 

Unlike conventional single ball drop subs, the SHARP  Ported By-Pass Sub allows fluid in the 

drill pipe above the tool to drain past the ball when the ports are open. 

Other applications for the tool include being run as a drill pipe drain sub and being run in 

conjunction with a SHARP  Single Action By-Pass Sub (SABS*) to provide an additional 

circulation path down hole after the SABS has been closed. 

SHARP do not recommend the use of the PBS for the application of flexing the drill 

pipe. Consideration could be given to flexing the pipe externally instead of internally when 

a suitable internal flexing device is not available. 

Operation 

The tool is RIH in the closed position and, when required, a ball is dropped to open up the 

ports. If desired, fluid can be pumped both through the ports and down through the tool. 

When POOH, the tool is in the open position.

Operational Parameters 

To ensure that the SHARP  Ported By-Pass Sub operates correctly, it is important that pump 

rates are not excessive when landing the opening Ball on the internal ball seat. The 

maximum recommended rates, together with the shear pressures to open the ports, are 

shown in the Table below. 

Important Note: It is not necessary to restrict the pump rate for the complete duration of 

the ball drop period. 

Note: Check the string does not contain a float (if there is a float in the string a reduction 

in Shear Pressure may be noted). 

†Note: Under normal Operating Conditions, Shear Pressures will be within +/- 10% of the 

quoted figures