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