PBL Multiple Activation Bypass System

The Standard Ball is the most commonly used activation medium for DSI PBL tools. To activate The Tool, a vinyl ball is pumped down to the ball seat. Once on seat, a slight backpressure is created, which forces the sliding sleeve to move to the ports-open position. In this position, sleeve and main body ports are perfectly lined up and 100 % of the drilling fluid exits The Tool through the ports to the annulus. To deactivate the tool, depending on the number of ports in the tool, two or three steel de-activation balls are dropped and pumped down. Theses steel balls, once reached the ports, will create flow restriction as all ports are now plugged. Pressure will build up quickly until a predetermined pressure is reached forcing the vinyl activation ball to extrude through the seat followed by all steel balls. PBL tool is subsequently cycled to ports-closed position and 100% flow is re-established through the Tool and all balls are captured in the Catcher Cage positioned below the Main Body.

Fast Ball is a much denser activation ball in comparison to the standard ball and, is used in applications where high mud weights and high temperatures occur. This feature allows for a quicker activation of the PBL tool which is especially helpful in situations where there is limited or no circulation.

Fast / Hollow Dart, is a heavy dart, which can be used in the highest mud weights, or where mud cannot be circulated e.g. packed-off situation whereby it facilitates activation by gravity drop. It is much faster than a standard ball, hence it reduces activation time significantly. “Descent by gravity only” can be used in wells with a maximum inclination of up to 55° whereas, “Descent by being pumped down” can be used in wells with a maximum inclination of up to 90°.

Split Flow Dart allows drilling fluid to be split partially through the BHA and partially to the annulus. Depending on whether the requirement for split flow is for hole cleaning while drilling ahead or just for cooling MWD tools and motors during a back-reaming operation, the percentage split to BHA and annulus can be customized to suit customers’ specific needs. The percentage split can be pre-set by means of installing suitably sized jet nozzles in the Split Flow Dart and Side Ports subsequent to performing necessary hydraulics calculations. Three steel balls are used to deactivate the tool.