The Composite Bridge Plug is made from composite material and easy to drill out. It is mainly composed of mandrel, rubber, slips, cones, protection bowls, release/start pins, lower sub and so on. The composite bridge plug is mainly used for provisional plugging in oil and gas well, and fracturing construction Working principle The opposite power produced by setting tool (wire line or transmitting hydraulic pressure in oil tube) acts on the lower sub, shears the starting dowels and exerts compressive force on rubber through cone. Inside the tension range slips dehisce and inlay the in wall of the casing, rubber expand to the in wall of the casing and seal up it, finish setting. When the tension rises to the shear rating, the starting dowels be sheared and the setting tool separates from the bridge plug, finish releasing. After taking out the setting tool, the frac ball that be put into the well will work hermetically with the head face of the mandrel. The plug can be quickly drilled out under the necessity of the after steps Drilling out Recommend the use of special milling tools. Recommend rotation rate: 60~150rpm, bit weight: 5~15kN, viscosity of drilling plug fluid:15~30mPas and minimum cyclic velocity: 36.6m/min, to make sure the debris circulates out. After the preparation is done, start the screw drill and drill slowly into the bridge plug. Ensure continuous drilling speed by applying drilling pressure. The torque added to the drilling tool should not be greater than the recommended value. Excessive drilling pressure increases the friction resistance of the pipe string and results in large pieces of debris which must be salvaged separately.