CBS,CASING BUOYANCY SYSTEM, OILFIELD USE

The casing buoyancy system

The SWS's casing buoyancy system is used for lessening the weight of the casing string as it is lowered into the wellbore.

The float shoes's nose is designed to withstand high differencial pressure and has a bullet shape to guide the leading end of the casing to tottom

The nose is sheared off once the floatation collar valve has been deactivated 

The floatation collar incorporates the control valve with air internally and the upper casing section that is filled with fluid. Once the casing has been run to depth, surface pressure is applied to deactivate the valve , allowing fluid above to flow into the lower casing as the air migrates to the surface. 

After all the air has migrated to the surface, the entire casing string will be filled with fluid, then the float shoe nose is pumped off and conventional single stage cementing can be performed. 

MAIN FEATURES 

1-Field adjustable floatation control valve pressure. 

2-No ports or plugs in the body of the floatation collar , shear pins are installed internally.

3-Anti rotation features for the plugs and floatation control valve.

4-Snap ring locks control valve open after conversion. 

5-Bottom plug incorporates an alignment sleeve to maintain concertricity with the control valve during displacement.