A float collar is a part near the bottom of the casing string which catches the bottom plug and top plug, and which prevents mud from entering the casing.
The float collar prevents drill mud from entering the casing while it is being lowered, allowing the casing to float during its descent and thus decreasing the load on the derrick or mast.
The aperture of the float collar, which is usually located one joint of casing above the guide shoe, has a valve to prevent backflow of slurry.
A float collar is a part near the bottom of the casing string which catches the bottom plug and top plug, and which prevents mud from entering the casing.