Float Collar

Float collar is a casing coupling with check valve. It is one of the casing accessories. In deep wells and special wells, it can be used in combination with casing floating shoes to improve the safety of cement injection operations. In the process of casing running, one-way flow of drilling fluid in the annulus is realized to prevent the backflow of cement slurry during cement injection and to realize pressure relief and setting after cementing impact, which helps to improve the cementing quality of the cement ring and casing; at the same time, the buoyancy of the casing string is adjusted by pouring drilling fluid which is run into the casing string, so that the casing hanging weight can meet the design requirements of the casing operation.

When using the casing float collar, it is to control the lowering speed of the casing string to prevent the pressure variation caused by the rapid lowering, which may cause seal failure or crush the fragile formation. By pouring drilling fluid into the casing and adjusting the pressure difference between the inside and outside of the casing, it can effectively prevent the casing from being crushed.