The ram BOP is designed to seal of the tubular annulus or the hole. With the ram BOP in the closed position, such operations as circulating drilling fluid, releasing pressure and killing the well can be performed by means of the spool beneath the BOP or pipelines connected to the side outlet of the BOP body. Under special circumstances, the ram BOP with variable bore ram can seal off the annular space between the casing and the pipes of various sizes within a certain range.