Abstract: Systems and methods for casing drilling riserless sections of a subsea bore may include casing drilling a section of a bore for a casing of the subsea bore to a predetermined depth. The method also may include, while casing drilling the section of the bore, obtaining information indicative of pore pressure and fracture pressure of a geological formation through which the section is casing drilled, and determining a pressure range based at least in part on the pore pressure, the fracture pressure, and a modification to mechanical properties of the geological formation due to the casing drilling of the section. The method further may include selecting, based at least in part on the pressure range and the predetermined depth, a pressure of the bore for casing drilling the section.

Abstract: A method of using a liner assembly comprises inserting the liner assembly into a wellbore, the liner assembly having an annular packer and a port collar. The method further comprises closing fluid flow through a lower end of the liner assembly, actuating the annular packer into engagement with the wellbore, and actuating the port collar into an open position to open fluid communication between an interior of the liner assembly and the wellbore. The method further comprises pumping cement into the wellbore through the port collar at a location above the annular packer and actuating the port collar into a closed position to close fluid communication between the interior of the liner assembly and the wellbore.

Abstract: A swivel configured to rotationally decouple an upper section of a work string from a lower section of the work string. The swivel includes an upper body coupled to a lower body by a ring member and a plurality of shearable members. The lower body has a plurality of teeth members that engage a plurality of teeth members of the ring member. Rotation of the upper body is transmitted to the lower body by the ring member. The upper body is rotatable relative to the lower body when the shearable members are sheared.

Abstract: A swivel configured to rotationally decouple an upper section of a work string from a lower section of the work string. The swivel includes an upper body coupled to a lower body by a ring member and a plurality of shearable members. The lower body has a plurality of teeth members that engage a plurality of teeth members of the ring member. Rotation of the upper body is transmitted to the lower body by the ring member. The upper body is rotatable relative to the lower body when the shearable members are sheared.

Abstract: A method of using a liner assembly comprises inserting the liner assembly into a wellbore, the liner assembly having an annular packer and a port collar. The method further comprises closing fluid flow through a lower end of the liner assembly, actuating the annular packer into engagement with the wellbore, and actuating the port collar into an open position to open fluid communication between an interior of the liner assembly and the wellbore. The method further comprises pumping cement into the wellbore through the port collar at a location above the annular packer and actuating the port collar into a closed position to close fluid communication between the interior of the liner assembly and the wellbore.