Abstract: A packoff pressure prevention system includes an internal pressure sensor to measure fluid pressure within a drillstring. The system further includes an annular vent to, when open, enable fluid to escape from within the drillstring into an annulus. The system further includes a processor coupled to receive pressure measurements from the internal pressure sensor and coupled to signal the annular vent to open if the fluid pressure within the drillstring rises a first threshold amount over a second threshold time.

Abstract: A drilling system can include a downhole assembly with a liner hanger, a liner running tool, a lower wellbore liner, a cementing module, and a drilling tool. The drilling system can provide a single-trip procedure that enables a well operator to drill the wellbore while simultaneously running in a wellbore liner and subsequently cement the annulus around the lower wellbore liner. Once the cement is deposited, a liner hanger can be actuated and a liner running tool released to enable the remaining portions of the downhole assembly to be pulled out of hole while leaving the lower wellbore liner cemented in place.

Abstract: Various embodiments include methods and apparatus structured to increase efficiencies of a drilling operation. An apparatus can be structured to include a sleeve structured to operatively fit over a liner or a casing in a wellbore. The sleeve can be structured with a packer element disposed such that the liner or the casing is capable of rotation within the sleeve when the sleeve with the packer element is operationally non-rotating. Additional apparatus, systems, and methods can be implemented in a variety of applications.

Abstract: Disclosed examples include a ball drop tool located in a drill string. The ball drop tool may be a drilling stabilizer that includes a drilling stabilizer housing having an interior passage to be coupled to a drill string. A at least one stabilizing blade is on an external surface of the housing. The stabilizing blade includes a hollow compartment to hold at least one ball. A gate valve couples the hollow compartment of the stabilizing blade to the interior passage. Gate valve circuitry is coupled to the gate valve for controlling operation of the gate valve to controllably release one or more of the balls.

Abstract: A drilling system can include a downhole assembly with a liner hanger, a liner running tool, a lower wellbore liner, a cementing module, and a drilling tool. The drilling system can provide a single-trip procedure that enables a well operator to drill the wellbore while simultaneously running in a wellbore liner and subsequently cement the annulus around the lower wellbore liner. Once the cement is deposited, a liner hanger can be actuated and a liner running tool released to enable the remaining portions of the downhole assembly to be pulled out of hole while leaving the lower wellbore liner cemented in place.

Abstract: Various embodiments include methods and apparatus structured to increase efficiencies of a drilling operation. An apparatus can be structured to include a sleeve structured to operatively fit over a liner or a casing in a wellbore. The sleeve can be structured with a packer element disposed such that the liner or the casing is capable of rotation within the sleeve when the sleeve with the packer element is operationally non-rotating. Additional apparatus, systems, and methods can be implemented in a variety of applications.

Abstract: Disclosed examples include a ball drop tool located in a drill string. The ball drop tool may be a drilling stabilizer that includes a drilling stabilizer housing having an interior passage to be coupled to a drill string. A at least one stabilizing blade is on an external surface of the housing. The stabilizing blade includes a hollow compartment to hold at least one ball. A gate valve couples the hollow compartment of the stabilizing blade to the interior passage. Gate valve circuitry is coupled to the gate valve for controlling operation of the gate valve to controllably release one or more of the balls.

Abstract: A packoff pressure prevention system includes an internal pressure sensor to measure fluid pressure within a drillstring. The system further includes an annular vent to, when open, enable fluid to escape from within the drillstring into an annulus. The system further includes a processor coupled to receive pressure measurements from the internal pressure sensor and coupled to signal the annular vent to open if the fluid pressure within the drillstring rises a first threshold amount over a second threshold time.

Abstract: Disclosed embodiments include a method and apparatus for dropping a ball in a tool string. One example embodiment is a downhole ball drop tool that releases an activation ball in response to a downlink signal provided from the surface. The ball drop tool is provided as a part of a tool string. A variety of tools connected in a tool string may have a ball seat for receiving an activation ball dropped from the ball drop tool. Once the ball has engaged the ball seat, fluid pressure can be increased in the tool string to activate a mechanism in a downhole tool.