A fail-safe method to cement a section of casing string to a formation is provided. The method includes providing the casing string in a wellbore, the casing string comprising a stage tool, a packer, and a sensor. The packer is located vertically below the stage tool and vertically above the sensor on the casing string. The method further includes pumping cement down the casing string and up an annulus to an expected height, the expected height being a vertical distance above the sensor, and detecting a presence or absence of cement with the sensor. If the sensor detects the presence of cement, the stage tool is kept closed and the packer is kept deflated. If the sensor detects the absence of cement, the stage tool is opened and the packer is inflated.

A method of removing dope from a tubing system in a wellbore includes the step of, prior to setting a production packer, reverse circulating fluid within a tubing-casing annulus (TCA) so that is flows from the tubing-casing annulus into a first tubing and propels at least one wiper plug within the first tubing in an uphole direction, thereby wiping the inside of the first tubing and removing excess dope.

A method of removing dope from a tubing system in a wellbore includes the step of, prior to setting a production packer, reverse circulating fluid within a tubing-casing annulus (TCA) so that is flows from the tubing-casing annulus into a first tubing and propels at least one wiper plug within the first tubing in an uphole direction, thereby wiping the inside of the first tubing and removing excess dope.

An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured tool body assembly having valving members (e.g., safety or kelly values) and valving members holding plugs, balls, or darts to be dropped. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation. An optional indicator indicates to a user or operator that a ball or plug has passed a selected one of the valving members. A transmitter (or transceiver) provides an ability to generate a wireless signal that is received by receivers (or transceivers) on the tool body assembly. Each receiver (or transceiver) controls an electrical actuator that engages a valving member or the indicator. Wireless signals can be used to open or close a valve or to reset a “tripped” indicator.

An improved method and apparatus for dropping a ball, plug or dart during oil and gas well operations (e.g., cementing operations) employs a specially configured tool body assembly having valving members (e.g., safety or kelly values) and valving members holding plugs, balls, or darts to be dropped. In one embodiment, the ball(s), dart(s) or plug(s) are contained in a sliding sleeve that shifts position responsive to valve rotation. An optional indicator indicates to a user or operator that a ball or plug has passed a selected one of the valving members. A transmitter (or transceiver) provides an ability to generate a wireless signal that is received by receivers (or transceivers) on the tool body assembly. Each receiver (or transceiver) controls an electrical actuator that engages a valving member or the indicator. Wireless signals can be used to open or close a valve or to reset a “tripped” indicator.

A method includes setting a tubular above a bottom of the well. The tubular having a float shoe attached to a distal end of the tubular and a controllable port penetrating a wall of the float shoe. The method further includes isolating a section of the annulus, opening the controllable port, and pumping cement through the controllable port into the section of the annulus to cement the annulus of the well.

A method includes setting a tubular above a bottom of the well. The tubular having a float shoe attached to a distal end of the tubular and a controllable port penetrating a wall of the float shoe. The method further includes isolating a section of the annulus, opening the controllable port, and pumping cement through the controllable port into the section of the annulus to cement the annulus of the well.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A nested drill bit assembly is disclosed for drilling a wellbore, comprising a parent bit and at least one child bit nested within the parent bit. Each bit in the nested drill bit assembly may be driven by a respective casing that gets cemented in place as part of a drilling with casing system. The parent bit and child bit(s) may be rotated together, with the parent bit and child bit collectively defining a contiguous cutting profile for drilling an initial segment of the wellbore. A driver is then lowered into the casing for connection to the child bit to drill beyond the parent bit. The driver may be configured as a drive bit for drilling through material leftover from a cementing operation prior to connecting to the child bit.

A nested drill bit assembly is disclosed for drilling a wellbore, comprising a parent bit and at least one child bit nested within the parent bit. Each bit in the nested drill bit assembly may be driven by a respective casing that gets cemented in place as part of a drilling with casing system. The parent bit and child bit(s) may be rotated together, with the parent bit and child bit collectively defining a contiguous cutting profile for drilling an initial segment of the wellbore. A driver is then lowered into the casing for connection to the child bit to drill beyond the parent bit. The driver may be configured as a drive bit for drilling through material leftover from a cementing operation prior to connecting to the child bit.