Abstract: A technique facilitates on-demand release of desired sections of a well string, e.g. sections of a perforating gun string, via at least one on-demand release tool. The on-demand release tool has an activation mechanism which may be selectively actuated to transition the on-demand release tool from a first loadbearing configuration to a second loadbearing configuration. The on-demand release tool may then be transitioned to a release stage which allows a first section of the on-demand release tool to be separated from a second section of the on-demand release tool by activating a release mechanism. In at least some applications, the on-demand release tool also comprises a ballistic transfer device to enable reliable ballistic transfer between sections of the perforating gun string.

Abstract: A method for drilling a wellbore includes drilling the wellbore by advancing the tubular string longitudinally into the wellbore; stopping drilling by holding the tubular string longitudinally stationary; adding a tubular joint or stand of joints to the tubular string while injecting drilling fluid into a side port of the tubular string, rotating the tubular string, and holding the tubular string longitudinally stationary; and resuming drilling of the wellbore after adding the joint or stand.

Abstract: A method for drilling a wellbore includes drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit. The tubular string includes: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore. The method further includes moving the sleeve to the open position; and injecting drilling fluid into the port at a second flow rate while adding a tubular joint(s) to the tubular string. The injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint(s).

Abstract: A technique facilitates on-demand release of desired sections of a well string, e.g. sections of a perforating gun string, via at least one on-demand release tool. The on-demand release tool has an activation mechanism which may be selectively actuated to transition the on-demand release tool from a first loadbearing configuration to a second loadbearing configuration. The on-demand release tool may then be transitioned to a release stage which allows a first section of the on-demand release tool to be separated from a second section of the on-demand release tool by activating a release mechanism. In at least some applications, the on-demand release tool also comprises a ballistic transfer device to enable reliable ballistic transfer between sections of the perforating gun string.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member, such as a flapper, that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member, such as a flapper, that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member, such as a flapper, that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: A method for drilling a wellbore includes drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit. The tubular string includes: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore. The method further includes moving the sleeve to the open position; and injecting drilling fluid into the port at a second flow rate while adding a tubular joint(s) to the tubular string. The injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint(s).

Abstract: A method for drilling a wellbore includes drilling the wellbore by advancing the tubular string longitudinally into the wellbore; stopping drilling by holding the tubular string longitudinally stationary; adding a tubular joint or stand of joints to the tubular string while injecting drilling fluid into a side port of the tubular string, rotating the tubular string, and holding the tubular string longitudinally stationary; and resuming drilling of the wellbore after adding the joint or stand.

Abstract: A method for drilling a wellbore includes drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit. The tubular string includes: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore. The method further includes moving the sleeve to the open position; and injecting drilling fluid into the port at a second flow rate while adding a tubular joint(s) to the tubular string. The injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint(s).

Abstract: A method for drilling a wellbore includes drilling the wellbore by advancing the tubular string longitudinally into the wellbore; stopping drilling by holding the tubular string longitudinally stationary; adding a tubular joint or stand of joints to the tubular string while injecting drilling fluid into a side port of the tubular string, rotating the tubular string, and holding the tubular string longitudinally stationary; and resuming drilling of the wellbore after adding the joint or stand.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member, such as a flapper, that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: Methods and apparatus enable reliable and improved isolation between two portions of a bore extending through a casing string disposed in a borehole. A downhole deployment valve (DDV) may provide the isolation utilizing a valve member such as a flapper that is disposed in a housing of the DDV and is designed to close against a seat within the housing. The DDV includes an operating mechanism for opening/closing the DDV. In use, pressure in one portion of a well that is in fluid communication with a well surface may be bled off and open at well surface while maintaining pressure in another portion of the casing string beyond the DDV.

Abstract: A method for drilling a wellbore includes drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit. The tubular string includes: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore. The method further includes moving the sleeve to the open position; and injecting drilling fluid into the port at a second flow rate while adding a tubular joint(s) to the tubular string. The injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint(s).