An internal blowout-prevention gas-retaining connector has a body mounted at the bottom of a drill pipe. The body includes a valve pipe section and a connecting pipe section arranged from top to bottom. The bottom of the valve pipe section is inserted into the top of the connecting pipe section. The blowout-prevention valve seat is provided at a bottom end of the valve pipe section while a blowout-prevention valve bonnet is provided on a bottom surface of the valve pipe section. The edge of the blowout-prevention valve bonnet is rotatably connected to a bottom surface edge of the valve pipe section. A torsion spring is provided on a bottom surface of the blowout-prevention valve bonnet. One end of the torsion spring is connected to the bottom surface of the blowout-prevention valve bonnet while the other end is connected to the inner wall of the connecting pipe section.

In one aspect, the present invention provides a plunger for use in a pumping system. The plunger can include a cylindrical plunger body that is adapted to be coupled to a drive rod. The plunger body can define an aperture configured to receive pumped fluids. The aperture can define an inner diameter of the plunger body. The plunger body can include a leading end having a tapered portion configured to direct solids into the aperture. The tapered portion can be tapered from the inner diameter toward an outer diameter of the plunger body to form a tip aligned with the outer diameter. The tapered portion can include two or more different degrees of taper along a length of the tapered portion. The plunger body can further include a rear end coupleable to a traveling valve.

In one aspect, the present invention provides a plunger for use in a pumping system. The plunger can include a cylindrical plunger body that is adapted to be coupled to a drive rod. The plunger body can define an aperture configured to receive pumped fluids. The aperture can define an inner diameter of the plunger body. The plunger body can include a leading end having a tapered portion configured to direct solids into the aperture. The tapered portion can be tapered from the inner diameter toward an outer diameter of the plunger body to form a tip aligned with the outer diameter. The tapered portion can include two or more different degrees of taper along a length of the tapered portion. The plunger body can further include a rear end coupleable to a traveling valve.

A downhole gravel packing apparatus, comprising: a tubular assembly for being arranged within a wellbore to define an annulus between said tubular assembly and a wall of the wellbore; and a control valve provided within the tubular assembly to control flow of a gravel pack carrier fluid between external and internal regions of the tubular assembly, the control valve comprising a fluid reactant arrangement which reacts with a first fluid to reconfigure the control valve from a first configuration in which flow through the control valve is permitted during a gravel packing operation, and a second configuration in which flow through the control valve is restricted.

A system including a first tubular with a first fluid passage configured to receive a fluid for use in a mineral extraction system, a second tubular surrounding the first tubular, a protective cover coupled to the second tubular with a shear pin, wherein the second tubular is configured to move the protective cover from a first axial position to a second axial position, and the protective cover is configured to form a first seal around the first fluid passage; and a retainer coupled to the first tubular or the protective cover and configured to couple the protective cover to the first tubular.

A system including a first tubular with a first fluid passage configured to receive a fluid for use in a mineral extraction system, a second tubular surrounding the first tubular, a protective cover coupled to the second tubular with a shear pin, wherein the second tubular is configured to move the protective cover from a first axial position to a second axial position, and the protective cover is configured to form a first seal around the first fluid passage; and a retainer coupled to the first tubular or the protective cover and configured to couple the protective cover to the first tubular.

A method can include directing fluid flow longitudinally through a well tool connected in a tubular string downstream of a longitudinally compressed circulating valve assembly, thereby causing the well tool to operate, and longitudinally elongating the circulating valve assembly while the fluid flow is ceased, and then increasing the fluid flow, thereby causing the fluid flow after the elongating to pass outwardly through a housing of the circulating valve assembly to an external annulus. Another method can include directing a fluid flow through a well tool connected in a tubular string downstream of a circulating valve assembly, thereby causing the well tool to operate, and decreasing then increasing a flow rate of the fluid flow, thereby causing the fluid flow to pass outwardly through a housing assembly of the circulating valve assembly to an external annulus. Circulating valve assemblies are also disclosed.

A system for heating a hydrocarbon resource in a subterranean formation having a wellbore extending therein may include a radio frequency (RF) source, a choke fluid source, and an elongate RF antenna configured to be positioned within the wellbore and coupled to the RF source, with the elongate RF antenna having a proximal end and a distal end separated from the proximal end. The system may also include a choke fluid dispenser coupled to the choke fluid source and positioned to selectively dispense choke fluid into adjacent portions of the subterranean formation at the proximal end of the RF antenna to define a common mode current choke at the proximal end of the RF antenna.

A system for heating a hydrocarbon resource in a subterranean formation having a wellbore extending therein may include a radio frequency (RF) source, a choke fluid source, and an elongate RF antenna configured to be positioned within the wellbore and coupled to the RF source, with the elongate RF antenna having a proximal end and a distal end separated from the proximal end. The system may also include a choke fluid dispenser coupled to the choke fluid source and positioned to selectively dispense choke fluid into adjacent portions of the subterranean formation at the proximal end of the RF antenna to define a common mode current choke at the proximal end of the RF antenna.

A shutoff valve device for permitting and preventing fluid flow in a production string. In one embodiments, the shutoff valve device comprising: a body comprising a borehole, wherein the body is a top sub coupled to a bottom sub via a threaded fastener; a flow tube disposed within the body's borehole and capable of axial movement within the body's borehole, comprising a flow tube borehole; a bi-directional actuator attached to a bottom opening of the flow tube, comprising flexible flaps; and a flapper valve disposed within the body's borehole, wherein the flapper valve is hingedly coupled to a top surface of the bottom sub and capable of moving between a fully opened and fully closed position.