Abstract: A radio frequency (RF) antenna assembly configured to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery may include an RF transmission line and an RF antenna coupled to the RF transmission line. The RF antenna assembly may also include an adjustable balun that may include a tubular balun housing surrounding the RF transmission line and defining a space therebetween. The adjustable balun may further include an adjustable shorting body slidably movable within the space and contacting the tubular balun housing and the RF transmission line at an adjustable shorting position.

Abstract: A transmission line segment coupler is for coupling together first and second coaxial transmission line segments each including an inner tubular conductor and an outer tubular conductor surrounding the inner tubular conductor and a dielectric therebetween. The coupler apparatus includes an outer tubular bearing body to be positioned within adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments, and an inner tubular bearing body configured to slidably move within the outer tubular bearing body to define a linear bearing therewith. The inner tubular bearing body is configured to define a fluid passageway in communication with the adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments.

Abstract: An antenna assembly may be positioned within a wellbore in a subterranean formation. The antenna assembly includes a tubular antenna element to be positioned within the wellbore, and an RF coaxial transmission line to be positioned within the tubular antenna element. The RF coaxial transmission line includes a series of coaxial sections coupled together in end-to-end relation, each coaxial section including an inner conductor, an outer conductor surrounding the inner conductor, and a dielectric therebetween. Each of the outer conductors has opposing threaded ends defining overlapping mechanical threaded joints with adjacent outer conductors.

Abstract: A transmission line segment coupler is for coupling together first and second coaxial transmission line segments each including an inner tubular conductor and an outer tubular conductor surrounding the inner tubular conductor and a dielectric therebetween. The coupler apparatus includes an outer tubular bearing body to be positioned within adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments, and an inner tubular bearing body configured to slidably move within the outer tubular bearing body to define a linear bearing therewith. The inner tubular bearing body is configured to define a fluid passageway in communication with the adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments.

Abstract: A radio frequency (RF) coaxial transmission line to be positioned within a wellbore in a subterranean formation may include a series of coaxial sections coupled together in end-to-end relation. Each coaxial section may include an inner conductor, a dual-wall outer conductor surrounding the inner conductor, and a dielectric therebetween. Each of the dual-wall outer conductors may include an outer wall and an inner wall spaced apart therefrom defining a fluid passageway. Each coaxial section may further include a threaded endpiece coupled to each opposing end of the dual-wall outer conductor and having threads to define an overlapping mechanical threaded joint and an electrical joint with an adjacent threaded endpiece.

Abstract: A transmission line segment coupler is for coupling together first and second coaxial transmission line segments each including an inner tubular conductor and an outer tubular conductor surrounding the inner tubular conductor and a dielectric therebetween. The coupler apparatus includes an outer tubular bearing body to be positioned within adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments, and an inner tubular bearing body configured to slidably move within the outer tubular bearing body to define a linear bearing therewith. The inner tubular bearing body is configured to define a fluid passageway in communication with the adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments.

Abstract: A radio frequency (RF) antenna assembly configured to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery may include an RF transmission line and an RF antenna coupled to the RF transmission line. The RF antenna assembly may also include an adjustable balun that may include a tubular balun housing surrounding the RF transmission line and defining a space therebetween. The adjustable balun may further include an adjustable shorting body slidably movable within the space and contacting the tubular balun housing and the RF transmission line at an adjustable shorting position.

Abstract: An RF antenna assembly is positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes first and second tubular conductors to be positioned within the wellbore, and having adjacent joined together ends, and first and second RF transmission line segments extending within the first and second tubular conductors and having adjacent joined together ends aligned with the joined together adjacent ends of the first and second tubular conductors. The RF antenna assembly includes a tubular sheath surrounding the first RF transmission line segment and having an outer surface, and a spacer received on the outer surface of the tubular sheath and extending between the tubular sheath and adjacent portions of the first tubular conductor.

Abstract: A rigid RF coaxial transmission line is positioned within a wellbore in a subterranean formation. The rigid RF coaxial transmission line includes a series of rigid coaxial sections coupled together in end-to-end relation and to be positioned within the wellbore of the subterranean formation. Each rigid coaxial section includes an inner conductor, a rigid outer conductor surrounding the inner conductor, and a dielectric therebetween. Each of the rigid outer conductors has threaded ends. The rigid RF coaxial transmission line includes a respective connector between adjacent ones of the series of rigid coaxial sections, each connector having a rigid outer layer threadingly secured to respective threaded ends of adjacent rigid outer conductors, and an electrically conductive liner carried by the rigid outer layer and defining an electrical joint between the adjacent rigid outer conductors.

Abstract: An RF antenna assembly is positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes first and second tubular conductors and a dielectric isolator therebetween. The dielectric isolator includes a dielectric tube having opposing first and second open ends, a first tubular connector having a first slotted recess receiving therein the first open end of the dielectric tube, and a second tubular connector having a second slotted recess receiving therein the second open end of the dielectric tube.

Abstract: A radio frequency (RF) antenna assembly configured to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery may include an RF transmission line and an RF antenna coupled to the RF transmission line. The RF antenna assembly may also include an adjustable balun that may include a tubular balun housing surrounding the RF transmission line and defining a space therebetween. The adjustable balun may further include an adjustable shorting body slidably movable within the space and contacting the tubular balun housing and the RF transmission line at an adjustable shorting position.

Abstract: An RF antenna assembly is to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes a series of tubular dipole antennas to be positioned within the wellbore, each tubular dipole antenna having a pair of dipole elements, and an RF transmission line extending within the series of tubular dipole antennas. The RF antenna assembly includes a respective coupling structure between each pair of dipole elements and between the series of tubular dipole antennas, each coupling structure including a dielectric tube mechanically coupling adjacent dipole elements, and a tap connector carried by the dielectric tube and electrically coupling the RF transmission line to a corresponding dipole element.

Abstract: An RF antenna assembly is positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes first and second tubular conductors to be positioned within the wellbore, and having adjacent joined together ends, and first and second RF transmission line segments extending within the first and second tubular conductors and having adjacent joined together ends aligned with the joined together adjacent ends of the first and second tubular conductors. The RF antenna assembly includes a tubular sheath surrounding the first RF transmission line segment and having an outer surface, and a spacer received on the outer surface of the tubular sheath and extending between the tubular sheath and adjacent portions of the first tubular conductor.

Abstract: A rigid RF coaxial transmission line is positioned within a wellbore in a subterranean formation. The rigid RF coaxial transmission line includes a series of rigid coaxial sections coupled together in end-to-end relation and to be positioned within the wellbore of the subterranean formation. Each rigid coaxial section includes an inner conductor, a rigid outer conductor surrounding the inner conductor, and a dielectric therebetween. Each of the rigid outer conductors has threaded ends. The rigid RF coaxial transmission line includes a respective connector between adjacent ones of the series of rigid coaxial sections, each connector having a rigid outer layer threadingly secured to respective threaded ends of adjacent rigid outer conductors, and an electrically conductive liner carried by the rigid outer layer and defining an electrical joint between the adjacent rigid outer conductors.

Abstract: A radio frequency (RF) applicator may be rotated during positioning within a wellbore in a subterranean formation. The wellbore may have at least one bend therein. The RF applicator may include a series of tubular conductors, and a respective bendable tubular dielectric coupler rotationally interlocking opposing ends of adjacent ones of the series of tubular conductors to define a tubular antenna. The RF applicator may include at least one RF feed conductor extending within the tubular antenna and connected to the series of tubular conductors.

Abstract: A rigid radio frequency (RF) coaxial transmission line to be positioned within a wellbore in a subterranean formation may include a series of rigid coaxial sections coupled together in end-to-end relation. Each rigid coaxial section may include an inner conductor, a rigid outer conductor surrounding the inner conductor, and a dielectric therebetween. Each of the rigid outer conductors may include a rigid outer layer having opposing threaded ends defining overlapping mechanical threaded joints with adjacent rigid outer layers. Each of the rigid outer conductors may also include an electrically conductive inner layer coupled to the rigid outer layer and having opposing ends defining electrical joints with adjacent electrically conductive inner layers.

Abstract: An RF antenna assembly is positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes first and second tubular conductors and a dielectric isolator therebetween. The dielectric isolator includes a dielectric tube having opposing first and second open ends, a first tubular connector having a first slotted recess receiving therein the first open end of the dielectric tube, and a second tubular connector having a second slotted recess receiving therein the second open end of the dielectric tube.

Abstract: An RF antenna assembly is to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery. The RF antenna assembly includes a series of tubular dipole antennas to be positioned within the wellbore, each tubular dipole antenna having a pair of dipole elements, and an RF transmission line extending within the series of tubular dipole antennas. The RF antenna assembly includes a respective coupling structure between each pair of dipole elements and between the series of tubular dipole antennas, each coupling structure including a dielectric tube mechanically coupling adjacent dipole elements, and a tap connector carried by the dielectric tube and electrically coupling the RF transmission line to a corresponding dipole element.

Abstract: A radio frequency (RF) antenna assembly configured to be positioned within a wellbore in a subterranean formation for hydrocarbon resource recovery may include an RF transmission line and an RF antenna coupled to the RF transmission line. The RF antenna assembly may also include an adjustable balun that may include a tubular balun housing surrounding the RF transmission line and defining a space therebetween. The adjustable balun may further include an adjustable shorting body slidably movable within the space and contacting the tubular balun housing and the RF transmission line at an adjustable shorting position.

Abstract: A transmission line segment coupler is for coupling together first and second coaxial transmission line segments each including an inner tubular conductor and an outer tubular conductor surrounding the inner tubular conductor and a dielectric therebetween. The coupler apparatus includes an outer tubular bearing body to be positioned within adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments, and an inner tubular bearing body configured to slidably move within the outer tubular bearing body to define a linear bearing therewith. The inner tubular bearing body is configured to define a fluid passageway in communication with the adjacent open ends of the inner tubular conductors of the first and second coaxial transmission line segments.