Abstract: A concentric valve positionable in a wellbore includes a valve body including an outer surface and a central passage, a receptacle disposed in the central passage and defining a chamber disposed therein, and a radial port extending between the receptacle and the outer surface to provide fluid communication between the chamber of the receptacle and an environment surrounding the concentric valve, an inner tubular member received in the receptacle of the valve body, wherein the inner tubular member includes a seal assembly configured to sealingly engage an inner surface of the receptacle, and a bypass passage extending around the receptacle of the valve body and circumferentially spaced from the radial port, wherein the bypass passage provides fluid communication between a first end of the central passage and a second end of the central passage opposite the first end.

Abstract: A well system includes a drilling vessel, a concentric drillstring extending from the vessel into a subterranean wellbore disposed beneath a mudline, wherein the concentric drillstring is configured to circulate a drilling fluid from the drilling vessel into the wellbore along a first passage, and to circulate the drilling fluid from the wellbore to the drilling vessel along a second passage, and a subsea pump in fluid communication with the wellbore, wherein the subsea pump is configured to manage fluid pressure in the wellbore by controlling a height of a column of hydrostatic fluid disposed in the wellbore.

Abstract: A concentric valve positionable in a wellbore includes a valve body including an outer surface and a central passage, a receptacle disposed in the central passage and defining a chamber disposed therein, and a radial port extending between the receptacle and the outer surface to provide fluid communication between the chamber of the receptacle and an environment surrounding the concentric valve, an inner tubular member received in the receptacle of the valve body, wherein the inner tubular member includes a seal assembly configured to sealingly engage an inner surface of the receptacle, and a bypass passage extending around the receptacle of the valve body and circumferentially spaced from the radial port, wherein the bypass passage provides fluid communication between a first end of the central passage and a second end of the central passage opposite the first end.

Abstract: A tubular assembly for a well system includes a drill pipe joint including a first pair of couplers disposed at ends thereof and a central passage, a flow sub configured to couple with the drill pipe joint, wherein the flow sub includes a second pair of couplers disposed at each end thereof and a first receptacle disposed therein, a first inner tubular member configured to be suspended from the first receptacle of the flow sub, wherein the first inner tubular member extends through the passage of the drill pipe joint forming an annulus therein when the drill pipe joint is coupled to the flow sub and the first inner tubular member is suspended from the first receptacle of the flow sub.

Abstract: A tubular assembly for a well system includes a drill pipe joint including a first pair of couplers disposed at ends thereof and a central passage, a flow sub configured to couple with the drill pipe joint, wherein the flow sub includes a second pair of couplers disposed at each end thereof and a first receptacle disposed therein, a first inner tubular member configured to be suspended from the first receptacle of the flow sub, wherein the first inner tubular member extends through the passage of the drill pipe joint forming an annulus therein when the drill pipe joint is coupled to the flow sub and the first inner tubular member is suspended from the first receptacle of the flow sub.