# US 10,865,607 B2 · Concentric pipe systems and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,607 B2 - Document ID: US10865607B2 - Status: Granted - Kind: B2 - Application number: 16/348,334 - Filed: 2017-11-08 - Published: 2019-09-12 - Granted: 2020-12-15 - Earliest claimed: 2016-11-08 - Assignees: Kryn Petroleum Services LLC - Applicants: Kryn Petroleum Services LLC - Inventors: Luc Deboer - Web page: https://patentgrep.com/patent/US10865607B2 ## CPC - E21B 21/001: {specially adapted for underwater drilling (dual gradient drilling E21B21/082)} - E21B 17/18: Pipes provided with plural fluid passages {(E21B17/203 takes precedence)} - E21B 17/20: Flexible or articulated drilling pipes {, e.g. flexible or articulated rods, pipes or cables} - E21B 21/103: {Down-hole by-pass valve arrangements, i.e. between the inside of the drill string and the annulus (valves specifically for maintaining circulation of drilling fluid while connecting or disconnecting tubular joints E21B21/019)} - E21B 21/12: using drilling pipes with plural fluid passages, e.g. closed circulation systems - E21B 2200/04: Ball valves - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## 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. ## Claims ### Claim 1 A well system, comprising: a surface system comprising an inlet conduit and a return conduit; a wellhead system disposed above a wellbore; a drill string extendable through the wellhead system into the wellbore and configured to circulate fluid from the surface system to the wellbore along an inlet fluid flowpath, and to circulate fluid from the wellbore to the surface system along a recirculation fluid flowpath, wherein the drill string comprises: a plurality of drill pipe joints, wherein each drill pipe joint comprises couplers disposed at ends thereof and a central passage; a first flow sub releasably coupled to at least one of the plurality of drill pipe joints, wherein the first flow sub comprises couplers disposed at each end thereof, a first receptacle disposed therein, and a second receptacle disposed therein; a first inner tubular member suspended from the first receptacle of the first flow sub, wherein the inner tubular member extends through the passage of at least one of the plurality of drill pipe joints forming an annulus therein that comprises at least a portion of the inlet flowpath; and a second inner tubular member slidingly received in the second receptacle whereby an outer surface of the second inner tubular member is unattached from an inner surface of the second receptacle, wherein the second inner tubular member comprises a seal assembly to sealingly engage the inner surface of the second receptacle. ### Claim 2 (depends on 1) The well system of claim 1, wherein the first flow sub comprises a bypass passage extending around the first receptacle and comprising a portion of the inlet flowpath. ### Claim 3 (depends on 1) The well system of claim 1, wherein the receptacle of the first flow sub is axially offset from each coupler of the first flow sub. ### Claim 4 (depends on 1) The well system of claim 1, wherein the drill string further comprises a circulation head comprising: a circulation body comprising a central passage, a receptacle disposed in the passage of the circulation body, and a radial port; and a swivel rotatably coupled to the circulation body and comprising an annular channel and a radial port, wherein the channel and radial port of the swivel are in fluid communication with the radial port of the circulation body for providing fluid communication between the inlet conduit of the surface system and the inlet flowpath of the drill string; wherein the second inner tubular member is suspended from the receptacle of the circulation body, wherein a passage of the second inner tubular member forms a portion of the recirculation flowpath. ### Claim 5 (depends on 4) The well system of claim 4, wherein the circulation head is disposed at the upper end of the drill string and is configured to receive torque from a top drive assembly to rotate the drill string. ### Claim 6 (depends on 4) The well system of claim 4, wherein the circulation body comprises a bypass passage extending around the receptacle disposed in the passage of the circulation body. ### Claim 7 (depends on 1) The well system of claim 1, wherein the drill string further comprises a concentric valve comprising: a valve body comprising a central passage, a receptacle disposed in the passage of the valve body and defining a chamber disposed therein, and a radial port extending between the receptacle of the valve body and an outer surface of the valve body to provide fluid communication between the chamber of the receptacle of the valve body and the surrounding environment; a second inner tubular member received in the receptacle of the valve body, wherein the inner tubular member comprises a seal assembly configured to sealingly engage an inner surface of the receptacle of the valve body; and a piston slidably disposed in the receptacle of the valve body, wherein the piston comprises a first position providing for fluid communication between the chamber of the valve body and the surrounding environment, and a second position restricting fluid communication between the surrounding environment and the chamber. ### Claim 8 (depends on 7) The well system of claim 7, further comprising a biasing member configured to bias the piston towards the second position. ### Claim 9 (depends on 7) The well system of claim 7, wherein the piston is configured to actuate into the first position in response to fluid pressure in the inlet flowpath being greater than fluid pressure in the recirculation flowpath. ### Claim 10 (depends on 7) The well system of claim 7, wherein the valve body comprises a bypass passage extending around the receptacle of the valve body and circumferentially spaced from the radial port, wherein the bypass passage comprises a portion of the inlet flowpath. ### Claim 11 A tubular assembly for a well system, comprising: a drill pipe joint comprising 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 comprises a second pair of couplers disposed at each end thereof, a first receptacle disposed therein and a second 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; a second inner tubular member slidingly received in the second receptacle whereby an outer surface of the second inner tubular member is unattached from an inner surface of the second receptacle wherein the second inner tubular member comprises a seal assembly to sealingly engage the inner surface of the second receptacle. ### Claim 12 (depends on 11) The tubular assembly of claim 11, wherein the flow sub comprises a bypass passage extending around the first receptacle. ### Claim 13 (depends on 11) The tubular assembly of claim 11, wherein the receptacle of the flow sub is axially offset from each of the second pair of couplers. ### Claim 14 (depends on 11) The tubular assembly of claim 11, further comprising a circulation head comprising: a circulation body comprising a central passage, a receptacle disposed in the passage of the circulation body, and a radial port; and a swivel rotatably coupled to the circulation body and comprising an annular channel and a radial port, wherein the channel and radial port of the swivel are in fluid communication with the radial port of the circulation body; wherein the second inner tubular member is configured to be suspended from the receptacle of the circulation body. ### Claim 15 A method for drilling a wellbore, comprising: (a) coupling a drill pipe joint with a flow sub; (b) suspending a first inner tubular member from a first receptacle of the flow sub through a passage of the drill pipe joint; (c) slidingly receiving a second inner tubular member in a second receptacle of the flow sub whereby an outer surface of the second inner tubular member is unattached from an inner surface of the second receptacle, wherein the second inner tubular member comprises a seal assembly to sealingly engage the inner surface of the second receptacle; and (d) circulating drilling fluid through a passage of the first inner tubular member and a bypass passage of the flow sub that extends around the first receptacle. ### Claim 16 (depends on 15) The method of claim 15, further comprising: (e) coupling a circulation head including a swivel to the drill pipe joint; and (f) suspending the second inner tubular member from a receptacle of the circulation head.