# US 12,000,235 B2 · System and method for cementing a tubing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,000,235 B2 - Document ID: US12000235B2 - Status: Granted - Kind: B2 - Application number: 17/784,565 - Filed: 2021-01-07 - Published: 2023-01-05 - Granted: 2024-06-04 - Earliest claimed: 2020-01-08 - Assignees: National Oilwell DHT, L.P. - Applicants: National Oilwell DHT, L.P. - Inventors: Michael Rossing - Web page: https://patentgrep.com/patent/US12000235B2 ## CPC - E21B 33/13: Methods or devices for cementing, for plugging holes, crevices or the like - E21B 28/00: Vibration generating arrangements for boreholes or wells, e.g. for stimulating production ({for fishing for or freeing objects E21B31/005;} for transmitting measuring-signals E21B47/14; for geophysical measurements G01V1/02) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract At least one of pressure pulses, lateral oscillations, and axial oscillations can be generated by a distal downhole tool and a proximal downhole tool while cement is pumped into a well for cementing the well. Also, the generation of at least one of pressure pulses, lateral oscillations, and axial oscillations by the proximal downhole tool can continue even when the cement is no longer pumped around a tubing and is curing. In order to do so, a backflow path from a point downstream of the second vibration tool toward a wellhead is provided. Then a fluid, usually other than cement, is pumped from the wellhead, through the proximal downhole tool, and back into an annulus toward the wellhead. As such, a production tubing may remain centralized while the cement is curing. ## Claims ### Claim 1 A method of cementing a tubing, comprising: attaching a distal downhole tool in the tubing, the distal downhole tool including a first flow-through passage extending through the distal downhole tool and a first vibration tool; attaching a proximal downhole tool in the tubing, the proximal downhole tool including a second flow-through passage extending through the proximal downhole tool and a second vibration tool; generating at least one of pressure pulses, lateral oscillations, and axial oscillations with the second vibration tool by flowing cement in the second flow-through passage; generating at least one of pressure pulses, lateral oscillations, and axial oscillations with the first vibration tool by flowing the cement in the first flow-through passage; flowing cement around a portion of the tubing; providing a backflow path from a point downstream of the second vibration tool toward a wellhead; generating at least one of pressure pulses, lateral oscillations, and axial oscillations with the second vibration tool by flowing fluid other than the cement through the second flow-through passage while the cement is curing; and flowing the fluid in the backflow path. ### Claim 2 (depends on 1) The method of claim 1, wherein the backflow path from the point downstream of the second vibration tool toward the wellhead is provided with an annular space between the tubing and a casing surrounding the tubing, or an annular space between the tubing and a circulation means located inside the tubing. ### Claim 3 (depends on 1) The method of claim 1, wherein attaching the distal downhole tool in the tubing comprises extending an anchor including one or more slip-cone assemblies and causing the slips to grip against the tubing, or latching the distal downhole tool to a nipple profile forming a part of the tubing. ### Claim 4 (depends on 1) The method of claim 1, wherein attaching the proximal downhole tool in the tubing comprises extending an anchor including one or more slip-cone assemblies and causing the slips to grip against the tubing, or latching the proximal downhole tool to a nipple profile forming a part of the tubing. ### Claim 5 (depends on 1) The method of claim 1, further comprising preventing flow of cement between the distal downhole tool and the tubing using a packer included in the distal downhole tool. ### Claim 6 (depends on 1) The method of claim 1, further comprising applying a squeeze pressure to the cement while the cement is curing. ### Claim 7 (depends on 1) The method of claim 1, wherein the fluid includes Lost Circulation Material (LCM). ### Claim 8 A system for cementing a tubing, comprising: a distal downhole tool including means for attaching the distal downhole tool in the tubing, a first flow-through passage extending through the distal downhole tool, and a first vibration tool, wherein the first vibration tool is capable of generating at least one of pressure pulses, lateral oscillations, and axial oscillations by flowing cement in the first flow-through passage; a proximal downhole tool including means for attaching the proximal downhole tool in the tubing, a second flow-through passage extending through the proximal downhole tool, and a second vibration tool, wherein the second vibration tool is capable of generating at least one of pressure pulses, lateral oscillations, and axial oscillations by flowing the cement in the second flow-through passage and by flowing fluid other than the cement through the second flow-through passage while the cement is curing; and means for providing a backflow path from a point downstream of the second vibration tool toward a wellhead, wherein the means for providing the backflow path from the point downstream of the second vibration tool toward the wellhead includes an annular space between the tubing and a circulation means located inside the tubing. ### Claim 9 (depends on 8) The system of claim 8, wherein the means for providing the backflow path from the point downstream of the second vibration tool toward the wellhead includes a packer located near or at the wellhead, or an unloader valve connected to the second flow-through passage. ### Claim 10 (depends on 8) The system of claim 8, wherein the means for attaching the distal downhole tool in the tubing comprises an extendable anchor including one or more slip-cone assemblies, or a mechanism for latching the distal downhole tool to a nipple profile forming a part of the tubing. ### Claim 11 (depends on 8) The system of claim 8, wherein the means for attaching the proximal downhole tool in the tubing comprises an extendable anchor including one or more slip-cone assemblies, or a mechanism for latching the proximal downhole tool to a nipple profile forming a part of the tubing. ### Claim 12 (depends on 8) The system of claim 8, wherein the distal downhole tool further includes a packer capable of preventing flow of the cement between the distal downhole tool and the tubing. ### Claim 13 (depends on 8) The system of claim 8, wherein the first vibration tool and the second vibration tool each include at least one of a pressure-pulser and an agitator. ### Claim 14 (depends on 8) The system of claim 8, wherein the backflow path bypasses an annular space surrounding a lower portion of the tubing, whereby the cement in the annular space sets. ### Claim 15 A system for cementing a tubing, comprising: a distal downhole tool including means for attaching the distal downhole tool in the tubing, a first flow-through passage extending through the distal downhole tool, and a first vibration tool, wherein the first vibration tool is capable of generating at least one of pressure pulses, lateral oscillations, and axial oscillations by flowing cement in the first flow-through passage; a proximal downhole tool including means for attaching the proximal downhole tool in the tubing, a second flow-through passage extending through the proximal downhole tool, and a second vibration tool, wherein the second vibration tool is capable of generating at least one of pressure pulses, lateral oscillations, and axial oscillations by flowing the cement in the second flow-through passage and by flowing fluid other than the cement through the second flow-through passage while the cement is curing; and means for providing a backflow path from a point downstream of the second vibration tool toward a wellhead, wherein the backflow path bypasses an annular space surrounding a lower portion of the tubing, whereby the cement in the annular space sets, wherein the means for providing the backflow path from the point downstream of the second vibration tool toward the wellhead includes an annular space between the tubing and a casing surrounding the tubing. ### Claim 16 (depends on 15) The system of claim 15, wherein the means for providing the backflow path from the point downstream of the second vibration tool toward the wellhead includes a hole in the tubing, made at a location closer to the wellhead than a section to be cemented. ### Claim 17 (depends on 1, 2) The method of claim 1 or 2, wherein the backflow path passes through a hole in the tubing, a packer located near or at the wellhead, or an unloader valve connected to the second flow-through passage.