# US 2013/0153296 A1 · Systems and Methods to Inhibit Packoff Formation During Drilling Assembly Removal from a Wellbore > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153296 A1 - Document ID: US20130153296A1 - Status: Published application - Kind: A1 - Application number: 13/717,164 - Filed: 2012-12-17 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: ExxonMobil Upstream Research Company - Inventors: Chinar R. Aphale; Pietro Valsecchi; Jon M. Wallace; Fuping Zhou - Web page: https://patentgrep.com/patent/US20130153296A1 ## CPC - E21B 31/03: Freeing by flushing - E21B 21/00: Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) - E21B 21/10: Valve arrangements in drilling-fluid circulation systems - E21B 23/04: operated by fluid means, e.g. actuated by explosion (E21B23/08 takes precedence) - E21B 41/0078: {Nozzles used in boreholes (drilling by liquid or gas jets E21B7/18; drill bits with nozzles E21B10/60; perforators using direct fluid action E21B43/114; obtaining a slurry of minerals using nozzles E21B43/29)} - E21B 31/107: using impact means for releasing stuck parts, e.g. jars - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Systems and methods to inhibit packoff during drilling assembly removal from a wellbore, utilizing a drilling assembly that includes a transition region between a first section having a first cross-sectional area and a second section having a second cross-sectional area, wherein the second cross-sectional area is greater than the first cross-sectional area. The transition region includes a fluidizing assembly configured to partially fluidize a portion of the cuttings bed that is proximal to the transition region, and/or be in fluid communication with a flow control assembly configured to control flow rate of a fluidizing stream from the fluidizing assembly and to the portion of cuttings bed. ## Claims ### Claim 1 A drilling assembly configured to drill a wellbore, the drilling assembly comprising: a first section having a first cross-sectional area; a second section having a second cross-sectional area, wherein the first cross-sectional area is less than the second cross-sectional area, and further wherein the first section is farther from a terminal end of the drilling assembly than the second section; a fluid conduit, wherein the first section and the second section define at least a portion of the fluid conduit, and further wherein the fluid conduit is configured to transmit a drilling fluid stream to the terminal end of the drilling assembly; a transition region between the first section and the second section; a fluidizing assembly configured to fluidize a portion of a cuttings bed proximal the transition region; and a flow control assembly configured to selectively divert a portion of the drilling fluid stream to the fluidizing assembly, wherein the fluidizing assembly is configured to provide the portion of the drilling fluid stream to the portion of the cuttings bed as a fluidizing stream. ### Claim 2 (depends on 1) The drilling assembly of claim 1, wherein a ratio of the second cross-sectional area to the first cross-sectional area is at least 1.1:1. ### Claim 3 (depends on 1) The drilling assembly of claim 1, wherein the fluidizing stream includes 1 to 60% of the drilling fluid stream. ### Claim 4 (depends on 1) The drilling assembly of claim 1, wherein the fluidizing assembly is configured to provide the fluidizing stream when the drilling assembly is being removed from the wellbore. ### Claim 5 (depends on 1) The drilling assembly of claim 1, wherein the drilling assembly is configured to selectively control an orientation of at least a portion of the fluidizing assembly to selectively provide the fluidizing stream to the portion of the cuttings bed. ### Claim 6 (depends on 1) The drilling assembly of claim 1, wherein the portion of the cuttings bed includes a portion of the cuttings bed that is within 0.5 meters of the transition region. ### Claim 7 (depends on 1) The drilling assembly of claim 1, wherein the fluidizing assembly includes at least one of a fluid orifice and a diffuser configured to provide the fluidizing stream. ### Claim 8 (depends on 7) The drilling assembly of claim 7, wherein the fluidizing assembly includes a plurality of fluid orifices. ### Claim 9 (depends on 7) The drilling assembly of claim 7, wherein the fluid orifice includes an inner diameter of 1-3 cm. ### Claim 10 (depends on 7) The drilling assembly of claim 7, wherein a pressure drop across the fluid orifice is less than 25% of a pressure of the drilling fluid stream within the transition region. ### Claim 11 (depends on 1) The drilling assembly of claim 1, wherein the transition region is at least 5 meters from the terminal end of the drilling assembly. ### Claim 12 (depends on 1) A drill rig, comprising: the drilling assembly of claim 1; a mechanical drive assembly in mechanical communication with the drilling assembly; a fluid supply assembly in fluid communication with the drilling assembly and configured to supply the drilling fluid stream to the drilling assembly; and a controller configured to control the operation of the drill rig. ### Claim 13 (depends on 12) The drill rig of claim 12, wherein the controller is configured to increase the portion of the drilling fluid stream that is supplied to the fluidizing assembly responsive to detecting at least one of a hook load that is greater than a maximum hook load threshold, a wellbore pressure that is greater than a maximum wellbore pressure threshold, and a wellbore diameter proximal to the fluidizing assembly that is greater than a maximum threshold wellbore diameter, and further wherein the controller is configured to decrease the portion of the drilling fluid stream that is supplied to the fluidizing assembly responsive to detecting at least one of a hook load that is less than a minimum hook load threshold, a wellbore pressure that is less than a minimum wellbore pressure threshold, and a wellbore diameter proximal to the fluidizing assembly that is less than a minimum threshold wellbore diameter. ### Claim 14 (depends on 12) The drill rig of claim 12, wherein the controller that is configured to control the operation of the flow control assembly based, at least in part, on a hydraulics model of at least a portion of the wellbore. ### Claim 15 A method of removing a drilling assembly from a wellbore, wherein the drilling assembly includes a transition region between a first section including a first cross-sectional area and a second section including a second cross-sectional area, wherein the first cross-sectional area is less than the second cross-sectional area, wherein the first section is farther from a terminal end of the drilling assembly than the second section, and further wherein the drilling assembly includes a fluid conduit configured to transmit a drilling fluid stream, the method comprising: withdrawing at least a portion of the drilling assembly from the wellbore; detecting a variable associated with packoff within the wellbore; and providing a fluidizing stream to a portion of a cuttings bed proximal the transition region, wherein the fluidizing stream includes a portion of the drilling fluid stream, and further wherein the providing includes selectively providing the fluidizing stream based at least in part on the variable associated with packoff. ### Claim 16 (depends on 15) The method of claim 15, wherein the variable associated with packoff includes at least one of a hook load, a down-hole pressure, a surface pressure, a down-hole torque, a surface torque, a fraction of the drilling fluid stream that comprises the fluidizing stream, an average diameter of the wellbore, a diameter of a portion of the wellbore, a diameter of a portion of the wellbore that is proximal to the transition region, the first cross-sectional area, the second cross-sectional area, an orientation of the wellbore, and an orientation of a portion of the wellbore that is proximal to the transition region. ### Claim 17 (depends on 15) The method of claim 15, wherein the selectively providing includes controlling a flow rate of the fluidizing stream. ### Claim 18 (depends on 15) The method of claim 15, wherein the selectively providing includes selectively providing 1 to 60% of the drilling fluid stream as the fluidizing stream. ### Claim 19 (depends on 15) The method of claim 15, wherein the selectively providing includes increasing a flow rate of the fluidizing stream responsive to detecting at least one of a hook load that is greater than a maximum hook load threshold, a wellbore pressure that is greater than a maximum wellbore pressure, a torque that is greater than a maximum torque, and a wellbore diameter proximal to the transition region that is greater than a maximum threshold wellbore diameter, and further wherein the selectively providing includes decreasing the flow rate of the fluidizing stream responsive to detecting at least one of a hook load that is less than a minimum hook load threshold, a wellbore pressure that is less than a minimum wellbore pressure, and a wellbore diameter proximal to the transition region that is less than a minimum threshold wellbore diameter. ### Claim 20 (depends on 15) The method of claim 15, wherein the providing includes selectively providing the fluidizing stream based at least in part on a variable associated with the drilling assembly, wherein the variable associated with the drilling assembly includes at least one of an orientation of the drilling assembly within the wellbore, an orientation of a fluidizing assembly within the wellbore, and a distance between the transition region and the portion of the cuttings bed. ### Claim 21 (depends on 15) The method of claim 15, wherein the drilling assembly includes a fluidizing assembly that includes a plurality of fluid orifices, and further wherein the providing includes selectively providing the fluidizing stream to a selected one of the plurality of fluid orifices responsive at least in part to at least one of an orientation of the selected one of the plurality of fluid orifices and a location of the selected one of the plurality of fluid orifices with respect to a location of the portion of the cuttings bed. ### Claim 22 (depends on 21) The method of claim 21, wherein the method includes providing the fluidizing stream to the selected one of the plurality of fluid orifices responsive to the selected one of the plurality of fluid orifices being within a threshold distance of the portion of the cuttings bed. ### Claim 23 (depends on 21) The method of claim 21, wherein the drilling assembly includes an orientation detection device configured to detect an orientation of each of the plurality of fluid orifices, wherein the method further includes detecting the orientation of each of the plurality of fluid orifices, and further wherein the method includes providing the fluidizing stream to the selected one of the plurality of fluid orifices responsive to detecting that the selected one of the plurality of fluid orifices is within a threshold distance of a bottom surface of the wellbore. ### Claim 24 (depends on 21) The method of claim 21, wherein the selected one of the plurality of fluid orifices includes an orientation control assembly configured to control an orientation of the selected one of the plurality of orifices with respect to at least one of the drilling assembly, the wellbore, and the cuttings bed, and further wherein the method includes controlling the orientation of the selected one of the plurality of fluid orifices, wherein the controlling includes directing a portion of the fluidizing stream that flows through the selected one of the plurality of fluid orifices toward the cuttings bed. ### Claim 25 (depends on 21) The method of claim 21, wherein the selectively providing includes selectively providing the fluidizing stream to a base of the cuttings bed. ### Claim 26 (depends on 21) The method of claim 21, wherein at least a portion of the plurality of fluid orifices includes a diffuser. ### Claim 27 (depends on 15) The method of claim 15, wherein the method further includes modeling the drilling assembly as it is removed from the wellbore, wherein the modeling includes calculating a target portion of the drilling fluid stream that comprises the fluidizing stream, and further wherein the providing includes selectively providing the fluidizing stream responsive at least in part on at least one of the modeling and the calculating. ### Claim 28 (depends on 27) The method of claim 27, wherein the modeling is based at least in part on at least one of a variable associated with the wellbore, an average diameter of the wellbore, a diameter of a portion of the wellbore, a length of the wellbore, an orientation of the wellbore, a composition of a geological formation that contains the wellbore, a composition of the cuttings bed, a variable associated with the drilling assembly, a diameter of the drilling assembly, the first cross-sectional area, the second cross-sectional area, a diameter of a bottom-hole assembly associated with the drilling assembly, a cuttings bed height, a variable associated with the drilling fluid stream, a viscosity of the drilling fluid, and a variable associated with a drill rig. ### Claim 29 (depends on 15) The method of claim 15, wherein the method further includes injecting a packoff-inhibiting additive into the drilling fluid stream. ### Claim 30 (depends on 15) The method of claim 15, wherein the providing includes providing the fluidizing stream at a fluidizing stream pressure that is within 25% of a pressure of the drilling fluid stream within the transition region. ### Claim 31 A drilling assembly configured to drill a wellbore, the drilling assembly comprising: a first section having a first cross-sectional area; a second section having a second cross-sectional area, wherein the first cross-sectional area is less than the second cross-sectional area, and further wherein the first section is farther from a terminal end of the drilling assembly than the second section; a transition region between the first section and the second section; a fluidizing assembly configured to fluidize a portion of a cuttings bed proximal the transition region; and a fluid drive assembly configured to receive a wellbore fluid stream from within the wellbore and to provide the wellbore fluid stream to the fluidizing assembly, wherein the fluidizing assembly is configured to provide the wellbore fluid stream to the portion of the cuttings bed as a fluidizing stream. ### Claim 32 A method of removing a drilling assembly from a wellbore, wherein the drilling assembly includes a transition region between a first section including a first cross-sectional area and a second section including a second cross-sectional area, wherein the first cross-sectional area is less than the second cross-sectional area, and further wherein the first section is farther from a terminal end of the drilling assembly than the second section, the method comprising: withdrawing at least a portion of the drilling assembly from the wellbore; detecting a variable associated with packoff within the wellbore; and providing a fluidizing stream to a portion of a cuttings bed proximal the transition region, wherein the fluidizing stream includes a wellbore fluid stream that is received into the drilling assembly from within the wellbore, and further wherein the providing includes selectively providing the fluidizing stream based at least in part on the variable associated with packoff.