# US 11,441,379 B2 · Downhole tool with a propellant charge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,379 B2 - Document ID: US11441379B2 - Status: Granted - Kind: B2 - Application number: 16/998,373 - Filed: 2020-08-20 - Published: 2020-12-03 - Granted: 2022-09-13 - Earliest claimed: 2015-04-13 - Assignees: Spex Corporate Holdings Limited - Applicants: Spex Corporate Holdings Ltd. - Inventors: Rae Younger - Web page: https://patentgrep.com/patent/US11441379B2 ## CPC - E21B 29/02: by explosives or by thermal or chemical means {(freeing stuck objects by explosives E21B31/002)} - E21B 7/04: Directional drilling - E21B 23/04: operated by fluid means, e.g. actuated by explosion (E21B23/08 takes precedence) - E21B 23/0414: {using explosives} - E21B 29/06: Cutting windows, e.g. directional window cutters for whipstock operations ({E21B29/005 and} E21B29/08 take precedence) - E21B 31/002: {Destroying the objects to be fished, e.g. by explosive means} - E21B 37/00: Methods or apparatus for cleaning boreholes or wells (E21B21/00 takes precedence) - E21B 37/08: cleaning in situ of down-hole filters, screens, {e.g. casing perforations,} or gravel packs (E21B37/06 takes precedence) - E21B 41/0085: {Adaptations of electric power generating means for use in boreholes} - E21B 43/105: {Expanding tools specially adapted therefor} - E21B 43/263: using explosives - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A method of removing material from a target is described. The method comprises the steps of providing a tool, the tool having at least one propellant source; pressurising the tool to a pressure higher than the environmental pressure; igniting at least one of the propellant source(s) to form a combustion zone; and directing combustion products generated at the combustion zone along at least one tool flow path. The tool flow path(s) is selectively openable or closable, such that upon exiting the tool flow path(s) the combustion products interact with a target, the interaction causing material to be removed from the target. ## Claims ### Claim 1 A tool for initiating a change in a target, the tool comprising: at least one propellant source, at least one additive, at least one mechanism for igniting the propellant source(s), and at least one flow path, wherein, upon ignition, at least one of the/each propellant source(s) combusts to release combustion products which, in use, flow out of the tool along the flow path towards a target to be changed, the combustion products containing the additive(s), the additive(s) on contact with the target acting as a plugging material, a metal repair material, an activation material, a dissolving agent, a gelling agent, a chemical tracer, and/or a radioactive material. ### Claim 2 (depends on 1) The tool of claim 1, wherein the combustion products create a chemical reaction in the target. ### Claim 3 (depends on 1) The tool of claim 1, wherein the flow path defines a flow path profile, the flow path profile being configured to create a change in a combustion product parameter. ### Claim 4 (depends on 3) The tool of claim 3, wherein the flow path is configured to change the pressure, temperature and/or speed of the combustion products. ### Claim 5 (depends on 1) The tool of claim 1, wherein there are multiple flow paths. ### Claim 6 (depends on 5) The tool of claim 5, wherein, where there are multiple flow paths, at least some of the flow paths converge into a single flow path. ### Claim 7 (depends on 1) The tool of claim 1, wherein, where there is a single flow path, the single flow path diverges into multiple flow paths. ### Claim 8 (depends on 1) The tool of claim 1, wherein the flow path(s) has a variable cross-section. ### Claim 9 (depends on 1) The tool of claim 1, wherein the flow path(s) includes one or more restrictions. ### Claim 10 (depends on 9) The tool of claim 9, wherein the restriction(s) are movable with respect to the flow path(s) to create combustion products pulses. ### Claim 11 (depends on 9) The tool of claim 9, wherein the restriction(s) define a reduced flow path(s) cross section. ### Claim 12 (depends on 9) The tool of claim 9, wherein the restriction(s) define a varying flow path cross section. ### Claim 13 (depends on 1) The tool of claim 1, wherein the additive(s) comprises a liquid. ### Claim 14 (depends on 1) The tool of claim 1, wherein the additive(s) comprises a gas. ### Claim 15 (depends on 1) The tool of claim 1, wherein the additive(s) comprises a solid. ### Claim 16 (depends on 1) The tool of claim 1, wherein the additive(s) comprises an encapsulated material. ### Claim 17 (depends on 1) The tool of claim 1, wherein the additive(s) comprises a particulate material. ### Claim 18 (depends on 1) The tool of claim 1, wherein the additive(s) is a heat transfer material. ### Claim 19 (depends on 1) The tool of claim 1, wherein the additive(s) adhere to the target. ### Claim 20 (depends on 19) The tool of claim 19, wherein the additive(s) are introduced to the combustion products through a feed. ### Claim 21 (depends on 1) The tool of claim 1, wherein the additive(s) are introduced to the generated combustion products. ### Claim 22 (depends on 21) The tool of claim 21, wherein the feed is at an at least one flow path inlet. ### Claim 23 (depends on 21) The tool of claim 21, wherein the additive(s) are introduced to the combustion products at or adjacent to the flow path(s) exit. ### Claim 24 (depends on 21) The tool of claim 21, wherein, in use, the combustion products are passed over a surface containing the at least one additive. ### Claim 25 (depends on 1) The tool of claim 1, wherein the tool comprises a sacrificial portion. ### Claim 26 (depends on 25) The tool of claim 25, wherein the tool sacrificial portion is configured to be eroded by the directed combustion products, wherein upon eroding, particles and/or portions of the sacrificial portion become part of the combustion products. ### Claim 27 (depends on 1) The tool of claim 1, further comprising a containment arrangement configured to direct the combustion products. ### Claim 28 (depends on 27) The tool of claim 27 wherein the containment arrangement is defined by the propellant source. ### Claim 29 (depends on 27) The tool of claim 27 wherein a combustion zone is contained by the containment arrangement. ### Claim 30 (depends on 1) The tool of claim 1, wherein the propellant source is shaped to combust at a substantially constant rate. ### Claim 31 (depends on 30) The tool of claim 30, wherein the propellant types are homogeneous. ### Claim 32 (depends on 30) The tool of claim 30, wherein the propellant source comprises a laminated section of layers of propellants of different burn rates. ### Claim 33 (depends on 1) The tool of claim 1, wherein the propellant source contains multiple propellant types. ### Claim 34 (depends on 1) The tool of claim 1, wherein the propellant source is fed to the combustion zone. ### Claim 35 (depends on 1) The tool of claim 1, configured such that the generated combustion products exit the flow path in a preferred direction. ### Claim 36 (depends on 1) The tool of claim 1, wherein the tool is moveable with respect to the target. ### Claim 37 (depends on 1) The tool of claim 1, wherein the tool is configured to allow the direction of the combustion products exiting the flow path with respect to the tool to be varied. ### Claim 38 (depends on 36) The tool of claim 36, wherein an angle and/or direction of the combustion products exiting the flow path is varied by a controller using computer numerical controls. ### Claim 39 (depends on 1) The tool of claim 1, wherein the tool is configured to direct the combustion products generated at the combustion zone radially inwards from an outer housing of the tool. ### Claim 40 (depends on 1) The tool of claim 1, wherein the tool is configured to direct the combustion products generated at the combustion zone radially outwards from an outer housing of the tool. ### Claim 41 (depends on 1) The tool of claim 1, wherein the tool has a longitudinal axis and is configured to direct the combustion products generated at the combustion zone in an axial direction with respect to the longitudinal axis. ### Claim 42 (depends on 1) The tool of claim 1, where the tool is configured to deflect the generated combustion products prior to exiting the flow path. ### Claim 43 (depends on 42) The tool of claim 42, wherein the combustion products are deflected by a deflector. ### Claim 44 (depends on 42) The tool of claim 42, wherein the deflector is sacrificial. ### Claim 45 (depends on 42) The tool of claim 42, wherein the deflector comprises an additive. ### Claim 46 (depends on 1) The tool of claim 1, wherein the tool is configured to form at least one combustion products jet. ### Claim 47 (depends on 1) The tool of claim 1, wherein the tool is configured to form a plurality of combustion products jets. ### Claim 48 (depends on 1) The tool of claim 1, wherein the tool is configured to form a single combustion products jet by merging a plurality of combustion products jets. ### Claim 49 (depends on 1) The tool of claim 1, wherein the tool is configured to create pulses of generated combustion products. ### Claim 50 (depends on 49) The tool of claim 49, wherein the sequence of combustion products jets are pulses. ### Claim 51 (depends on 1) The tool of claim 1, wherein the tool is configured to create a sequence of combustion products jets. ### Claim 52 (depends on 1) The tool of claim 1, wherein the tool is configured to cool the target. ### Claim 53 (depends on 1) The tool of claim 1, wherein the tool is configured to subject the target to thermal stress and/or thermal shock imparted partially with the generated combustion products. ### Claim 54 (depends on 1) The tool of claim 1, wherein the tool is arranged such that the combustion products interact directly with the target. ### Claim 55 (depends on 1) The tool of claim 1, wherein the tool is arranged such that the combustion products interact indirectly with the target. ### Claim 56 (depends on 1) The tool of claim 1, wherein the combustion products are adapted to propel an object or material into, adjacent to or through the target. ### Claim 57 A method of initiating a change in a target, the method comprising the steps of: I. providing a tool comprising: at least one propellant source, at least one additive, at least one mechanism for igniting the propellant source(s), and at least one flow path; II. igniting at least one of the/each propellant source(s) such that it/they combust to release combustion products in a flow out of the tool along the flow path towards a target to be changed; wherein the combustion products contain the additive(s), the additive(s) on contact with the target acting as a plugging material, a metal repair material, an activation material, a dissolving agent, a gelling agent, a chemical tracer, and/or a radioactive material.