# US 9,518,442 B2 · Easy drill slip with degradable materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,442 B2 - Document ID: US9518442B2 - Status: Granted - Kind: B2 - Application number: 14/189,214 - Filed: 2014-02-25 - Published: 2014-08-14 - Granted: 2016-12-13 - Earliest claimed: 2011-05-19 - Assignees: Baker Hughes Incorporated - Applicants: Baker Hughes Incorporated - Inventors: Richard Yingqing Xu; Zhiyue Xu - Web page: https://patentgrep.com/patent/US9518442B2 ## CPC - E21B 33/129: with mechanical slips for hooking into the casing (E21B33/122, E21B33/124 take precedence) - E21B 33/134: Bridging plugs - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Slip elements for a downhole tool include an inner body portion that is substantially formed of a material that is degradable by dissolution in response to a dissolving fluid and a hardened, resilient, radially outer contact portion. The inner body portion may be formed of magnesium, aluminum or iron based powder. ## Claims ### Claim 1 A slip element comprising: an inner body portion that is formed of a dissolvable material that is dissolvable in response to a dissolving agent; and an outer contact portion in contact with the inner body portion and being formed of a material suitable to provide engaging contact with a tubular member near the outer contact portion and that is not dissolvable by the dissolving agent or dissolvable at a slower dissolution rate relative to the dissolvable material. ### Claim 2 (depends on 1) The slip element of claim 1 wherein the dissolvable material comprises magnesium-based, aluminum-based or iron-based composite. ### Claim 3 (depends on 2) The slip element of claim 2 wherein the dissolving agent is from the group consisting of potassium chloride, sodium chloride, calcium chloride, calcium bromine, hydrogen chloride, acetic acid and formic acid. ### Claim 4 (depends on 1) The slip element of claim 1 further comprising a laminate to preclude premature dissolution of the inner body portion. ### Claim 5 (depends on 1) The slip element of claim 1 wherein the inner body portion and the outer contact portion are affixed to each other by an adhesive. ### Claim 6 (depends on 1) The slip element of claim 1 wherein the inner body portion and the outer contact portion are interconnected by a transition gradient zone. ### Claim 7 (depends on 1) The slip element of claim 1 further comprising a plurality of openings formed through the outer contact portion. ### Claim 8 (depends on 1) The slip element of claim 1 wherein the slip element is incorporated within a gripping system for a downhole tool having a plurality of slip elements. ### Claim 9 (depends on 8) The slip element of claim 8 wherein the downhole tool comprises a packer, anchor, plug, setting tool, bridge plug, lock or fishing tool. ### Claim 10 (depends on 1) The slip element of claim 1 wherein the inner body portion presents a first axial end and a second axial end that is opposite the first axial end and wherein: the outer contact portion extends from the first axial end to the second axial end. ### Claim 11 A downhole tool having a gripping system for resisting axial or torsional movement within a flowbore of a surrounding tubular, the gripping system comprising: a setting cone; a slip element that is selectively radially moveable with respect to the setting cone between unset and set positions, the slip element comprising: an inner body portion formed of a dissolvable material that is dissolvable in response to a dissolving agent; and an outer contact portion in contact with the inner body portion and being formed of a material suitable to provide engaging contact with a tubular member near the outer contact portion and that is not dissolvable by the dissolving agent or dissolvable at a slower dissolution rate relative to the dissolvable material. ### Claim 12 (depends on 11) The downhole tool of claim 11, wherein the inner body portion further comprises a laminate to preclude premature dissolution of the inner body portion. ### Claim 13 (depends on 11) The downhole tool of claim 11 wherein the dissolvable material comprises magnesium-based, aluminum-based or iron-based composite. ### Claim 14 (depends on 13) The downhole tool of claim 13 wherein the dissolving agent is from the group consisting of potassium chloride, sodium chloride, calcium chloride, calcium bromine, hydrogen chloride, acetic acid and formic acid. ### Claim 15 (depends on 11) The downhole tool of claim 11 wherein the inner body portion and the outer contact portion are affixed to each other by an adhesive. ### Claim 16 (depends on 11) The downhole tool of claim 11 wherein the inner body portion and the outer contact portion are interconnected by a transition gradient zone. ### Claim 17 (depends on 11) The downhole tool of claim 11 wherein the inner body portion presents a first axial end and a second axial end that is opposite the first axial end and wherein: the outer contact portion extends from the first axial end to the second axial end. ### Claim 18 (depends on 11) The downhole tool of claim 11 wherein the outer contact portion further comprises a plurality of openings formed therethrough. ### Claim 19 (depends on 11) The downhole tool of claim 11 wherein there is a plurality of said slip elements. ### Claim 20 (depends on 11) The downhole tool of claim 11 wherein the downhole tool comprises a packer, anchor, plug, setting tool, bridge plug, lock or fishing tool. ### Claim 21 A method of releasing a downhole tool that is set within a flowbore from the flowbore, comprising the steps of: a) providing a set downhole tool having: a setting cone; a slip element that is selectively radially moveable with respect to the setting cone between unset and set positions, the slip element comprising: an inner body portion formed of a dissolvable material that is dissolvable in response to a dissolving agent; an outer contact portion in contact with the inner body portion and being formed of a material suitable to provide engaging contact with a tubular member near the outer contact portion, the material forming the outer contact portion being not dissolvable by the dissolving agent or dissolvable at a slower dissolution rate relative to the dissolvable material; and b) flowing a dissolving agent within the flowbore to dissolve the inner body portion. ### Claim 22 (depends on 21) The method of claim 21 further comprising the steps of: engaging a top portion of the downhole tool with a milling device; and removing a portion of molding surrounding the inner body portion to at least partially expose the inner body portion to the flowbore and the dissolving agent. ### Claim 23 (depends on 1) A method of setting a downhole tool with a gripping system having the slip element of claim 1, the method comprising the step of moving the slip element with respect to a ramp of a setting cone to cause the slip element to be urged radially outwardly into gripping engagement with a surrounding tubular.