# US 12,006,466 B2 · Dissolvable sleeve for hydrocarbon well completions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,006,466 B2 - Document ID: US12006466B2 - Status: Granted - Kind: B2 - Application number: 17/832,149 - Filed: 2022-06-03 - Published: 2022-12-08 - Granted: 2024-06-11 - Earliest claimed: 2021-06-03 - Assignees: ConocoPhillips Company - Applicants: Conocophillips Company - Inventors: James Rutherford; Roy Middleton - Web page: https://patentgrep.com/patent/US12006466B2 ## CPC - C09K 8/40: Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses - E21B 23/02: for locking the tools or the like in landing nipples or in recesses between adjacent sections of tubing (E21B23/03 - E21B23/06 take precedence) - E21B 33/16: using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B33/146; spacer compositions C09K8/424)} - C09K 8/52: Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning - E21B 2200/08: Down-hole devices using materials which decompose under well-bore conditions - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract The invention relates to the use of a sleeve (9) installed in a liner or casing (1) prior to a cementing operation. Completion equipment in the liner/casing creates an irregular inner profile which can cause cement to get trapped. A wiper dart (3) passed down the casing/liner (1) may have difficulty removing all residual cement (5). By using a sleeve or insert (8) in the liner/casing (1), a smooth inner profile (9) may be created which can be cleaned relatively easily by a wiper dart. Once cementing and cleaning are complete, the sleeve (9) may be removed by wellbore fluid or acid if it is made from a dissolvable material such as aluminum or magnesium. ## Claims ### Claim 1 A process for cleaning a liner or casing prior to completion, wherein the liner or casing has a region with a non-uniform inner profile, the process comprising: a) installing a protective sleeve in the liner or casing, the sleeve extending over the said region, the protective sleeve having a through bore with a substantially circular section; b) passing a wiper dart or other cleaning device through the said region; c) removing the sleeve; and d) performing the completion; wherein an inner surface of the sleeve is tapered at a distal end of the sleeve, at a proximal end of the sleeve or at both the distal and proximal ends of the sleeve, whereby the wiper dart negotiates a gradual change in diameter on passing through the said region. ### Claim 2 (depends on 1) The process according to claim 1, wherein the sleeve has no abrupt changes in diameter or shoulders. ### Claim 3 (depends on 1) The process according to claim 1, wherein the said region comprises completion or other equipment having a non-uniform inner profile. ### Claim 4 (depends on 3) The process according to claim 3, wherein the sleeve has an outer profile complementary to the non-uniform inner profile of the said equipment. ### Claim 5 (depends on 1) The process according to claim 1, wherein the step of removing the sleeve comprises dissolving the sleeve. ### Claim 6 (depends on 5) The process according to claim 5, wherein the sleeve is dissolved in a fluid selected from well bore fluid, acid, alcohol, surfactant, and combinations thereof. ### Claim 7 (depends on 1) The process according to claim 1, wherein the step of removing the sleeve comprises milling away the sleeve using a milling tool. ### Claim 8 A sleeve having a through bore with a substantially circular cross section with no abrupt changes in diameter and an outer surface profiled in a complementary manner to a non-uniform inner profile of a region of liner or casing, the sleeve being made from a material which is dissolvable or millable, wherein an inner surface of the sleeve is tapered at a distal end of the sleeve, at a proximal end of the sleeve or at both the distal and proximal ends of the sleeve. ### Claim 9 (depends on 8) The sleeve according to claim 8, being made from aluminium, magnesium, thermoplastic, composite, or a combination thereof. ### Claim 10 An assembly comprising: a) a liner or casing having a region with a non-uniform inner profile; and b) fitted to the said region, a sleeve having a through bore with a substantially circular cross section with no abrupt changes in diameter and an outer surface profiled in a complementary manner to the non-uniform inner profile of the said region of liner or casing, the sleeve being made from a material which is dissolvable or millable, wherein an inner surface of the sleeve is tapered at a distal end of the sleeve, at a proximal end of the sleeve or at both the distal and proximal ends of the sleeve; whereby a bore through the assembly is provided, the bore having a circular cross section with no abrupt changes in diameter or shoulders. ### Claim 11 (depends on 10) The assembly of claim 10, wherein the said region comprises completion or other equipment having a non-uniform inner profile. ### Claim 12 (depends on 10) The sleeve according to claim 10, being made from aluminium, magnesium, thermoplastic, composite, or a combination thereof.