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Expired European patentEurope

Method for forming channels of high fluid conductivity in formation parts around a borehole

EP 0005571 B1 · Applicant: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed May 10, 1979 and granted December 30, 1981. A European patent lasts at most 20 years from filing, so its term ended May 10, 1999.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by November 10, 2004.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledMay 10, 1979
PublishedNovember 28, 1979
GrantedDecember 30, 1981
Term endedMay 10, 1999
Application numberEP 79200229
Classification (CPC)C09K8/62 +2 more

Timeline

Timeline From EPO dates

1980198219841986198819901992199419961998Application filedMay 10, 1979PublishedNov 28, 1979Patent grantedDec 30, 1981Term endedMay 10, 1999

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

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