Patent Yard Sign in
Expired European patentEurope

Device and method for cleaning an underground well

EP 0457879 B1 · Applicant: SOCIETE NATIONALE ELF AQUITAINE (PRODUCTION)

EPO PDF

Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

Read the whole patent

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.

Google PatentsEPO PDF

Why it's free to use

  • Filed December 10, 1990 and granted August 24, 1994. A European patent lasts at most 20 years from filing, so its term ended December 10, 2010.
  • 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 June 10, 2016.
  • 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.
FiledDecember 10, 1990
PublishedNovember 27, 1991
GrantedAugust 24, 1994
Term endedDecember 10, 2010
Application numberEP 91900837
Classification (CPC)E21B37/00

Timeline

Timeline From EPO dates

1991199319951997199920012003200520072009Application filedDec 10, 1990PublishedNov 27, 1991Patent grantedAug 24, 1994Term endedDec 10, 2010

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

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.