Djurre H. Zijsling

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Assen, NL

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Patents Grantslast 30 patents

Information Patent Grant
Rotary drill bit for drilling through sticky formations
- Patent number 5,197,554
- Issue date Mar 30, 1993
- Shell Internationale Research Maatschappij B.V. The Netherlands
- Djurre H. Zijsling
- E21 - EARTH DRILLING MINING