申请人 |
SCHLUMBERGER CANADA LIMITED;PRAD RESEARCH AND DEVELOPMENT N.V;SCHLUMBERGER TECHNOLOGY B.V.;SCHLUMBERGER OVERSEAS S.A.;SCHLUMBERGER SURENCO S.A.;SCHLUMBERGER HOLDINGS LIMITED;SERVICES PETROLIERS SCHLUMBERGER |
发明人 |
RALPH M. D'ANGELO;KENNETH W. WINKLER;DAVID L. JOHNSON;GALE GUSTAVSON;OLIVER C. MULLINS |