SCHLUMBERGER LIMITED

                         POWER OF ATTORNEY

The undersigned in his capacity as a director or officer or both
of Schlumberger Limited, a Netherlands Antilles corporation (the "Company"),
does hereby appoint Janet B. Glassmacher, Lynda M. Quagliara and Ellen Summer,
and each of them severally, his true and lawful attorney-in fact with power
to act with or without the other and with full power of substitution and
resubstitution, to execute for him and in his name, place and stead, in his
capacity as a director or officer or both of the Company, a statement of
beneficial ownership on Form 3, Form 4, Form 5 or Form 144, and to file the
same or cause the same to be filed with the Securities and Exchange
Commission.  This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, 5 and 144.


March  23 , 2006                     /s/ Mark Corrigan
                                      Mark Corrigan