EXHIBIT 23.1
                                                                   ------------



            CONSENT OF INDEPENDENT REGISTERED CHARTERED ACCOUNTANTS


We consent to the  incorporation  by  reference in the  following  registration
statements of Nexen Inc.:

     o    Registration    Statement   No.'s   033-26582,    033-34467,
          033-43426,   033-66538,   033-81334,  333-05494,  333-07344,
          333-09286, 333-13574, 333-118019 and 333-119276 on Form S-8;

     o    Registration   Statement  No.'s  333-09288,   333-10646  and
          333-84786 on Form F-3; and

     o    Registration  Statement  No.'s  333-125019 and 333-128510 on
          Form F-10.

of our reports dated February 7, 2006,  relating to the consolidated  financial
statements of Nexen Inc. (which report expresses an unqualified  opinion on the
financial  statements and includes a separate report on Canada-United States of
America reporting  differences) and management's report on the effectiveness of
internal control over financial  reporting,  appearing in this Annual Report on
Form 10-K of Nexen Inc. for the year ended December 31, 2005.


(signed) "Deloitte & Touche LLP"

Independent Registered Chartered Accountants
Calgary, Canada

February 23, 2006