EXHIBIT 23.3 [Sproule Associates Limited Letterhead] March 10, 2003 Burlington Resources Inc. 5051 Westheimer, Suite 1400 Houston, Texas 77056 Re: Consent We hereby consent to the reference to our firm name and our review of the estimates of proved reserves of natural gas, oil and natural gas liquids that Burlington Resources Inc. attributed to its net interests in oil and gas properties located in Canada and Argentina as of December 31, 2002, which appears in this Form 10-K. In addition, we hereby consent to the incorporation by reference in the Registration Statements on Form S-8 Registration Nos. (333-91247, 333-95071, 333-52324, 33-22493, 33-25807, 33-26024, as amended in Registration No. 2-97533, 33-33626, 33-46518, 33-53973, 333-02029, 333-32603, 333-40565, 333-60081 and 333-90906) and on Form S-3 Registration Nos. (33-54477, 333-24999, 333-52213, 333-83163, 333-36032, 333-61600 and 333-87170) of Burlington Resources Inc. of the reference to our firm name and our review of the estimates of proved reserves of natural gas, oil and natural gas liquids that Burlington Resources Inc. attributed to its net interests in oil and gas properties located in Canada and Argentina as of December 31, 2002, which appears in this Form 10-K. Sincerely, /s/ KEN H. CROWTHER, P. ENG. -------------------------------- Ken H. Crowther, P. Eng. President