EXHIBIT 23.10 [Letterhead of Ryder Scott Company Petroleum Consultants] ENGINEER'S CONSENT We consent to the reference to our appraisal for PennzEnergy Company as of the years ended December 31, 1996, 1997 and 1998, incorporated herein by reference. /s/ RYDER SCOTT COMPANY, L.P. Houston, Texas August 17, 1999