Exhibit 23 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report dated August 11, 1998, included in this Form 8-K, into the Company's previously filed Registration Statements on Form S-8 (File Nos. 33-37505 and 333-09205). ARTHUR ANDERSEN LLP Tulsa, Oklahoma August 18, 1998