1 EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report included in this Form 10-K, into the Company's previously filed registration statements on Form S-8 (333-28687), Form S-3 (333-62057) and Form S-4 (333-44361). ARTHUR ANDERSEN LLP Houston, Texas March 31, 1999