The Use Of The Computer And Other Special Tools For Monitoring A Gas Well Blowout During The Kill Operation - Offshore Louisiana

Abstract

On March 24, 1976, Tenneco Oil Company experienced a blowout in the West Cameron 165 Field. West Cameron 165 Well No. 3, a single-sell platform installation, was blowing out of control. By April 11, 1976, the casing strings and the platform had subsided beneath the surface of the Gulf of Mexico, leaving a huge gas boil approximately 100 feet in diameter as the only remaining visual evidence of the blowout. Prior to drilling the relief well to total depth, calculations were made to predict the anticipated bottom hole and surface injection pressures, injection volumes, and injection breakthrough times. These calculations, presented in a graphical format, would serve as guidelines during the actual injection operation. In addition, new methods were employed for utilizing the Hewlett-Packard Quartz Pressure System and side scan sonar equipment to determine if the blowout well was flowing underground and/or beneath the surface of the water. Introduction West Cameron Block 165 is located 32 miles southwest of Cameron, Louisiana, in a water depth of 48 feet. The field was developed by six single-well platform installations. All six wells were completed in the only productive sand in the field, the K-2 Sand. Prior to blowing out, Well No. 3 was the best producer in the field with a flow rate of 13 MMCFD, 90 BCPD, and with a flowing tubing pressure of 2900 psig. Well No. 3 was drilled essentially as a straight hole during November of 1969 and completed in the K-2 Sand with subsea perforations at 9620–26 feet and 9638–57 feet. On March 23, 1976, all six single-sell platform installations in the field were manually shut-in to install new production equipment on the No. 1 Platform, the central gathering platform for this Platform, the central gathering platform for this field. At 7:00 A.M., on March 24, 1976, gas was discovered escaping from around the bradenhead flange of West Cameron 165 Well No. 3. Initial inspection of the area indicated that the flow was occurring primarily between the bradenhead flange; however, gas bubbles were also seen around the legs of the platform. Within two hours, the bradenhead bolts were flow cut and the tree was blown off the bradenhead flange. Well No. 3 was out of control; blowing gas, mud, and sand. Upon being notified of the problem on the morning of March 24, 1976, Tenneco oil Company assembled its "Spill Contingency Task Force". Since the structure of the "Spill Contingency Task Force" was organized in advance, this work force immediately determined that a relief well would be required and began planning strategy to bring the well under control. Subseqnently, this task force became known as the "Blowout Team". The Blowout Team met at least once a day to make recommendations, coordinate the planning, and oversee the execution of various blowout operations. On May 9, 1976, just 47 days after the blowout occurred, the dedicated work of this task force and many people within the Industry was culminated as Well No. 3 was successfully killed. Due to the limited scope of this paper, the actions of the entire blowout operation cannot be detailed. However, the use of the computer and other special tools for monitoring a gas well blowout during the kill operation are discussed herein. A second paper deals specifically with the relief well drilling operations, kill equipment, and the injection operation. INJECTION PRESSURES, VOLUMES, AND TIMES Prior to drilling the relief well (Well No. 12) to total depth, it was necessary that the injection operation be fully understood by all involved. Since Well No. 3 was drilled essentially as a straight hole during 1969 and only single shot directional surveys were taken, then the exact bottom hole location of Well No. 3 was not known.