Floating Drilling Experience in Santa Barbara Channel, California

This paper was prepared for the 40th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in San Francisco, Calif., Nov. 6–7, 1969. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. The equipment and practices for two floating drilling vessels working in water depths greater than 1000 feet in the Santa Barbara Channel have been designed to provide maximum reliability and safety. Experience to date has shown the systems to be efficient and to have met design criteria. Introduction Since the Federal Lease Sale in the Santa Barbara Channel of February 6, 1968, Humble has drilled fourteen wells with floating rigs in water depths ranging from 280 feet to 1300 feet. Although the water depth for some of these wells exceeds previous industry experience, the environment in the Channel is relatively mild. Historical data have indicated that the probable yearly maximum conditions in the central Santa Barbara Channel would not exceed:Five-minute average winds of 65 knots from the west and northwest or from the east and southeast.Significant wave heights of 16 feet with a period of 13 seconds. Maximum waves associated with this sea state would be about 30 feet.Surface or near surface currents of 2.4 knots parallel to the California coastline. The data have shown generally that these conditions occur for only a very small percentage of the time in winter months in the main part of the Channel east of Point Conception. Near the west end of the Channel, a yearly maximum significant wave height of 18 feet might occur with greater frequency.