DEVELOPMENT OF A DEEP-SEA EXPLORATION VENTURE.

The author describes the evolution of the drilling vehicles from 'posted deck' barges used in the early 1950s to the sophisticated Sedco-445 drillship, dynamically positioned and operating in water depths of more than 2000 ft. Other problems caused by operating at such depths have had to be overcome and the article describes how well-head control systems have been modified and how conventional guide wires have been abandoned in favor of an acoustical method with a jet steering device for well-head re-entry.