A HISTORY OF OFFSHORE DRILLING

Abstract

The offshore drilling industry was born of economic necessity and developed according to the needs of oil exploration operators. From a modest start in 6m of water in 1949, offshore drilling has grown to a fleet of 373 competitive mobile drilling units some of which have the capability to drill in excess of 900m of water. During the process, four types of mobile drilling rigs evolved, each with its own share of the total rig market: submersible, jackup, drillship or barge and semisubmersible. Characteristically, during the growth period, the Industry has periodically over-built and suffered the consequences of rig surplus. From its start in the U.S. Gulf of Mexico, offshore drilling has spread out to encompass every area of the world. The design of rigs has been influenced by economic demand, physical environment, experience, regulatory requirements and technical developments in the drilling industry. Rig construction costs have dramatically increased from 2 million U.S. Dollars, in earliest times, to 20 - 70 million U.S. Dollars now. Personnel who man the rigs were trained from the area of operations with the initial cadre from the United States Gulf of Mexico. Government influence has been profound in determining the level of offshore activity through the control of prices, lease sales, the tax level, environmental measures, and protectionist policies. As long as the oil and gas price remains competitive with other energy sources and the present determination to diversify the petroleum source is maintained, growth of the industry will continue. The form of this growth will be governed by economic and political circumstances and the physical environment in the areas in which economically recoverable hydrocarbons are found.