Overview

    Offshore drilling is a natural offshoot of the onshore quest for petroleum resources that dates back to 1869. That was the year the first U.S. patent was awarded for an offshore drilling rig, just 10 years after Col. Edwin Drake’s historic first well was drilled in Titusville, Pa. The first offshore wells were drilled either from shore, using angled drilling, or from rigs mounted on piers that extended over the water as far as 1,200 ft/360m. The first of these pier-based wells appeared off the coast of Santa Barbara, Calif., around 1886 and spread from California to the inner-coastal waters of Louisiana and Texas.

    In the Gulf of Mexico, trestles — equipped with rail lines to carry equipment to and from drilling sites — were constructed thousands of feet over the water, connecting several offshore platforms to the beach. This type of drilling allowed for prolific near-shore fields to be developed. But, the wooden pilings that supported the system became unstable under the weight of the heavy drilling equipment and were under constant attack by ocean borers. After the 1938 hurricane season, damaged trestles and equipment were deemed unrepairable and the approach was abandoned.

    Clearly the future was a freestanding offshore structure, or one that could move from one well site to the next. In 1932, what is commonly recognized as the first offshore well was drilled from a platform installed off the coast of Rincon, Calif. Designers recognized that such a structure had to withstand the weight of the drilling equipment and the stress from wind and wave action, currents and storms. Another key concern was the lack of crew quarters and the logistics of transporting crew and materials to and from the platform. Even in the best of conditions it was difficult for workers to travel to and from the rig.

    A breakthrough came during World War II, in the form of military radar platforms built in U.S. and U.K. coastal waters. These “Texas Towers” were so well constructed that some were later used as radio transmission towers after the war. The tower technology was a natural fit for the fledgling offshore oil industry. Exploration showed that there were large fields just offshore that could be exploited using conventional drilling methods, if the industry could find a way to access them.