Offshore drilling is one of the primary industries that Armoda supports through our fleet of offshore modules and technical buildings. Today these modules and buildings support a wide range of highly technical vessels and installations, providing accommodation, officing, and utility space. These large facilities now drill in depths thousands of feet below the water’s surface and hundreds of miles offshore. This article follows the evolution of offshore drilling facilities and vessels from their simple beginnings off the coast of California to the multibillion-dollar installations used today.
The beginning of offshore drilling started off the coast of Summerfield, California. Before oil was drilled in the area, the native Chumash people used the tar deposits found to seal the watercraft they used to navigate the channels in the area. Oil prospectors in 1880 used the existence of the tar to begin their search for oil and gas. These prospectors would initially find oil onshore but not in any significant quantities. However, as the prospectors continued their search, they would discover a viable field of oil and gas in what would become the beginnings of the Summerfield Oilfield. This field would grow to up to 40 producing wells.
As the wells were drilled and starting to produce, the prospectors noticed that the wells closest to the ocean produced at a better rate than those more inland. Based on this observation, in 1895, Henry L. Williams drilled two wells on the beach and then a third with promising results. These wells led to the construction of a pier that could support the weight of their land drilling rigs and led to the first offshore drilling rig. The hunch that more oil was located offshore was correct; within the next five years, 150 offshore wells would be drilled in the area. This method would be the prevailing offshore drilling technique with some improvements, such as using steel piers instead of wood.
The next major innovation happened in 1932 when a small oil company built a steel island pier half a mile offshore. Like the piers on the coast, the island pier supported a land-style drilling rig. Unfortunately, the drilled wells did not produce, and a storm destroyed the island in 1940.
Around the same time in Louisiana, oil companies attempted to navigate and drill in the state's wetlands. G.I. McBride of Texaco proposed using a barge equipped with drilling equipment. The barge would be towed to the location, flooding the hulls to sink the barge to the bottom. The drilling equipment would be housed in the upper compartments of the barge, keeping them above the water. This arrangement would give the drilling equipment the necessary stable base so that it could drill without the need for a fixed foundation.
In perusing this concept, Texaco was surprised to find that Louis Giliasso had patented this concept a few years earlier after watching prospectors struggle drilling in lake bottoms in Venezuela. As a result, Texaco would set up a deal with Giliasso granting them exclusive license to use submersible barges and the right to license them to other companies. The submersible barge proved highly effective for its ease of transportation and reduced non-drilling time.
The first “offshore” oil well was completed on November 14th, 1947, 10 miles off the coast of Louisiana at a depth of 18 feet. Drilled by Kerr-McGee, this well is considered the first offshore oil well because the platform was out of sight of land. Also, during this time, the next advancement of barge-based drilling units was created. The Breton Rig 20, designed by John T. Hayward, was a combination of a submersible barge with piled platforms creating a mobile drilling unit that would be used in shallow waters of up to 20 feet. These units used barges with support columns that, when the barge was submerged, would keep the drilling deck above the water line, creating a truly all-in-one drilling unit.
While some would argue that the Benton Rig 20 was the first mobile offshore drilling unit (MODU), most do not believe this because it only operated in shallow inland waters. Because of this, the claim to the first genuinely offshore MODU was given to a rig called “Mr. Charlie” in 1954. Rated for depths of 40 feet of water, this unit used the same principles as a barge that supported a deck, with columns to keep the deck and drilling equipment above the water when the barge was submerged at location. Mr. Charlie would drill hundreds of wells for the next forty years until it was decommissioned. It is now used as an educational rig museum in Morgan City, Louisiana.
While this advancement was happening in the Gulf of Mexico, off the coast of California, companies had to devise other offshore drilling solutions as the shelf dropped off quickly and the water depths didn’t allow for MODUs like Mr. Charlie. So, World War II ships were converted to enable drilling while floating to access the oil in deeper water. Standard Oil, now Chevron's, Western Explorer would be the first floating MODU to use subsea control of a well.
A third type of MODU, the jackup barge, would also have its start during this era. Based on barges used during World War II for construction, these barges have multiple legs that are hydraulically jacked down to the sea floor, raising the barge out of the water. This design allows the barge, and its drilling equipment, to be above the water, providing a stable base for drilling.
With the ever-growing push to drill in deeper waters in the Gulf of Mexico, Shell and Blue Water Drilling combined the floating drilling technology found in Mr. Charlie with a submersible like that of the Benton Rig 20. This idea came by accident as the Blue Water Rig 1’s pontoons were not sufficiently buoyant enough to support the rig. As the unit was being towed back to port with its draught midway between the pontoons and the deck, they noticed the unit’s motions were very small. Shell and Blue Water Drilling decided the unit, semi-submerged and with anchors mooring it to the seabed, would provide a stable platform and allow them to drill in much deeper water than regular submersibles. This accident would lead Blue Water Rig 1 to become the first semi-submersible.
During this time, the use of jackup barges and semi-subs began to increase in popularity, as floating MODUs would begin to decrease with an exception. Dynamic positioning drillships (DP drillships) were developed to operate in deeper waters than the jackups and semi-subs were able to operate. This was achieved by using steerable propellers that would keep the drillship in position and allow for drilling in deeper water without the need for mooring to the seabed.
During this time, the semi-submersible would continue its push into deeper waters and go through multiple generations. The second-generation semi-subs would operate up to depths of 1,000 feet. In the 1980s, the third generation of semi-subs would enable operation in depths of up to 3,000 feet of water. In the 1990s, third-generation units would be upgraded, creating the fourth generation and the push into waters up to 4,000 feet in depth. Finally, in the late 90s, the size and capabilities of fifth-generation units would grow, allowing for operation in much harsher marine environments and reaching drilling depths of up to 7,000 feet.
From the year 2000 to the current era, DP drillships would evolve with the help of new technologies to become larger and capable of drilling in depths of up to 10,000 feet. In addition, semi-subs, jackups, and offshore platforms would all evolve, each taking advantage of new technologies, allowing them to continue to push into deeper waters.
This has been a brief history of offshore drilling and the vessels and facilities that enabled its growth. If you want to learn more about offshore vessels and facilities, you can check out our article about types of offshore drilling platforms which gives a breakdown of the many types of drilling platforms in use today.