Special Anniversary - The history of offshore: developing the E&P infrastructure

A number of companies reasoned that oil fields that extended to the coastline might reach out beneath the Gulf of Mexico. If so, they could be tapped from offshore, where plenty of leases were available – at bargain prices. Onshore geophysical equipment had been modified to allow producers to obtain fundamental reflection seismic records over water, and early marine surveys indicated that classic piercement-type salt domes – around which many onshore oil accumulations could be found – were numerous offshore.

Several attempts to develop Gulf of Mexico oil had been made before the war, most of them unsuccessful. One operation, however, spearheaded in 1937 by Pure Oil Co. and partner Superior Petroleum, did pay off. It was conducted on a 33,000-acre state offshore lease near the town of Creole in Calcasieu Parish about 20 mi east of Cameron, Louisiana. The companies built a 30,000-sq-ft wooden platform in 14 ft of water. Though the platform was erected less than a mile from dry land, its mere existence set a record for both platform size and water depth for the Gulf.

Using a land-type drilling rig assembled on the platform's deck, Pure-Magnolia's first well, drilled to a depth of 9,400 ft, produced commercial quantities of oil. The partners expanded the platform's size, and using directional drilling techniques, subsequently completed 10 more wells. At the time, drilling was conducted only during the day, with crews returning to shore as evening fell, traveling aboard leased shrimp boats and other locally based vessels.

Ultimately this operation, whose oil was transported to shore in tank storage barges, was christened the Creole field. It continued to produce for more than 30 years, yielding nearly 4 MMbbl of oil and proving early on that offshore E&P could be a highly lucrative enterprise.

null

The most important historical aspect of the Creole platform was that its discovery well was the first oil producer ever drilled from a fixed platform in the Gulf.

Starting the offshore transition

The Creole field was a logical step in the evolution of the petroleum industry, which had been born nearly 100 years earlier with the successful Drake well in Pennsylvania. The industry's growth did not become noteworthy until the 1901 Spindletop discovery on the Texas Gulf Coast. Spindletop ushered in what today is known as the Petroleum Age. Subsequent discoveries of large new reserves around the country, along with advances in refining techniques, made crude oil the basic feedstock for US industrial and economic growth. Motor gasoline, its primary product, gave Americans a new auto-mobility, and demand skyrocketed as the country phased rapidly from a largely agrarian culture into a more urban society.

The decades after Spindletop witnessed rapid industry expansion across the nation. Using newly developed geophysical exploration techniques to support geological studies, oil prospectors spread the search to Mexico, Canada, South America, and half-way across the world to eastern Europe and the Middle East. Technology development continued apace. By the beginning of World War II, US exploration had expanded widely into more isolated, less-hospitable areas. Among these were the salt marshes and inshore lakes and bays along the coastlines of Alabama, Mississippi, Texas, and Louisiana. So, it wasn't difficult for oilmen to imagine that, if the right equipment were available, they could push seaward to wrest production from beneath the open waters of the Gulf.

Precedents for offshore drilling already had been set. Early 20th century explorationists had succeeded in producing oil from beneath water-covered areas. Using crude wooden trestles and platforms, drillers had coaxed oil from beneath the Pacific Ocean just off the California coast and had made modest gains in developing crude oil and associated natural gas from beneath inland water bodies like Lake Erie and the cypress-studded shallows of Louisiana's Caddo Lake. By the 1930s, drillers were developing giant oil reservoirs in Venezuela's Lake Maracaibo. Snippets of news leaking out of the highly secretive Soviet Union indicated that drillers there were producing oil from beneath their own "great lake," the Caspian Sea.

Floating rigs to locations

The true birth of the offshore petroleum industry stemmed from experience gained during the 1930s-40s by US oil companies that moved drilling and production equipment to well sites in the Gulf Coast's so-called "transition zone." There, between dry land and the marshy, shallow-water flats infused regularly with tidal flow from the Gulf, producers attained valuable know-how drilling in a semi-protected, partially marine environment.

To do so, engineers created the first truly mobile marine drilling equipment – inland water drilling barges, i.e., "dumb" steel barges on which rigs were installed to drill over-water wells. These barge rigs, designed to be towed down bayous, rivers, and dredged-for-purpose canals to watery well sites, were ballasted to rest on the bottom for drilling. Once wells were completed, the barges were refloated and towed away to new well sites while wooden structures were erected around wells both to protect them and provide a platform from which to maintain and service them. Small-diameter pipelines that traversed open-water areas on their way to dry land tie-ins transported produced oil.

Oil companies recognized the need to reach farther offshore, into the Gulf's open waters. The expensive and vulnerable fixed wooden platforms from which even wildcat wells had been drilled were not practical for such projects. Also, fixed-platform drilling was extremely time-consuming. Sinking even wildcat wells involved building the platform, moving a rig to it, drilling, disassembling the rig, and then, if the well was unsuccessful, tearing down the platform. This drawn-out process sometimes took months to complete. Offshore operators wanted more mobility, and because true invention stems from necessity, they got it.

A 'tender' tale

In 1946, engineering specialists with Oklahoma-based Kerr-McGee Oil Industries conceived a way to bring portability to offshore drilling by converting a 327-ft surplus naval materials barge into a towable drilling "tender" that, in conjunction with a small fixed platform, could drill wells relatively quickly. Kerr-McGee, as operator for partners Phillips Petroleum and Stanolind Oil & Gas, acquired a barge, modified it to hold drilling machinery and consumables, and used it to service a prefabricated wood and steel drilling platform. Kerr-McGee erected the platform on a shallow-water lease in the Ship Shoal area off southwestern Louisiana about 11 mi from the nearest point of land. The water depth was about 18 ft.

Because most of the drilling equipment and rig power was installed aboard the tender, the required platform supported only the derrick and draw works, so it was only a quarter the size of conventional wooden platforms. That alone cut construction costs significantly. In the early fall of 1947, the company mobilized its new tender-platform combination – dubbed Rig 16 – to drill a producing well that flowed at 400 b/d of oil. Once that well was completed, the tender, derrick, and draw works were towed to another small platform in somewhat deeper water several miles away, with the entire move accomplished in only three or four days.

Additionally, since the tender contained quarters and a galley for both drilling workers and ship's crew, Kerr-McGee was able to expand drilling into a round-the-clock operation. Crews worked 12-hour shifts for two weeks at a time, and then rotated to and from shore via former naval crash boats converted into fast transport vessels. This crew change routine became the model for those in effect today.

null

The company also operated a refitted self-propelled landing ship-tank (LST) to bring drilling supplies from the closest supply point at Morgan City, 45 mi away.

Kerr-McGee's initial well, though recognized almost immediately for its revolutionary drilling techniques, later earned kudos for having been the world's first producing oil well drilled out of sight of land. In effect, the well – and the rig that drilled it – established offshore E&P, once and for all, as a viable industry.

Though the company's drilling specialists patented their new rig design, they never protested when other companies, fascinated by the tender-platform combination, began purchasing surplus naval barges and LSTs to mount their own offshore programs. Soon, demand sent the price for such vessels sky-high, and Gulf Coast shipyards contacted operators, eager to fabricate slightly more expensive, purpose-built tenders from the keel up.

A sea of new ideas

Naturally, as producers acquired more offshore leases, the water above them also deepened. As drilling projects moved farther seaward, they faced the fact that using fixed platforms for exploratory wells had begun to approach the economic limit, even with tender-assist. Operators needed more mobility, and found a way to get it, back up in the transition zone.

In 1948, marine engineer John T. Hayward, working with a group of independent companies with deeper water offshore leases to explore, mused about the self-contained inland drilling barges used so widely in bays and inland lakes. Barges were limited to the shallows – say, 10 ft or so – since any size scale-up would expose too much surface to winds, and even moderate tidal currents could blow them off location. So, Hayward developed a submersible barge design that incorporated columns on top of the barge deck that would support a drilling deck high enough to cancel any interference from heightened weather conditions. The top deck could support an entire drilling rig. Once the barge section was lowered to the bottom, wave forces contacted only the columns, with the drilling platform raised to a safe distance above water. Additionally, Hayward's design included pontoons on either side of the barge, which he felt would provide both stability and displacement control while the hull was sunk for drilling and when it was raised afterward. The rig was designed to work safely in water depths to about 20 ft.

Despite his oil company clients' doubts as to the efficacy of the pontoons in keeping the rig from falling onto its side during ballasting-deballasting, Hayward convinced them to build it. Completed in 1949, the unit, named the Breton Rig 20, was used – without incident – to drill a number of wells in the Gulf. Each well was 10 to 15 mi apart, yet the rig was drilling within a day or two of leaving the previous well site.

Industry breaks for government

The one true shutdown experienced by the US offshore industry occurred during several years of wrangling between the coastal states and the federal government about jurisdiction over the country's offshore territory.

After World War II, concerned about the increased discoveries in the Gulf, the federal government recognized that because US oil production often entered periods of production gluts, it was up to Washington D.C. to regulate offshore drilling activity, and thereby conserve the nation's petroleum resources from over-development. Several coastal states, however, claimed sole jurisdiction off their shores, and by 1947 the fight – in the form of lawsuits – was on.

During the several years of squabbling that ensued, neither the states nor the feds conducted any sales of offshore leases, leaving operators to slowly, but painstakingly, test their existing leases with the drillbit.

The so-called "tidelands controversy" bounced around both federal and state court systems until 1953, when President Dwight D. Eisenhower and Congress stepped in to pass both the Outer Continental Shelf Lands and the Submerged Lands acts. Combined, these bills awarded coastal states jurisdiction of 3 mi offshore from the low tide line, with the federal government controlling all submerged lands beyond that point to the continental margin. Oddly enough, two states, Texas and Florida, argued and prevailed in extending their jurisdiction to 3 marine leagues (about 10.4 mi) because that demarcation had marked their stated territorial jurisdiction before entering the union. Following passage of the bills, both the federal and state governments re-started their offshore leasing programs.

The controversy did have some benefit to the industry, because while the leasing moratorium lasted, operators looked at their exploration hole cards much more closely as they tested existing leases. The time-out also allowed budding inventors to more thoroughly detail their plans for new offshore technology, such as mobile drilling units.

Keeping the rig on bottom

John Hayward's "submersible" offshore rig design opened the door for improvements by others that resulted in greater water-depth capabilities. Soon, naval architects entered the rig design picture, providing the industry with more precise input and tacking on a whole new career direction for themselves. Incorporating naval architecture into offshore facilities design proved to be indispensable during the years that followed.

Among other operators working offshore in the early 1950s, Kerr-McGee went on to cause several larger submersibles to be built, raising column heights and upgrading designs for increased water depth capabilities. As a start, in a 1954 joint venture with a new offshore contract drilling company – Ocean Drilling & Exploration, founded by Alden J. "Doc" LaBorde – Kerr-McGee built the Mr. Charlie submersible, which could drill in water depths to 40 ft deep. Designed by LaBorde himself, the rig was fitted with pontoons on either of the barge's long ends, which allowed it to be submerged sequentially by ballasting one pontoon until its end touched bottom, then lowering the other end slowly by flooding its pontoon. This provided greater stability than previous flotation-assist designs.

At the same time, LaBorde, a true offshore industry pioneer, designed the first built-for-purpose offshore supply vessel, a creation that canceled forever the need to modify naval and fishing vessels to move drilling supplies and personnel to rigs offshore. It also spawned a new generation of offshore vessel services. Subsequent supply vessel designs were later combined with other types of craft used for rig crew transport, towing, mooring, diving support, and other offshore services. Additionally, other transport modes entered the industry, including helicopters, which ferried crews to and from offshore points.

Meanwhile, submersible rigs continued to catch on. By the mid-1950s, Kerr-McGee had built its Rig 46, which used large cylinders instead of fixed columns to bring the rig's water-depth capability to 70 ft. The entire barge hull could be ratcheted up and down on the cylinders, improving control during the ballasting-deballasting process. The ability to snug the barge hull up to the bottom of the drilling platform also streamlined the rig's towing characteristics significantly.

In 1956, Kerr-McGee built its Rig 54 submersible, a new, triangular design with no lower barge or mat. The rig's entire large-diameter, bottled understructure could be submerged to provide better sea-bottom contract. Once resting on bottom, Rig 54 provided a water-drilling deck clearance of 25 ft in up to 175 ft of water.

Other deepwater submersible-type rig designs were constructed, but Rig 54 was the last large unit of its type to be built before more revolutionary rig designs overtook the industry.

'True' mobile rigs hike water depths

While submersibles afforded operators the ability to develop vast expanses of acreage off Louisiana and Texas, the high success rate of offshore drilling compelled producers to seek equipment rated for even greater water depth. They also sought rock-solid rig stability for drilling in deeper water, where even routine waves and currents were strong enough to jostle bottom-supported equipment off station.

Several companies investigated the concept of installing "legs" on rigs, which could be lowered to the bottom and then "jacked" downward even more to elevate the entire drilling deck above the water's surface. This jackup idea was a rather old one, having been used since the 1930s to provide stable, mobile offshore docks for various marine construction projects. Allied forces off Normandy used variations of such docks during the D-Day invasion of Europe in 1944.

In 1950, Col. Leon B. Delong – credited with coming up with the most workable jackup design of that time – built several self-elevating platforms for radar towers in about 60 ft of water off the US East Coast. The idea was that once they had served their purpose, self-elevating mobile platforms could be jacked down and redeployed, music to the ears of offshore operators.

That same year, Magnolia Petroleum gave the jackup idea an offshore petroleum dimension by incorporating it in the design of a production platform they installed in the Gulf in 30 ft of water. However, the platform was designed so that once jacked up, it remained so permanently.

By 1954, oil companies had begun to bow out of owning their own offshore drilling equipment. Instead, they entrusted the actual drilling – and rig construction – to outside companies. In that year, several new marine drilling contractors incorporated the DeLong concept into jackup barges equipped specifically for drilling. These included The Offshore Company's Barge No. 1 and Glasscock Drilling's Mr. Gus, both of which were used successfully to drill wells in up to 100 ft of water. Almost immediately, jackups became as important to the offshore industry as the three-corner milking stool was to dairy farmers.

Meanwhile, among others, the shipbuilding division of Bethlehem Steel Corp., with a large shipyard at Beaumont, Texas, and the R.G. LeTourneau Co., an earth-mover manufacturer based in Vicksburg, Mississippi, patented separate jackup rig designs, which they marketed to the fast-growing new breed of offshore drillers.

In 1956, the LeTourneau company delivered its first jackup – named the Scorpion – to a start-up contractor, Zapata Off-Shore Co., founded by George H.W. Bush. Subsequently, Zapata and others ordered more LeTourneau rigs, each with new design elements that increased the rigs' water depth rate. Bethlehem's mat-supported jackup design also became popular, and new contractors ordered a number of their units – each designed for increased water depths. Meanwhile, separate but similar jackup designs were introduced, and by the 1980s, jackups were being fabricated by shipyards all around the world, with water-depth capabilities increasing over time to more than 300 ft.

Drilling in 'semi' deep waters

The allure of finding oil and gas off the US West Coast had long intrigued major oil companies. Several operators had headquarters in that area and were intimately familiar with the regional geology. In southern California, onshore field development, coupled with additional discoveries along the state's shoreline, indicated the existence of robust hydrocarbon potential beyond the immediate coastal boundary.

Because water depths reach more than 1,000 ft only a few miles out, oil companies recognized that bottom-supported rigs were not adequate. Only some form of floating rig would do for exploratory work in deepwater. Fixed steel platforms could be used to develop discoveries if recoverable reserves were found in large enough volumes.

Technology development for floating drilling moved in several directions. In the mid-1950s, Shell Oil Co., in conjunction with the US Navy and the University of California, was interested in deepwater drilling not only along the Pacific Coast, but in other deepwater areas of the world. So, Shell engineers worked on ways to partially ballast a hull while removing most of the motion such hulls experienced when afloat at sea. A goal was to solve such motion created for the conductor string necessary to drill wells. On conventional offshore rigs, the conductor rose from the seabed through the water column, ending at the blowout preventer stack just below the drilling deck. But this was true only for rigs with full sea-bottom contact. For floating rigs, the conductor would have to absorb the sea's motions without kinking or breaking.

This research proceeded throughout the 1950s, and Shell engineers and scientists also investigated seafloor wellhead systems, wellhead re-entry, and the use of both fixed and buoyant, remotely operated vehicles to help accomplish those and other subsea tasks. That pioneering work resulted in much of the highly dependable subsea production equipment used offshore today. Much of the work took place at Shell's research lab in Houston, but some of it also was conducted in the company's California offices and at parent company Royal Dutch/Shell's research labs in the Netherlands.

After designing a deballasted, semi-floating tubular hull, Shell and several equipment manufacturers then fashioned a free-standing conductor, or riser, that with the aid of tensioners, would allow the hull and its drilling system to be moored over subsea wellhead equipment, free from direct contact with the bottom. With this tensioned riser and a gimbaled rotary, the hull could stay connected to the well, rising, falling, and yawing with the ocean's heave, pitch, and roll, regardless of water depth. After long-term testing of several prototypes, Shell joined with a new drilling contractor, Bluewater Drilling Co., to develop a ballasted, column-supported structure they called a "semisubmersible" drilling unit. This first semi, built in 1962, was the Bluewater No. 1. An improved unit, the Bluewater No. 2, followed.

Meanwhile, back in the Gulf, where submersibles and jackups were nearing their practical water depth limits around 300 ft, Ocean Drilling & Exploration (Odeco), Doc LaBorde's company, drew up its own semisubmersible design. The resulting rig, the Ocean Driller, was built in 1963. It had a V-shaped hull that, while semi-ballastable for deepwater, could rest on bottom in shallower water, allowing its use as a submersible and giving it more versatility for working across the Gulf OCS.

Drillships cap deepwater fleet

Concurrent with the research that eventually produced the semisubmersible, Shell joined with Conoco, Union of California, and Superior to form the CUSS group, which targeted deepwater drilling off California. The group experimented with various forms of motion-restricted, ship-shape vessels.

The CUSS group started in 1953 with a converted, 300-ton naval petrol craft to which was added a draw works and an over-the-side drilling floor and derrick, which caused unmanageable listing problems. This vessel, the Submerex, was succeeded by a converted naval deepsea barge whose drilling rig worked directly over a hole – nicknamed the "moon pool" – fabricated amidships, allowing both rig and derrick to be placed over the barge's midline, rather than over the side. This second, much larger and more stable unit was called the CUSS I.

Tightly moored by a series of anchor chains and buoys, the CUSS I allowed the use of the drillstring itself to convey the blowout preventer stack and drilling base to the sea-bottom, eliminating the need for a riser. A simple slip-joint was added to the drillstring to compensate for vertical motion. This non-self-propelled barge was capable of drilling in water depths to 350 ft, and easily withstood the roughest storms the Pacific Ocean could offer.

When the CUSS group disbanded in the mid-1960s, the CUSS I served as the core vessel for a new offshore contract driller, Global Marine, which went on to build a series of much larger self-propelled drillships. Once water depths presented anchor-handling and sheer weight problems, contractors experimented with electronically operated dynamic positioning systems that, using powerful thrusters, could keep the vessel over the wellhead even in great water depths and on storm-tossed seas. For example, with only a rudimentary station-keeping system, the CUSS I took cores in more than 11,000 ft of water during the short-lived MOHOLE project. In fact, Global Marine supplied the first drilling/coring vessel for the Deep Sea Drilling Project, a government-sponsored deep-drilling initiative that continues today. Meanwhile, Glomar drillships and those of other companies joined semisubmersibles to spread deepsea drilling to the world's four corners.

Since then, both the semisubmersible and drillship designs have been enhanced and combined to work with seafloor production and pipeline gathering systems in most of the world's deepwater exploration areas. Additionally, lighter but stronger anchor mooring systems were developed to allow both types to work routinely today in water depths exceeding 5,000 ft. In fact, semisubmersibles with both conventional mooring and dynamic positioning systems are the second most prevalent rig in the world rig fleet, behind jackups. Dynamically positioned drillships, while fewer, are used to drill in remote, often ultra-deepwater, areas where conventional mooring is not practical. Additionally, semis also are used extensively in some parts of the world as semi-permanent floating production stations, servicing scores of subsea wellheads and other seafloor production equipment.

Offshore production, flow solutions

As more rig mobility was achieved for faster exploratory drilling, offshore operators continued to use fixed drilling/production platforms to develop newly discovered reservoirs. Production volume, not drilling speed, was the crucial issue. When delineation drilling had established the areal extent of a new field, engineers would determine the point or points at which such platforms could be installed for optimum development effectiveness using directional drilling techniques.

Beginning in the 1950s, the prefabricated steel tubular platform "jacket" served as the foundation for modular, above-water production equipment arrays, including removable drilling rigs, "dry" wellheads, and deck-mounted process equipment. The jacket's legs also served as ocean-bottom tie-ins for subsea pipelines laid to shore. Fixed platform designs, pioneered by companies like Brown & Root and J. Ray McDermott, have since been deployed all around the world, giving birth to ever-heftier marine heavy-lift equipment. Also, as platform fabrication became more competitive, yards sprang up in many countries, giving the "float-over" transportation industry a major economic boost.

Initially, jackets were towed out to their locations atop dumb barges, and then manhandled by derrick-mounted cranes to the bottom to be secured with piles. That method segued into floating the jacket out, grabbing it with cranes, then uprighting it via controlled buoyancy prior to sinking it to the seafloor. Some deepwater platforms were built in several pieces. Once completed, they were floated out to be flooded individually, and then fitted together, one atop the other.

In the late 1970s, as water depths around discoveries flew past the 600-ft OCS margin, operators once again began looking for ways to cut their dependence on bottom-connected structures. Fabrication, installation, and other costs related to fixed platforms were becoming prohibitive, particularly in water depths of 800 ft or more.

By the 1980s, a trend toward using floating production equipment began developing around the world. It pioneered installation of several types of buoyant, tethered structures in medium-depth areas of the North Sea and the Gulf. During the 1990s, floaters became more numerous with deepwater discoveries in the Gulf and off Brazil and West Africa. Today, though fixed platforms are still used extensively in shallow water, lighter, more easily moored floating production facilities like tension-leg platforms, guyed towers, and spars are being used for producing deepwater and ultra-deepwater fields around the world.

While early offshore operators offloaded oil and gas production into barges and small tankers via storage tanks erected on platform decks, it wasn't long before marine construction contractors drew on their hard-won experience with laying pipe beneath inland bays and lakes, and pushed the process into ever deeper water. Large, complex marine pipelay and bury barges, coupled with better welding, pipe-coating, and line-weighting technologies, resulted in an expanding global offshore pipeline installation market for contractors like Brown & Root, McDermott, and others.

Industry predicts own success

While three-fourths of the earth's surface is covered by water, the offshore petroleum industry has made its way from modest beginnings in the Gulf of Mexico to a vibrant, necessary industry, with presence on practically every continental shelf and in every ocean of the world, excluding Antarctica.

In 1997, the industry commemorated its 50th anniversary, basing the celebration on Kerr-McGee's drilling in the Gulf of Mexico of that first producing well out of sight of land.

In terms of technology development, the industry's ability to wrest oil, gas, and other minerals from beneath the world's oceans has been rapid. But that hasn't been particularly surprising. Ever since "Long John" Latham published the first issue of Offshore Magazine in April 1954 – a half-century ago this year – its editorial and advertising content has reflected the absolute certainty with which the industry has predicted its own growth, and then has exceeded it.

That's still a heckuva job.

'Offshore' search moves to Caddo Lake

If the term offshore creates a vision of vast stretches of water beyond a pounding surf line, it's perhaps useful to know that after California's pier-based offshore development, the next important chapter of offshore history occurred far inland – hundreds of miles from the open sea.

In the area around Caddo Lake in northwestern Louisiana, companies founded on the success of the giant Spindletop discovery in bordering Texas began looking for oil. What they found most often was natural gas, then a dangerous "nuisance" product of exploration. A market simply did not exist for the gas usually associated with oil production, and pure gas wells often were plugged and abandoned. Nevertheless, oil companies quickly grabbed most of the leases in the area and drilled a few gas wells to supply limited local markets. Shreveport, Louisiana, used natural gas to light streets and to supply cooking fuel for homes.

In 1907, however, a scout for Gulf Oil Corp. studied maps of the Caddo Lake area and calculated that in addition to the gas prevalent in the area, oil might still be found. Looking at the lake itself, the scout imagined that the westward drift of the area's gas sands – which carried them under the lake – just might be where the oil reservoir lay. He then convinced Gulf management to obtain 8,000 acres of leases in the lake.

Calling on the lore created by the California pier drilling 10 years earlier, Gulf brought floating pile-driving equipment up the Mississippi and Red rivers to the lake, along with a fleet of small boats and a disassembled steam-powered rotary rig. There, they drove pilings using logs from the cypress forests in the area, upon which they built planked platforms to support drilling and production operations.

The Gulf scout was correct; there was oil beneath the lake, along with the gas.

Under the development plan, each drilling/production platform supported a derrick and a gas-driven generator, and each producing well was connected to shore by a 3-in. pipeline laid along the lake bottom to other platform-mounted gathering/separation stations.

During the next 40 years, Gulf drilled more than 250 wells and produced 14 MMbbl of oil from beneath Caddo Lake. By doing so, the company created a successful prototype for drilling and producing oil and gas over water – the piled platform.

What's more, successful Caddo Lake development stimulated similar plans for oil fields known to extend below lakes and bays along the Louisiana-Texas Gulf Coast. One standout example is Humble Oil & Refining Co.'s Goose Creek field near Houston, which was developed onshore with land equipment and offshore with Caddo Lake-type wooden platforms supporting producing wells in lakes connected by tidal flow to the upper reaches of Galveston Bay.

Milestones

1500 Leonardo da Vinci sketches machine for boring wells.

1806 Spring pole cable drilling developed in US.

1807 Cored trees used for casing in recovery of salt brine.

1844 Fluid circulating rotary well drilling patented (England – Robert Beart).

1845 Circulated fluid used to remove drill cuttings for first time.

1859 Drake well completed for sole purpose of producing oil.

1860 Fluid circulation rotary diamond coring drill developed (France).

1878 First bulk oil tanker begins operation (Caspian Sea – Nobel).

1891 First ocean-going tanker launched.

1897 First hole drilled from wharf (Summerland, California).

1901 Spindletop discovered (Beaumont, Texas, at 1,100 ft).

1911 Platform drilling begins on Louisiana's Caddo Lake.

1922 Oil discovered in Venezuela's Lake Maracaibo.

1922 Acreage offshore Baku drained to accommodate drilling.

1924 First platform erected on Venezuela's Lake Maracaibo.

1925 Production begins on artificial island in Ilyich Bay (Caspian Sea).

1927 Concrete pilings used under platform (Lake Maracaibo – Raymond).

1928 Patent awarded for submersible barge drilling unit (Giliasso).

1930 Trestles built into Caspian Sea for oil drilling.

1934 Drilling engineers begin serious exchanges of technology.

1937 First successful well in Gulf of Mexico (Creole – Superior/Pure).

1938 First well drilled offshore Texas (Galveston Bay – Standard Oil).

1939 First well drilled on concrete base offshore Brazil.

1945 First offshore US lease sale.

1947 Platform built 9 mi offshore.

1949 44 exploratory wells in Gulf of Mexico.

1952 First pipelay barge.

1954 Brazil's Petrobras begins offshore exploration.

1954 First jackup drilling unit.

1954 First offshore pipeline laid.

1954 Offshore Magazine established.

1955 Platform installation depth reaches 100 ft.

1956 First drillship launched.

1958 First commercial helicopter service in US Gulf.

1959 Offshore rotating hoists lift 800 tons.

1962 Fixed platform depth reaches 200 ft.

1962 First semisubmersible.

1964 Second generation semisubmersible.

1965 First fixed platform in North Sea.

1967 Diving depths reach 600 ft.

1973 Investment in US Gulf rises to $16 billion.

1975 Reel pipelay exceeds 1,000 ft water depth.

1979 Fixed platform depth exceeds 1,000 ft.

1980 Kielland semi accommodation unit capsizes (Ekofisk Edda).

1980 Louisiana Offshore Oil Port completed.

1981 Area-wide leasing begins in US Gulf.

1981 First offshore horizontal well drilled.

1982 Ocean Ranger semi drilling unit sinks (Hibernia – Odeco).

1983 First TLP operational (Hutton/Conoco).

1984 Offshore production surpasses 14 MMb/d (26% of total world).

1985 Demand for mobile drilling units peaks at 530.

1985 Oil prices drop to $10/bbl.

1987 Demand for mobile drilling units drops to 275.

1988 Bullwinkle's structure is the world's tallest pile-supported fixed steel platform.

1988 Drilling water depth reaches 7,512 ft.

1988 Fixed production platform installed in 1,353 ft water depth.

1988 Piper A platform destroyed (UK – North Sea).

1989 Platform removals outpace installations in US Gulf.

1991 Brazil completes well in 2,360 ft water depth.

1991 Supercomputer workstation processes 3D seismic model.

1992 Sleipner A condeep sinks in Norwegian fjord.

1993 Layaway subsea tree for 6,000 ft water depths (Petrobras).

1994 Auger TLP in the Gulf of Mexico is the first floating production facility.

1995 Conoco installs first concrete-hull TLP on Heidrun field in the Norwegian North Sea.

1996 First spar production unit installed.

1997 First offshore underbalanced well drilled with Williams rotating control head.

1998 BP drills extended reach well beyond 10 km on Wytch Farm M-11 well.

1999 Transocean introduces dual-activity drillship.

1999 Largest Gulf of Mexico discovery (Thunder Horse at 1 Bbbl).

1999 Deepwater oil production in the Gulf of Mexico exceeds shallow-water oil production.

2000 Oil and gas produced in 6,157 ft water depth Offshore Brazil.

2001 Floating rig drills in 9,687 ft water depth.

2001 Cameron installs world's first 15,000-psi working pressure subsea christmas tree.

2004 Na Kika will become the deepest Gulf of Mexico production at 7,600 ft water depth.

2004 Offshore Magazine reaches its 50th year.

TIME CAPSULE

FEBRUARY 1961

Shell makes first underwater completion in Gulf

In 1961, Shell unveiled a new technique to place equipment that controlled the flow of crude oil and gas on the bottom of the sea over a completed well. Although it was successful in the initial application, the technique later underwent further development. That original vision launched the industry into deepwater drilling and completions that eventually led to 10,000 ft of water. Offshore reported the event:

"A dramatic new technique for producing oil from wells under offshore waters has been announced by Shell Oil Company. The word 'under' must be stressed, for Shell Oil Company has made the first underwater completion by the oil industry in the Gulf of Mexico, the world's largest producing offshore areaU Operations involved in bringing in the well and subsequent production operations are all performed by remote control from the surface of the water, without the use of diversU The first ocean-bottom well to be completed using Shell's new technique was brought on last December 19, 1960U The OCS 407 No. 7 well is located in 56 ft of water in the West Cameron block 192 field, 35 miles off the coast of LouisianaU The well is 8,300-ft deepU Reports are that it was completed for 288 b/d of oil, based on a 12-hour test, but this has not been confirmed." Offshore, February 1961.

Summerland becomes 'cradle' of offshore

Many petroleum industry historians trace the origin of offshore drilling and production to Summerland, California.

In 1897, the community's founder, Henry L. Williams, a spiritualist and sometime wildcatter, determined from local tar seeps and natural gas vents that oil existed beneath the area. A number of land wells were dug in the area – some productive, others not.

But Williams also noted that because the most productive wells were drilled near the coastline, it was a good bet that Summerland's producing formations extended westward beyond the shoreline, extending beneath the Pacific Ocean. Williams himself eventually built several wooden piers out into the water, each projecting 450 ft from the shoreline. At piers' end, water depths reached 35 ft or so.

During the next three years, Williams erected 20 drilling derricks atop the piers to allow land rigs to drill wells over the water, with power generators and other support equipment installed back on shore. To drill wells, Williams and other local producers used first cable tools, then rotary rigs, to drill to the producing sands about 450 ft below. By 1900, 11 piers had been built at Summerland, the longest of which jutted 500 ft offshore.

The most prolific Summerland wells produced only about 75 b/d of oil. Average wells yielded only about 2 b/d. So, by 1902, production had peaked and had begun to decline rapidly. Meanwhile, the search for oil in California had moved eastward to the great San Joaquin Valley play in Kern and adjacent counties. By the 1930s, most of the Summerland pier wells had been abandoned. By the mid-1940s, the last of the piers themselves had been destroyed by Pacific coast storms.

Other venturers copied the pier and derrick technique elsewhere along California's coastline. At one field near Elwood, just north of Los Angeles, several piers extended 1,800 ft offshore into 35 ft of water. Similarly, piers also serviced the offshore extension of the Wilmington field, also very near Los Angeles.

In terms of production, California's pier-based offshore oil fields paled in comparison to the Kern County play and other oil booms in the Golden State; however, they did usher in an exploration phase that gave rise to over-water drilling and production activities in other areas of the country.

In addition to being the first venture offshore, perhaps the greatest contribution to the industry to come from the pier drilling was introduction of the drilling conductor – a short, large-diameter pipe pounded into the sand of the sea bottom through which drilling was conducted. Once purged of water, the conductor allowed land-type wellhead equipment to be used offshore. To this day, all offshore drillers include conductor pipe in marine well construction.

JUNE 1964

Shell hits off Borneo after costly search

Shell acquired licenses to Brunei's offshore region when the country's boundaries were extended to include the continental shelf in 1954. The first well drilled off Malaysia in 1957 was drilled from a fixed platform. That well was a duster, but Shell was determined to explore the region's offshore. The company continued its run of bad luck, drilling in the South China Sea for seven years before discovering the Southwest Ampa oil and gas field in June 1964.

null

The Ampa discovery, 7 mi offshore, was made possible in great part by an innovation in offshore drilling that produced the Sidewinder, an offshore drilling rig stabilized by outriggers and designed to drill to 20,000 ft in 600 ft of water. Zapata Off-Shore Co. moved the Sidewinder from the Gulf of Mexico to join the search for oil in Malaysia in the summer of 1963. When success finally came, Offshore reported the event:

"Brunei Shell Petroleum Company has discovered what appears to be a major field off Brunei (British Borneo) after seven bleak years of exploration in the South China Sea.

The discovery, about 7 mi offshore from the Seria field, encountered oil and gas in a series of sands below 8,000-ft. and reportedly tested at the rate of 4,000 b/d from the top sand alone. Zapata Off-Shore Company's floating drilling vessel Sidewinder drilled the test to depth of 9,480-ft. in about 90 ft. of waterU. Shell reportedly plans to bring at least one more mobile unit to Brunei and to erect a 120-ft. wide by 165-ft. long 18-well drilling platform in the discovery area." – Offshore June, 1964

JUNE 1970

Phillips reveals Ekofisk discovery – first oil in North Sea

In 1970, Phillips released definitive information on a previous test and a follow-up well in the Norwegian sector of the North Sea. Although still undefined in extent or significance, it was clearly a landmark event. Geologists had long maintained that the North Sea would yield no oil. Phillips challenged conventional wisdom (a leading geologist of the time had declared that he would drink all the oil found in the North Sea), and the result launched a new era in offshore exploration. Offshore reported the event:

"A new petroleum province – one that yields low sulphur crude oil – now appears certain in the North Sea. Phillips Petroleum, operator for a group, has confirmed the big oil strike located in a hostile far-out area off Norway. Though the precise magnitude of the reservoir is not yet known, there is decisive evidence it will be prolificU. In confirming the discovery, Phillips reported the well, Ekofisk 2X – flowed at rates up to 2,000 b/d U work will continue with Ocean Drilling and Exploration Co.'s drill-barge Ocean Viking U" – Offshore, June 5, 1970.

Russia begins Caspian Sea development

While most of the earliest development of offshore drilling and production technology centered in the Western Hemisphere, the ideas associated with developing over-water oil and gas reserves were not.

Quite independently, far to the east in the fledgling Soviet Union, a similar birth of offshore technology occurred in the area of Asia Minor that surrounds the Caspian Sea, a giant salt lake the size of the state of New Mexico and the world's largest inland body of water.

In the early 1900s, the Soviet state oil ministry, anxious to add more production from oil fields exploited for centuries along the western coast of the Caspian Sea, made plans to fill shallow bays in the sea itself with rocks in order to conduct land-type rotary drilling operations. But political events and the area's remoteness served to stall the bay-filling operation for more than a decade. By the 1930s, when the idea was deemed impractical, the Soviets instituted a trestle/platform development plan that allowed over-water drilling far out into the lake. By 1941, when the German army invaded Russia, aiming one of its main thrusts at the Caspian area to seize much-needed oil supplies, hundreds of miles of wooden and steel-member trestles and platforms threaded their way around the lake in the vicinity of Baku, which is today the capital of the Republic of Azerbaijan.

The Caspian Sea today remains an important oil-producing province, with leading edge exploration and production equipment extending development into deepwater horizons near the sea's center. Oil and gas production is shared by multinational companies with the governments of several former Soviet republics that border on the Caspian. Iran, across the sea, has never fully developed its huge share of Caspian Sea acreage, though the petroleum potential there is not considered as significant as that of the "European" side.

NOVEMBER 1977

Cognac platform installed in deepwater Gulf of Mexico

In 1977, the Shell-operated Cognac discovery moved to the deep part of the line. The three-unit platform attracted headlines with its installation in 1,025 ft of water – at that time, the deepest yet. The Pacesetter 11 drilled the Cognac discovery well in the Gulf of Mexico in July 1975 in 936 ft of water. Eleven additional exploration wells were drilled, and reserves were estimated at 100 MMbbl and 500 bcf. The partners developed Cognac on Mississippi Canyon blocks 108, 151, 194, and 195 with a fixed steel platform installed on Mississippi Canyon block 194 in 1,025 ft of water. At the time of its installation, Shell-operated Cognac was the world's tallest and heaviest steel offshore structure. Field partners acquired the leases in March 1974 for $295.3 million.

null

McDermott Inc. in Morgan City, Louisiana, built and installed the 61-wellslot platform in three separate units: the base, middle, and top. The base was launched on July 25, 1977, and the middle and top sections followed in 1978. In September 1979, oil and gas production began from temporary facilities and shifted to permanent production facilities in March 1982. The partners initiated a major field redevelopment program in July 1989, and 20 redevelopment wells were drilled. Offshore reported the installation of the deepest platform to date:

"Piledriving the base section of Shell's Prospect Cognac platform jacket off the mouth of the Mississippi River was completed in early October, two months ahead of schedule. The driving operation was delayed once in late August by two hurricanes.U The three sections of the platform will be mated underwater using a docking procedureU. Initial production is expected to be from 20,000 to 25,000 b/d." – Offshore, November 1977

Maracaibo parasite ushers in concrete pilings

While the concept of offshore oil and gas development might generally be pinned to American ingenuity and sense of purpose, not all offshore innovation and progress took place in the US. Oil development in Lake Maracaibo, Venezuela, began in the 1920s in much the same way as it did at Caddo Lake. Big oil discoveries in the rainforest area surrounding the lake resulted in most area leases being scooped up by various international companies operating in partnership with Venezuela's state oil ministry.

Royal Dutch/Shell, for one, sensed that the fields found onshore extended beneath the lake's shallow, brackish waters and subsequently obtained large over-water leaseholds. Drawing on experience stemming from California and Caddo Lake operations, Shell and subsequent lessees brought wooden-piled platform development to Lake Maracaibo.

Exploitation of the lake's oil reserves might have been rather routine, were it not for the dreaded teredo, an intrusive shipworm that had plagued the marine industries since ancient times. The bothersome parasites could bore and chew through wooden pilings supporting a Lake Maracaibo drilling platform in a matter of months, before companies could produce enough oil to make a profit from the platform. The companies tried importing creosote-treated pine pilings from the US, but while this antidote proved effective, it also was expensive and, ultimately, uneconomic.

By coincidence, the Venezuelan government had contracted with Raymond Concrete Pile Co., a US firm, to build a seawall on the lakefront near the oil fields. The project was large enough for Raymond to install a concrete plant to manufacture the piles necessary for the massive seawall.

The serendipitous use of concrete piles to replace wooden ones used by several of the oil companies served to outfox the teredoes, and soon oil producers were using concrete in place of wood for pilings. Then, they added steel heads to allow for faster pile-drive installation. That, in turn, brought on the addition of both steel and wire rope braces to aid in platform stability and the use of prefabricated concrete deck sections upon which first rigs, then production equipment, were installed.

During the next 30 years, Lake Maracaibo operators erected 900 concrete and steel platforms in the lake. By the 1950s, they were using hollow, heavy walled pre-stressed concrete piles with extremely wide diameters upon which similar pre-stressed concrete decks, piers, and walkways were erected. The idea of employing wider-diameter piles (up to 54-in. outside diameter) served as a model for the all-steel pilings later incorporated into offshore platform jackets developed for use in the Gulf of Mexico and other offshore provinces in deeper water.