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Coastal Zone information Center 46 41 if 6 414 4 6 4 141 1114; & 4 14 4 4 41 A dr Exxon Background Series LU I nownON The offshore search for oil and gas HD 9502 (becond edition) 8/75 .U52 R9 5 1975 TABLE OF CONTENTS INTRODUCTION ............................................................................................................2 THE NEEDS .....................................................................................................................2 THE DIFFICULTIES .....................................................................................................3 WORLD'S ESTIMATED OIL RESERVES YEAR-END 1974 (Chart) ...........................................................................................4 WORLD OIL PRODUCTION 1963-74 (Chart) ............................................................5 THESEARCH ..................................................................................................................6 DRILLING OFFSHORE ................................................................................................7 WORLD MAP ....................................................................................................................8 TOWARD SAFER OPERATIONS ............................................................................... 10 THE ACCIDENT RECORD .......................................................................................... 11 OFFSHORE RIGS AND WELLS DRILLED WORLDWIDE 1963-74 (Chart) ................................................................................. 12 CONTAINING AND CLEANING SPILLS ................................................................ 13 NEW TECHNOLOGY AND RESEARCH ................................................................. 14 ONSHORE PROTECTION ............................................................................................ 15 SUMMARY ........................................................................................................................ 16 C@@_ Library AXrjqTq 3SZ) ;o Aj@edozd U DEPARTMENT! OF COMMERCE NOAA COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE F ',@TON . SC 29405- 2 6 P_ C.Q CP A background paper prepared by the Public Affairs Department of Exxon Corporation in cooperation with other Exxon Departments for Exxon and affiliate use. (second edition) tP INTRODUCTION 2 The search for oil and gas to satisfy the Africa and South America, in the Mediterra- world's growing energy demands has been nean, in Australian and Indonesian waters, moving offshore increasingly in recent years. and in the Persian Gulf -to name the princi- This trend, plus widely publicized accounts of pal areas. Wells have been or are being drilled some blowouts and spills resulting from drill- in the waters of at least seventy countries- ing and producing activities, has given rise to more than half the nations of the world-and public concern about the possible impact on petroleum is being produced offshore in at the offshore environment. In view of this con- least thirty of these countries 4. Currently, cern and the much higher costs of offshore more than 480 rigs are in operation around drilling as compared with onshore work, why the world, drilling wells in waters as deep as does the petroleum industry persist in the 2,000 feet and at distances as f ar as 165 miles offshore search for oil and gas? The reason is from shore. simple: that's where much of the remaining undiscovered petroleum is believed to be, and Drilling offshore normally is more difficult the world needs the energy. and expensive than drilling wells onshore. While there is no greater assurance of suc- Offshore drilling is not at all new. It has been cess, there is more opportunity for finding going on for several decades and has resulted large fields capable of significant production in the discovery of large quantities of oil. In in the undrilled offshore basins than in the 1974, offshore areas accounted for about 10 mature, well-drilled onshore producing areas. million barrels daily, or about 18 percent of the worldwide crude production of about 58 million barrels daily Offshore proved crude oil reserves are estimated at 162 billion barrels THE NEEDS and represent 23 percent of the world total. To understand fully the reasons for moving Offshore drilling in the United States began offshore, we must look at the energy supply- off California as early as the end of last cen- and-demand picture today. tury and has been widespread there and in the Gulf of Mexico for the past quarter of a World energy consumption rose about 80 per- century. To date, more than 19,000 wells have cent between 1960 and 1973 and is still been drilled in U.S. waters. increasing. This growth in energy consump- tion is basic to the desire of the nations of the Offshore activity overseas began later than in world to develop their economics and raise the United States, but exploration and drill- their living standards. While the bulk of the ing now is conducted in all corners of the energy from oil is consumed today in the globe, with extensive drilling in Lake Mara- developed countries in North America and caibo in Venezuela, in the North Sea, off West Europe, and in Japan, consumption is increas- ing in all parts of the world. The search for oil and gas A glance at the world's estimated oil reserves is moving offshore increas- shows that the Middle East towers above all ingly. other regions. Africa's reserves are put at 68 billion barrels; Central and South America Offshore production of 10 have 41 billion barrels; the United States has million barrels a day is 35, including an estimated 10 billion barrels about 18 percent of the in Alaska; Europe, 26 billion; Asia and Aus- world's crude oil total. tralia, 21 billion; Canada, 9 billion barrels. But the Middle East has 404 billion barrels of esti- Wells have been drilled in mated reserves, something like two-thirds of waters of at least 70 all the estimated reserves in non-Communist countries, and production countries. (Although definitive figures are is occurring in about 30. difficult to obtain, the reserves of Communist nations have been estimated at 111 billion barrels.) THE DIFFICULTIES Much of these reserves-in fact, most of those One of the greatest handicaps of offshore 3 in Europe, Asia, and Australia-are in off- drilling and production, of course, is the shore areas. weather. To the usual outdoor challenges of wind, rain, snow, and ice are added tides, high Obviously, most of the world will have to con- waves, fog and in some locations, hurricanes, tinue to depend upon the Middle East and earthquakes, ice floes and icebergs. 'Not only North and West Africa for the greater part of can these hamper operations, but also they its oil supply. The United States has been can threaten the safety of the workers and importing increasing quantities from those the survival of the equipment. Storms can regions. come up quickly in some parts of the world and can bring winds of more than 100 miles Only by major new discoveries in other areas an hour and waves 80 or more feet high. of the world can that dependence be lessened. Equipment must be secured quickly, and in Oil and natural gas have become increasingly some cases crews must be evacuated to the more difficult and costly to find on land. But safety of shore locations. Storms can force a offshore areas are estimated to have impor- halt in drilling, as well as in production activi- tant potential reserves of oil and gas that as ties and require extensive precautions yet have been only partially tapped. against equipment damage and the threat of oil spills. Naturally, the offshore search for oil and gas must be conducted with f ull regard for the To the weather are added other natural diffi- environment. In this respect, the industry's culties of an offshore well site, particularly record in offshore operations, particularly in when it is in waters several hundred feet U.S. waters, probably is better than is gener- deep. A variety of rig types equipped with ally recognized. But the challenges are many specialized and highly sophisticated equip- and meeting them with minimum damage to ment has been developed to meet the varied the sea environment demands continuing demands of offshore drilling. Delivering the efforts. supplies and transporting personnel to remote and physically hostile environments raise logistical challenges demanding the rn best in marine equipment and operations. Offshore exploration and production are very expensive. Large amounts are paid by explo- ration companies to governments to secure offshore leases. Capital and operating expen- ditures for offshore oil exploration and pro- duction throughout the world are generally much greater than the expenditures required for exploration and production onshore. The Joint Association urvey yt e can Petroleum Institute and others in 1975 lists average drilling cost (1973) of a U.S. off- shore exploration or production well as $650,000, as compared with approximately $98,000 for the average onshore well in the continental United States, although part of the higher cost of wells offshore is explained 0 by their generally greater depth. Costs have risen since 1973. Once anchored in place, the semi-submersible isused to drill wildcat or exploratory wells in depths about 1,000ftet. WORLD'S ESTIMATED CRUDE OIL RESERVES BILLIONS OF BARRELS YEAR-END 1974 425 403.8 400 375 350 - 325 - 300 - 275 - 250 - 225 200 175 150 125 111.4 100 - 75- 68.3 50- 35.3 40.6 25.8 25 9.4 U.S.A. CANADA EUROPE ASIA CENT. & AFRICA MIDDLE COMMUNIST PACIFIC SO. AMER. EAST WORLD Source: Oil and Gas Journal, December 30, 1974. World total of 715.6 includes estimated 162 billion barrels offshore. 25 it 9.4 21.0 The cost of an exploration well in the North which nearly fifty nations now subscribe, 5 Sea is about four and one-half million dollars. holds that coastal state jurisdiction over A large production platform in the North Sea seabed resources extends at least to a depth capable of having 35 to 45 wells costs from 175 of 200 meters (ca. 650 feet) and beyond to the to 200 million dollars. Completion of produc- limit that technology permits. But who is to ing wells and transporting the oil or gas to exercise authority beyond the limits of shore also are costly. coastal state jurisdiction? These and other complex legal and political issues f acing off- In 1970, a contractor's charge for an explora- shore activities are yet to be resolved. tion drilling vessel operating in the North Sea and many other offshore areas of the Little exploratory drilling has taken place world was 20 to 25 thousand dollars a day. This beyond the 200-meter depth, and most off- cost since, like that of many other materials, shore drilling for oil or gas has occurred at supplies and services, has more than doubled, distances less than 100 miles offshore. Still, it and such vessels now cost oil companies 50 to is clear that the search is moving farther off- 70 thousand dollars a day. shore and into deeper waters. Currently, exploratory permits are held for areas with Thus, as the offshore share of total oil pro- water much deeper than 600 f eet, and have duced increases, the cost per barrel of oil is been issued f or areas with water as deep as likely to rise. 13,000 feet off eastern Canada. An impediment to offshore exploration and production is the question of jurisdiction.. The 1958 Convention on the Continental Shelf, to WORLD.OIL PRODUCTION--1963-1974 MILLIONS OF BARRELS DAILY 60 World Total 50 00"Man" 40 000 --" Non-Communist World 30 20 Offshore Total- 10 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 low WIN Source: Industry Reports. Note: Natural gas liquids, which comprise about 5 percent of each total, are included. THESEARCH 6 The search for oil or gas offshore, as that on A few years ago Exxorf" invented a device for land, begins with seismic surveys, but with this purpose to replace the use of dynamite in a special water technique that can cover a creating shock waves underwater. A mixture greater area in a shorter time. Sound waves of propane and oxygen is ignited inside a rub- are generated to travel downward deep below ber sleeve. Rapid combustion inflates the the seabed. These waves are reflected from sleeve like an instant balloon and produces a successive rock formations back to the sur- seismic pulse. The device is not injurious to face where they are picked up by detecting marine life and is much more economical to devices and recorded. By measuring the time use than dynamite. intervals required for the impulses to travel down and back, and correcting and interpret- *The term Exxon as used in this publication refers not ing the data, a geophysicist can determine only to Exxon Corporation, but also to companies affili- the general configuration of the formations ated with Exxon Corporation. that lie underground, and identify possible traps in which oil or gas might have accumulated. The highly mobile drilling ship can drill wells in water depths of more than 2,000.feet. DRILLING OFFSHORE If geophysical and geological data indicate Finally, there is the drill ship. This is a ship 7 that there's a possibility of finding oil or natu- with a hole through the hull for drilling. It is ral gas under the ocean floor, the next step is usually moored in the same manner as a semi- to drill an exploratory well. To do this, mov- submersible; however, drill ships and semi- able rigs are used. About 290 of these are at submersibles designed f or use in deep water work today around the world, one-fourth of supplement or replace the mooring system them in U.S. waters. Three general types of with thrusters. Drill ships have been used in mobile rigs are used in exploratory drilling. water depths greater than 2,000 feet, and One is the self-elevating rig which can be new ones under construction are designed for towed to the location. At the site, the legs are operations in water up to 6,000 feet deep. lowered to the seabed and the platform is jacked up to a safe level above the sea. The Drilling an offshore well with these mobile maximum water depth in which jack-up rigs rigs is in many respects like drilling on land, are used is about 350 feet. but it is more demanding and costly because of the environment. It is an around-the-clock A second type of rig is known as semi-sub- operation. Elaborate guidance systems and mersible. Some of these actually can sit on the blowout preventers installed on the ocean bottom in shallow water, but they are more floor are combined with the latest drilling frequently used in a partially submerged technologies to minimize the danger of blow- position, moored by anchors, much like a ship. outs and to assure safe and effective drilling. Mooring lines may extend a mile or more. At The blowout preventer is installed on the the end of each line is a massive anchor, wellhead after the first string of casing is set weighing as much as 40,000 pounds. An elabo- in the hole. This important safety device can rate acoustical system monitors the position close off the space between the drill pipe and of the rig in relation to the well. One of these the casing in a matter of seconds if unex- rigs can displace as much as 40,000 tons and pected high pressures are met. cost more than $50 million to build. About 70 are in operation. Several semi-submersibles If exploratory drilling finds oil or gas in have drilled wells in water 600 feet deep, and amounts that can be produced economically, semi-submersibles designed f or depths of permanent platforms are installed to drill 2,000 to 3,500 feet are under construction. development wells. These platforms are huge, fixed structures that can be installed in hundreds of feet of water. Like the mobile Weather and deep water rigs, they are large enough to contain living bring major challenges to quarters for the work crew, a helicopter land- offshore operations. ing pad, storage space for supplies, and room for the drilling and production equipment. Seismic surveys, one of The typical platform is so designed that the first steps in off- thirty or more wells may be drilled from it by shore exploration, are directional or angular drilling. Thus, wells aided by a pulse device drilled from a single platform may extend developed by Exxon. over several hundred acres as measured at the bottoms of the holes. More than half of the almost 500 rigs in opera- tion offshore are mobile. Wells have been drilled in water depths greater than 2,000 feet. 90. 120. 150. Mo- 150. 120. 8 World Map Continental Shelf Areas to 200 Meters v,' E A U F 0 R T W MI F-- Vff, Ir-h KFU V RE", N 0 R T H W C F I C 0 C E A P A 1 8 D I E A S 0 U T H P A C I F I C 0 C E A N 5i ", 10 115 mv lo. so- 15o. 120- so- so- 50- so- so- so- AM //4 A R C T I C 0 C E A N 11"A N .7- 'e "i"@ @t' w v7"Fa, .@Ti 0. Okh 'g do <P ff qg' RE 9 N AND ss @'s 11% 1 Is 'k; MAIN-,, ON TO- A q Ul, $ n' N 0 R T H Uo A T L A N 0 C E A N iR"..4 n@Z T o. -tej, Me @RIII'Y-'I!r'rP IF 01 TT"T Pf FT r" A ff" '-T4 1, VA, U -111-1 @Qw -k Z' 1 4 A IN I N D I A NJ FIN, A o c N S 0 U T H 30- A Vol ;iiz 5 T L A N T I C eMajor Areas of Offshore 0 C E A N Activity 1974 Offshore Areas to 200 Meters: b Approx. 9.9 Million Sq. Miles offshore Areas to 300 Meters: Approx. 10.8 Million Sq. Miles Source: L. G. Weeks, Offshore Magazine, and Oil & Gas Journal Adapted from Offshore Magazine 17k 1 go. so- 30- o. TOWARD SAFER OPERATIONS 10 The design and construction of offshore struc- ing valves or other control equipment. If tures are part of the petroleum industry's existing equipment cannot be used, replace- efforts to protect the ocean environment. ment of control equipment may be tried. In Extensive studies have been made of the some cases, a heavy casing with valves is effect of water depths, tides, shifting cur- lowered into place over the wellhead, and the rents and wave and wind forces during flow of oil or gas continues through the storms to ensure that offshore drilling and valves. When the casing is securely fastened, production platforms can withstand these the valves are closed one by one until the well elements. is under control. These control methods some- times can be carried out in a matter of a few The offshore structures now in use in deep hours. If for any reason the wellhead cannot waters of the Gulf of Mexico have been built be capped, the usual procedure is to drill a to endure winds up to 140 miles an hour and relief well. To do this, a rig is moved to a waves of more than 60 feet. Platforms operat- nearby spot and a hole is drilled at an angle ing in the Cook Inlet of Alaska have with- until it comes close to the bottom of the blow- stood a special challenge -rafted ice floes six out well. When this is done, mud is pumped feet thick. During the winter these floes are into the underground reservoir under high carried in and out of the inlet by swift cur- pressure, stopping the flow. This is a difficult rents and thirty-foot tides. In the North and time-consuming procedure which can Atlantic, operators must be on the alert for take several weeks. icebergs. Canadian companies have towed icebergs to keep them from drif ting into Most important, of course, is prevention of floating drilling operations, and have used blowouts or other accidents, and to that end drill ships that stay on location, using thrust- Exxon established one of the world's first ers instead of anchors, so that, after making well-control schools. This unusual program is the well safe, the ship can move out of the way centered around a mile-deep well on the vast quickly if an iceberg approaches too closely. King Ranch in southern Texas. For the past seven years, drilling superintendents and Most offshore producing wells are equipped contract crews from Exxon affiliates all over with a sub-surface safety valve. The excep- the world have attended sessions there to tions generally are wells with low-pressure learn and pra@tice the latest techniques in flows deemed not to be hazardous. Installed in blowout prevention and control. Other com- the well itself below the ocean floor, the valve panies now offer similar programs, and Loui- is designed to shut down production automat- siana State University, the University of ically when there is a sudden release of well- Oklahoma, and the University of Southwest- head pressure or when the flow rate increases too rapidly. If a hurricane, for example, were to damage the normal producing system, the Huge, fixed platforms valve would close to stop the flow of oil or gas. permit development drill- Regular checks of these devices are made to ing and production of more assure proper functioning. New wells in U.S. than 30 wells from a waters are being equipped with an improved single structure. down-hole safety valve controlled from the surface. In areas where formation solids Sub-surface safety valves (usually sand) are produced along with the oil, are used to stop the flow another safety device, called an erosion in producing wells if probe, is used. This system senses sand pro- there should be a mechan- duction and closes in the well before the abra- ical malfunction. sive solids can cut through surface flowlines. Despite all precautions, blowouts do occur occasionally. There area number of ways to deal with a blowout, but the operator nor- mally tries first to shut off the well with exist- THE ACCIDENT RECORD ern Louisiana conduct well-control training The U.S. National Academy of Sciences courses open to drilling personnel of the estimated in a study published in 1975* whole oil industry Blowout prevention train- that 80,000 metric tons of oil enters the ing programs are conducted in other coun- oceans each year from offshore drilling and tries, too. For example, Exxon conducts producing operations. This is less than 2 approximately ten seminars on blowout pre- percent of the total of oil entering the vention each year for overseas affiliate and oceans from all sources, including marine contractor personnel wherever Exxon is drill- transportation, coastal refineries, munici- ing for oil. The company also conducts semi- pal and industrial wastes, urban and river nars on the latest equipment and techniques runoff, and natural oil seeps. Of the 80,000 of floating drilling. tons from offshore operations, one-fourth is estimated to be from minor spills of 50 In addition to its extensive training activi- barrels or less, and from discharge of oil ties in blowout prevention, Exxon is conduct- field brines during normal operations. The ing an industry-funded program to study the remaining 60,000 tons a year is lost into blowout preventer equipment commonly the water in spills of more than 50 barrels. used in floating drilling. The object is to make this vital equipment even more effective. While blowouts have occurred, both in U.S. waters and abroad, they nevertheless have been rare. In U.S. waters, the oil industry has drilled more than 18,000 wells since 1948, and several thousand are in produc- tion. During this 26-year period, only four blowouts have posed any serious pollution threat, and only one of them resulted in serious pollution to the beaches. This was the Santa Barbara Channel blowout of January 1969, that spilled an estimated 75,000 barrels of crude oil into the water in ten days, and caused the death of many birds. As serious as this blowout was, investigations a year later by a research team from the University of Southern California found that the spill caused no apparent lasting damage to marine life or the beaches. Since beginning a regular program of off- shore operations in the United States 26 years ago, Exxon has drilled nearly 1,500 offshore wells. It now is producing oil from about 500 wells on offshore platforms. Throughout the company's operations, it has had no oil spills f rom well blowouts classified so large as "moderate"-i.e. 240 barrels or more.* * *Petroleum in the Marine Environment, Washington, D.C. 1975. *U.S. authorities define a major spill as anything over 2,400 barrels; a moderate one is between 240 and 2,400 With elevator legs, thejack-up rig can be barrels; and a minor spill is one involving less than 240 floated to location and then raised, orjacked barrels. The Water Quality Improvement Act of 1970 up, to an appropriate height above water. This requires that all spills be reported to an appropriate U.S. rigs utility normally is limited to water government agency. about 350feet deep. 12 In the Gulf of Mexico, where the largest During 1973, the U.S. Coast Guard number of offshore rigs are in operation, reported about 1,955 spill incidents at U.S. the oil industry has experienced four offshore production facilities, with a total serious blowouts and fires since December release of about 20,000 barrels of oil into 1970, two of them requiring several weeks the marine environment (an average of to bring under control. The largest blowout about 11 barrels per spill). But there is little and fire in U.S. coastal waters occurred in evidence of sustained damage to marine December 1970, on Platform B in South life, or significant or lasting pollution of Timbalier waters off Bay Marchand, Loui- the beaches. siana. Four men were killed and thirty-two injured in the blowout and fire that was not Parenthetically, it is worth noting that at totally extinguished for more than four least one unanticipated benefit has months. Immediately after the accident, resulted from offshore drilling production. the operating-company mobilized a fleet of Despite apprehensions about possible fire-fighting and pollution-control vessels harmful effects on fishing grounds, the off- and a force of 650 men to extinguish the shore platforms have proved attractive to blaze and contain the oil. Four rigs drilled the fish, which seem to be drawn to the ten relief wells into the producing forma- underwater structures by the barnacles tions of the burning wells before they were and other small marine life that cling to all "killed" Despite the massive control the beams, and waters around the plat- measures, it was not until April 1971 that forms have become favorite spots for the blowout was brought under control fishing. totally, although the main well had been killed within a month. Rigs AVAILABLE OFFSHORE RIGS AND WELLS DRILLED--WORLDWIDE Wells 600 3000 500 2500 400 Al 2000 300 e*100 Opp _.00000@ 1500 2000000 1000 100 500 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Source: Offshore Magazine and Industry Reports. CONTAINING AND CLEANING SPILLS Essential to the protection of the marine Exxon initiated a contract with Battelle- 13 environment is the availability and use of Northwest in 1970 to determine the long- containment and clean-up equipment. Sev- range effects of oil spills on the sea and, in eral types of booms for containing the oil, and particular, on marine ecology. In 1971, the numerous skimmers and other recovery ves- American Petroleum Institute (API) sels for picking it up from the water have expanded this important effort at Battelle- been developed by the industry and govern- Northwest as well as at other research insti- ments. The use of most of these in heavy seas tutions. In these studies, marine organisms, is limited, but new, equipment is being devel- of many different species were exposed to oped to operate more effectively in adverse different crude oils and petroleum products. weather and sea conditions. A "bottom ten- It was established that once an oil spill has sion" boom developed by Exxon is marketed passed, organisms cleanse themselves quickly by two manufacturers. This unit is designed of whatever oil contamination they may have to contain oil in waves as high as six feet and incurred. Thus, these studies show that it is can withstand twenty-foot seas and fifty- highly unlikely for such oil contamination to knot winds. Increased availability of contain- become concentrated by transfer through the ment and clean-up equipment in drilling and food chain. production areas will help assure control and recovery of any oil spills. An Exxon affiliate in 1971 commissioned a two-year study by Battelle-Northwest of the Cooperatives such as Clean Seas, Inc. and impact of petroleum operations on the fish- Clean Gulf Associates have been established ery resources on Lake Maracaibo. Analyses of in the United States to provide such equip- environmental samples-water, sediments, ment for emergency clean-up of spills. and fish-showed low concentrations of oil in Financed by Exxon and thirteen other oil lake waters, and no detectable accumulation companies operating in the Santa Barbara of petroleum-derived hydrocarbons in muscle Channel, Clean Seas provides on a stand-by tissue of selected commercial fish species. basis the equipment, materials, trained man- Natural processes of volatilization, biodegra- power, and technology to deal with spills. dation, and sedimentation were shown to be Clean Gulf, formed by 98 percent of the oil the major mechanisms by which oil is operators in the Gulf of Mexico, provides a removed from the surface waters. similar capability forthis area. Similar coop- erative efforts for quick reaction to oil spill In a recently completed two-year environ- emergencies are underway in the North Sea mental study in offshore Louisiana waters by and in other parts of the world. the Gulf Universities Research Consortium, no significant environmental degradation The U.S. Coast Guard, too, has oil spill clean- was detected in this prolific oil-producing up equipment available for rapid deployment area. from response centers at key locations. While intended for duty in U.S. waters, the Coast Guard Strike Teams have gained considerable experience on major foreign spills, among them tanker accidents in the Strait of Malacca and the Strait of Magellan. Research on oil spills-both clean-up and pre- vention-continues on many fronts. Exxon, for example, has developed new low-toxicity chemicals for containment and dispersal of oil, as well as improved equipment for separating oil from water. NEW TECHNOLOGY AND RESEARCH 14 Taking the search f or petroleum and gas ever- A "guyed towe?,'a new type of offshore plat- farther offshore and into deeper waters form for use in waters from 600 up to 2,000 requires both the extension of techniques feet deep, is being tested by Exxon in 1975, used for many years in shallower waters and with a 370-foot model to be installed in 300 the development of new technology suitable feet of water off the Louisiana coast. The test for drilling in hundreds of feet of water. structure is a one-fifth scale model of an oil and gas platform designed for 1,500 f eet of A striking example of this is the system water. The. platform is designed to sit on the devised by Exxon to develop a major new ocean floor, held in place by bridge cables field discovered in the Santa Barbara Channel attached to anchors surrounding it. Such a under 700 to 1,500 feet of water. The wells will guyed, or compliant, offshore tower (one be in water two to four times deeper than any which is allowed to "comply" or move with the now in production in offshore areas. Signifi- waves) may offer an economically attractive cant finds of oil have been made in the west- alternative to conventional platforms or sub- ern end of the channel, within a geological merged systems for use in water depths from structure named the Five-Mile Trend because 600 to 2,000 feet. of its distance from shore. Development plans involve the use of deep-water platforms In order to produce oil or gas in water depths and submerged production systems. beyond that feasible for surf ace-piercing platforms, Exxon is developing a Submerged The first drilling platform will be a real giant. Production System, or SPS. This installation Plans call for a towering eight-legged struc- consists of a number of underwater wells ture for a water depth of 850 f eet, by far the completed in a cluster. The wells are drilled tallest drilling platform in the history of the directionally from a floating rig through the petroleum industry. The Santa Barbara struc- template structure of the SPS, which is ture has been designed not only to absorb secured to the ocean floor. When they are pounding from storm waves, but also to with- ready for production, the subsea wells will be stand ground-shaking forces from a severe connected to the SPS manifold, and the oil earthquake. (Another company has reserved from them will flow through pipelines to a construction yard space for two platforms surface facility. suitable for 1,000 and 1,200-foot water depths for installation in the Gulf of Mexico. The The day-by-day operation of each SPS will prospect has not been drilled yet, however, involve advanced technology, including elec- and design work on the platforms is not tronics to monitor and "instruct" the unit, complete.) hydraulics to open and close valves, and safety devices designed to isolate malfunc- tions. In the unlikely event that a leak does Exxon is testing a pro- occur, oil-catching drip pans will collect the totype of the world's escaping oil. Simultaneously, an electronic tallest drilling platform sensor will activate a safety device, closing for installation in water down the wells and valves in that part of the 850 feet deep and Sub- manifold where the trouble lies. merged Production System for use in depths beyond After extensive testing on land, a full-scale fixed platform capability. three-well sPS prototype is being tested in an offshore oil field in the Gulf of Mexico 65 miles southeast of New Orleans. Production from A variety of containment three SPS wells will be routed to a nearby plat- and recovery systems form in the same field. Although the proto- has been developed, and type is installed in only 170 feet of water, the cooperatives have been SPS is designed for use in water depths up to established to deal with 2,000 f eet. Research is now under way to spill emergencies. extend the SPS capability to even greater depths. ONSHORE PROTECTION Onshore facilities supporting offshore opera- 15 tions also affect the environment. Proper planning and design, however, can minimize these effects. An example is the onshore facil- ity proposed by Exxon to treat the oil and gas produced from the Santa Barbara Channel. The inland site is hidden more than a mile from the coast up a canyon where there have been oil production and treatment facilities for nearly 50 years. The chosen plant site is 15 acres -completely surrounded by a 1,500 acre buffer zone-also owned by Exxon. Because of intervening hills and shrubbery, the plant will be out of view of passersby on the freeway more than a mile away. In compliance with local ordinances, the plant has been designed to prevent offensive or disturbing emissions and noise perceptible beyond Exxon's prop- erty line. At the projected sulphur removal effectiveness of 99.3 percent, it will emit sul- fur dioxide at approximately the same rate as a diesel locomotive. A three-well Submerged Production System (SPS) template structure to be secured on the oceanfloor When the wells drilled through this structure are completed, they will be con- nected to the SPS manifold, and the oil will flow through pipelines to the shore. SUMMARY 16 The coastal nations of the world recognize that their offshore areas can contribute to the energy that they and the rest of the world require if their economic development is to move ahead. The ecology of the sea and that of the entire ecosphere must be protected in the process. The petroleum industry believes it can be done. It can demonstrate to a concerned pub- lic that it possesses practical and effective answers both to supplying the required energy and to preserving the natural envi- ronment. The record of offshore drilling and production is not perfect, but it is respect- able, and with increased efforts in the future to operate more effectively and safely, the record can be improved and the quality of life preserved. 0 a D ED] AN IVI %N AA N U Rigs mounted onfixed platforms, usedfor de- velopment drilling after an oil or gas discov- ery, permit drilling thirty or more wellsfrom a single platform and location. After drilling, the rigs are removed, and the platform is used forproduction. --m" DATE DUE _@ I . I GAYLORD No. 2333 1 PRINTED IN U,S.A 11011111111110111119111111110 1 3 6668 14107 2258