The category includes establishments primarily engaged in drilling wells for oil and gas field operations for others on a contract or fee basis. This industry includes contractors that specialize in spudding in, drilling in, redrilling, and directional drilling.
213111 (Drilling Oil and Gas Wells)
Oil and natural gas drilling is expected to be a growing industry during the 2000s. In the late 1990s, worldwide production increases led to a glut of oil and natural gas on the market, which resulted in price declines. Consequently, many wells were idled. In the early 2000s, with demand once again pushing supply, drilling companies were undertaking new drilling opportunities as well as refurbishing idled drills to get them running again.
Drilling is an inherently volatile business that follows trends in the overall worldwide oil and natural gas markets. For example, rising oil and gas prices in 2001 led to nearly 1,300 active wells, the highest count since 1986. Within the following nine months, well activity plummeted 43 percent, to 743 active wells in April 2002. By mid-2003, active well totals approached 850. Because 80 percent of all U.S. drilling is related to natural gas, natural gas prices will likely dictate drilling activity, which is primarily inland based.
In the mid-1980s when Saudi Arabian crude oil flooded the market, the price of crude oil fell to $10 a barrel. American crude oil producers were hurt, but the rest of the domestic industry remained profitable, primarily due to strong consumption rates for refined petroleum products and chemical sales. The operators and producers of crude oil who survived the 1980s confronted an industry-wide collapse in 1991 and 1992.
The fall of natural gas prices sent the rig count plummeting to the lowest number in 50 years; drillers were most affected. Intense gasoline price competition led to the collapse of refining and marketing margins. An economic slump in the United States and a surplus of gas also contributed to weak prices.
Industry analysts continued to offer conflicting views regarding the future of the oil and gas industry through the mid-1990s—eventual recovery, little or no recovery, growth in the natural gas sector only. For the drilling sector of the industry, economic recovery was contingent on many factors, all related to the supply and demand for oil and its related products. Various indicators included economic growth in the United States, consumption rates, oil and gas prices, Organization of Petroleum Exporting Countries (OPEC) production and export rates, and the development of new markets for exploration.
Earlier in the 1990s, Standard & Poor's (S&P) anticipated U.S. oil consumption to approximate one-half of real growth in Gross Domestic Product (GDP). With long-term real GDP growth forecast at 2.5 percent annually, S&P predicted oil consumption to increase approximately 1.0 percent annually during the 1990s. Oil consumption did, in fact, rise from 17.979 million barrels a day in 1992 to 19.653 million barrels a day in 1999.
Gasoline consumption remained the largest component of total domestic petroleum use, with home heating oil in second place. Market analysts asserted that as Americans purchased more sports vehicles, which consume more gasoline than conventional automobiles, U.S. consumption of gasoline would increase. Increased consumption was also attributable to industrial and utility users who had dual burning capacity and switched from heavy fuel to natural gas. Natural gas consumption increased 4 percent over 1992 to capture approximately 25 percent of the U.S. energy market in 1993.
Natural gas can be found by itself or in association with crude oil. Natural gas is one of the cleanest burning fuels, producing primarily carbon dioxide, water vapor, and small amounts of nitrogen oxides. Prices of natural gas averaged $1.86 per thousand cubic feet in 1992, up 13 percent from the 1991 average of $1.59. According to the Independent Petroleum Association of America (IPAA), 1991 prices were abnormally low due to the warmer weather and the early release of gas from storage. By 1997, however, prices had risen to $2.42. Preference for natural gas continued to grow throughout the 1990s. The IPAA projected an annual growth rate of 1.7 percent through 2010.
By late 1995 the natural gas industry faced numerous challenges attributable to increased demand for natural gas, limited sources of new gas supplies domestically and in Canada, and record low levels of gas storage. The industry also faced low average natural gas prices in 1995, which discouraged exploration drilling activity. As a result, producers cut capital expenditures; productive capacity, subsequently, was reduced during the 1995-96 heating season. Although market analysts projected continued low capacity through 1997 and projected natural gas prices in major regional hubs to nearly double from 1995 prices, prices only rose to $2.42 per thousand cubic feet.
From 1989 through 1991, oil consumption fell. According to the Oil & Gas Journal , this continued decline was a result of a depressed level of drilling activity, the natural production decline rate of mature reservoirs, and a lack of access to prospective onshore and offshore areas. According to IPAA, crude oil production averaged 7.2 million barrels per day in 1992, which was the lowest level in 30 years. The trend continued and fell to 6.3 million barrels per day by 1998.
Oil prices averaged $12.12 per barrel in 1998, rose to $17.21 in 1999, and the U.S. Department of Energy (DOE) projected that they would continue to rise to an average of $21.86 per barrel in 2000. Natural gas prices also rose from $2.38 per million BTU (British thermal unit) in 1998, to $2.64 in 1999, and were expected to rise to an average of $2.89 in 2000.
Perhaps reflecting the price increase in crude oil, the U.S. rig count rose to 763 in November 1999, compared to 696 in 1998. The Canadian rig count was 336 in 1999, almost double the 183 operating in 1998. Only international drilling activity showed a decrease from 724 rigs in September 1998, compared to 557 in September 1999.
Saudi Arabia has been the dominant member of OPEC and maintained the highest share of OPEC oil export revenues. Other top OPEC oil exporters included Iran, Venezuela, Iraq, and Nigeria.
In the first half of the 1990s, U.S. exploration was centered in the Gulf of Mexico. As consumption of natural gas increased at the end of the twentieth century, companies continued to search for new sources of crude oil. Opportunities for international petroleum companies to explore, develop, and produce crude oil and natural gas in many areas of the world increased rapidly, particularly in the Asia-Pacific region.
Contract Drilling Firms. Contract drilling firms work with the well operators. Operators are the companies that decide what kind of well to drill and determine its specifications. Operators hold the lease rights and operate the lease as well. According to the Fundamentals of Petroleum, almost 98 percent of all gas and oil wells in the United States have been drilled by contract drilling firms. The drilling contractor usually is assisted by other companies, or subcontractors, that furnish specialized well services, such as casing and cementing (see SIC 1389: Oil and Gas Field Services, Not Elsewhere Classified) .
To remain financially viable, drilling contractors began to diversify their businesses to include other oilrelated services. Rowan Companies Inc., for example, diversified into an international aviation organization operating helicopters and fixed-wing aircraft. Between 1983 and 1995, while the drilling industry was in a state of turmoil and a period in which Rowan lost $342 million, its aviation division contributed more than $178 million in earnings. To diversify, Rowan Companies also operated another division, LeTourneau, Inc., a mini-steel mill and manufacturing facility that produces heavy equipment for the mining, timber and transportation industries, an international aviation service business operating helicopters and fixed-wing aircraft, and a marine division that has built more than one-third of all mobile offshore jackup drilling rigs.
Drilling contractors are primarily responsible for drilling wells, redrilling, reworking wells, and spudding (or startup) services. During 1995 Rowan Companies conducted offshore drilling operations in the Gulf of Mexico, the North Sea, offshore eastern Canada, and offshore Trinidad. The overall activity rate of its 21 offshore rigs in 1995 was 90 percent, up from 85 percent in 1994. Its drilling operations yielded an operating profit of $2.3 million, down $2.7 million from 1995.
Varco International, Inc., a manufacturer of products used in the oil and gas well drilling industry worldwide, reported that sales for 1999 totaled $80 million, down from $96.1 million in 1998. The reduced level of incoming orders in 1999 as compared to 1998 reflected the continued low level of worldwide drilling activity and the absence of new rig construction.
Drilling contracts specify a drilling contractor's obligations to the operating company. The drilling contract is important to both the drilling contractor and the operating company because it details responsibilities and expectations, such as the depth of the well, start date, and sizes of the hole and casing. Operating companies rely primarily on two kinds of drilling contracts: turnkey and footage, or daywork. Using a turnkey contract, the operating company is required to pay a set fee to the drilling contractor upon completion of the well. The contractor furnishes all the materials and labor, controlling the entire drilling process independently. Under a footage contract, a rate per-foot-drilled is established. This contract usually includes a daywork payment to compensate the drilling contractor for days when drilling has been suspended. This payment covers situations when the drilling rig is on site but has to perform nondrilling duties that are vital to well completion.
Drilling Rigs. All drilling rigs are designed to extract a significant amount of petroleum, which is trapped underground in a porous or permeable rock formation. The most common form of drilling rig has been the rotary rig. With rotary drilling, the rock formation is penetrated by a rotating bit connected to a hollow drill pipe. Fluid is pumped through the pipe, so that the rock cuttings can be brought to the surface. Two or more diesel or gas engines provide the required 1,000 to 3,000 horsepower, depending upon well depth and rig design. Rotary rigs are usually portable, so the contractor can be relatively mobile.
The operating equipment of a rotary rig can be divided into three systems: hoisting, rotating, and circulation. Wells are drilled using tremendous amounts of pipe and drill collars, sometimes weighing as much as 500,000 pounds. In order to move these items, the rig must have a hoisting system. The rotating system provides the power to the bit by turning it in the well bore. The rotary method spins the bit further and further into the ground, while the drill is lubricated to keep it cool and to flush out excess matter. The drill collar is heavier than the drill pipe and is used on the bottom of the string to put weight on the bit. The bit chews up the rock formation and dislodges it. The hardness of the formations determines the type of bit to be used. The circulating system is used to remove rock cutting and to cool the bit. Drilling fluid, often called mud, is a mixture of clays, chemicals, and water or oil, and is circulated in the drill hole.
Preparing a drill site requires many steps. The contractor must first clear and level the land, build access roads, make water available, and dig a pit to serve as a waste protector. At the site of the borehole, the contractor moves in the rig and other necessary equipment. Once the rig is in position over the conductor hole, the drilling begins to create the surface hole. The first drilling is accomplished by using a large bit attached to a drill collar, which is lowered into the conductor hole, with sections of the drill pipe added until the bit is on the bottom. Additional joints of drill pipe are added to the drill stem every 30-40 feet. At some depth, when the hole has been created beyond the gravel beds and other near-surface materials, the drilling subsides, and the drill stem is lifted out of the hole.
Pulling out the entire drill stem and bit is known as tripping out. Once the pipe is out, a casing crew moves in and runs the surface casing. Casing is a steel or iron pipe lowered into the well to prevent the walls from caving in during drilling and to keep gas and water from entering the well. Casing services are usually provided by an oil and gas field services subcontractor. Once in place, the casing is cemented by a subcontractor.
To resume drilling, or to trip into a hole, the drill stem with a new, smaller bit has to fit inside the casing. The bit, along with the drill collar, and each stand of pipe, is attached to the drill stem and is lowered into the hole. The drill bit continues to drill through the cement inside the casing. At some point, the drilling stops again, and another string of casing is set into the hole.
After the hole has been drilled to its determined depth, the operating company completes all evaluations regarding the economic viability of the hole. The company decides whether to set the production casing or plug the well. If it is determined that the well cannot produce enough oil or gas to compensate the costly completion services, then the well is considered to be "dry," and it is plugged and abandoned. If the production casing is to be set, it will be set by a contract casing crew. The drilling contractor's job is completed when the hole has reached final depth, and the casing has been set and cemented.
The petroleum pioneers based their drilling methods on the process of drilling for water: digging by hand. In 1857 operator Edward L. Drake and driller Billy Smith in Titusville, Pennsylvania, decided to try drilling for oil by hammering a pipe into the ground. The citizens of Titusville thought the project was foolishness and called the contraption "Drake's Folly." Even the financial backers of the venture gave up on the scheme and wanted Drake to abandon the project. But the driller, Billy Smith, did not give up, and soon enough the drill pipe struck oil. By the start of the 1860s, Titusville was covered with derricks, and the first oil boom had begun.
Early drilling methods relied on the cable-tool method, which was a rope or chain that suspended drilling tools into the well bore. Various methods were used to actually pound the drill bit into the ground. The tool's strings were relatively light, and the bit "looked something like a funnel." The process allowed the drill to penetrate one to two feet before the bit became dull. The drilling tools had to be removed from the well, the bit sharpened, and attached to a larger reaming instrument. If necessary the hole was pumped out, and the entire process began again. Versions of cable-tool drilling have been modernized and used in shallow wells. The cable-tool drilling system does not use injecting fluid or mud. Thus, the hole still has to be bailed out in order to remove cuttings produced during the drilling process.
Unlike the impact action of the cable system, in rotary drilling, the power of the bit comes from a rotating motion that turns the bit in the well bore. The circulation of fluid was an innovation by the Baker brothers in the 1880s. Fluid circulation allows particles of soft rock to float up the shaft and out of the way of the drill bit. The Bakers used their rig for drilling water wells in the Great Plains. The technique was also successful in the soft soil of Texas, where the great Corsicana oil field was discovered.
The petroleum industry's offshore operations began in the 1930s. Drilling in the shallow bays of the Louisiana and Texas Gulf coasts was conducted on wooden platforms mounted on timber piles. Most of the early activities in water-covered areas were designed to recover oil from reservoirs already defined on shore.
The offshore industry grew with the development of submersible and semisubmersible rigs, drill ships, and barges. Each year, independents dramatically increased their presence offshore, in both traditional production areas and in frontier deepwater leases. In 1999 more than 400 independents were active in the Gulf of Mexico, with at least 60 independents participating in the development of deepwater leases.
As the rig counts in American waters have declined, offshore drilling in other parts of the world has steadily increased. According to Oil & Gas Journal, a report by Infield Systems Ltd. noted that more than 1,400 new oil and gas fields will be developed prior to 2010. According to the New York Times, rig operators pulled their equipment out of the Gulf and hauled it to areas with more oil, including Venezuela, West Africa, and the North Sea.
According to IPAA, there were 835 U.S. rigs in operation in 1992. IPAA attributed the decrease in the number of operating rigs to the expiration of Section 29 tax credits and warm weather patterns. Some analysts predicted that the industry would pick up by 1993, estimating an average of 1,200 wells. Yet, the rig count stood at an average of 827 during the first half of 1998.
Environmental Issues. Industry leaders, such as those present at the 1992 Offshore Technology Conference, complained that the rapid decline in rig count has been due to rising costs and also to excessive environmental regulations. As these and other drilling experts have commented, the petroleum industry has been increasingly subjected to environmental considerations, a trend that continued throughout the decade.
The industry was mainly concerned with U.S. national energy policies. The Clean Air Act promoted the development and use of natural gas, which burns cleaner than other fuels. Although this legislation seemed to boost the natural gas market, it also included more stringent emission standards for offshore drilling, which directly affected well completion costs for drilling contractors. As new environmental laws and regulations were introduced, drilling contractors had to spend capital to meet standards set by these laws.
To meet demand, crude oil and petroleum products were imported at the all-time high rate of 10.4 million barrels per day in 1998, while exports measured 0.9 million barrels per day. Between 1985 and 1998, the rate of net importation of crude oil and products more than doubled from 4.3 million barrels per day to 9.5 million barrels per day. The share of U.S. net imports that came from OPEC nations reached 72 percent in 1977, subsided to 42 percent in 1985, and climbed back to 51 percent in 1998. Total net imports as a share of petroleum consumption reached a record high of 51 percent in 1998. The five leading suppliers of petroleum to the United States in 1998 were Venezuela, Canada, Saudi Arabia, Mexico, and Nigeria.
The price paid by refiners for crude oil in 1998 averaged $12.57 per barrel. When adjusted for inflation, the price was $11.15, fully 35 percent below the previous year's price and 79 percent lower than 1981's record inflation-adjusted price of $53.39 per barrel.
Up from less than $15 in early June of 1999, a jump in September of world oil prices put crude back to above $21 a barrel, the highest since 1997. The jump came on top of hefty fuel duty increases. The signs of a strengthening recovery in Japan and Southeast Asia drove the upward twist in oil prices.
The United States produced 19.0 trillion cubic feet of natural gas in 1998, well below the record-high 21.7 trillion cubic feet in 1973. Gas well productivity peaked at 435 thousand cubic feet per well per day in 1971, then fell steeply through the mid-1980s before stabilizing. Productivity in 1998 was 146 thousand cubic feet per well per day.
Annual petroleum consumption rose in the United States until 1973, when the Arab OPEC embargo stalled the annual increases for two years. Consumption peaked in 1978 at 18.9 million barrels per day. Rising prices over the next few years lowered consumption, which fell to 15.2 million barrels per day in 1983. Consumption began to rebound the following year and was boosted by plummeting crude oil prices in 1986. By 1998 it had reached 18.7 million barrels per day, close to the all-time high.
The resurgent U.S. natural gas market and new opportunities for work abroad should provide growth in the industry. Operators are expected to use more turnkey operations, risk sharing, partnerships, and to seek outside sources for certain services rather than developing them in-house, explained Sam Albright, of Howard, Weil, Labouisse, Friedrich, Inc., at the International Association of Drilling Contractors' (IADC) annual meeting. In Drilling Contractor, Albright added that the oil industry is restructuring, and consolidation will continue for the next few years.
During the early 2000s, world oil production and prices were quite volatile. Tensions in the Middle East rose after the terrorist attacks on the New York World Trade Center on September 11, 2001. As the United States was preparing for war with Iraq in late 2002, workers at the national oil company in Venezuela, which provides 14 percent of U.S. petroleum imports, went on strike. Venezuela's production fell from an average 3 million barrels per day to just 400,000 barrels per day, driving prices up. Then, in 2003 the United States engaged Iraq in war, causing oil prices to spike to $40 per barrel early in the year, before falling into the range of the mid-$20s in March 2003.
Crude petroleum drilling is expected to provide a gradual increase in production through 2007, before levels begin to decline. Most new growth in the drilling for petroleum will occur offshore, most often coming from existing idled platforms that could come back on-line as the economy recovers. Many of these platforms will have received upgrades during recent periods of downtime. Technological advances will provide advances in automation, as well as increase the speed and depth of the drilling.
Most opportunities in the well drilling industry will come from the natural gas sector. However, during the early 2000s high levels of reserves and unusually warm winters kept natural gas prices down, which directly impacted the utilization of drilling rigs. As supply tightened during 2002 and prices edged up, the drilling industry was looking hopefully toward recovery. In a fall 2002 issue of The Oil & Gas Journal, Marshall Adkins and Jim Rollyson predicted: " U.S. natural gas supply is falling at a record pace. …As a result, natural gas prices are setting up for an extremely robust 2003 and beyond. Since about 80 percent of all U.S. drilling is now natural gas driven, natural gas prices will be the key variable to watch to predict future US drilling activity levels."
On July 13, 1999, Schlumberger Ltd. announced that it had agreed to merge the offshore drilling operation, Sedco Forex, with Transocean Offshore, to create the world's largest offshore drilling company. The merged company was named Transocean. Both companies said the spinoff was in response to the increasing costs and technological demands of offshore drilling, which is taking place in deeper waters than in previous years. Transocean reported revenues of $2.7 billion in 2002.
GlobalSantaFe Corporation, a leading offshore drilling contractor, has drilling operations around the world. Its operations include 57 offshore rigs and 31 land rigs. GlobalSantaFe was formed in 2001, after Santa Fe International purchased Global Marine. Kuwait Petroleum, owned by the government, has a 29 percent share in GlobalSantaFe. The company reported a net income of $278 million on revenues of $2 billion in 2002.
Halliburton is one of the largest oil field services providers. Its Energy Services Group, which accounts for about 55 percent of revenues, provides well drilling services. Halliburton reported sales of $12.5 billion in 2002. Schlumberger Limited is another giant in the oil field services industry. The company reported revenues of $13.5 billion in 2002.
In 2001 the U.S. Department of Labor, Bureau of Labor Statistics, reported that the oil and gas field services industry employed 204,010 people. Over 50 percent of jobs were related to construction and extraction. The mean annual salary for a drill operator was $36,790.
The Department of Energy (DOE) has forecast strong opportunities for the export of U.S. energy services and technology through 2010. The international market for oil and gas exploration, excluding former Eastern Bloc nations and China, has been predicted to increase to $1.3 trillion per year from 1991 through 2010, as reported in Oil & Gas Journal. The DOE has estimated that U.S. vendors can capture $955 billion or 74 percent of that market.
According to the International Trade Administration, Department of Commerce, the Middle East and North Africa are of vital strategic interest to the United States and are of economic importance as a major source of the world's energy supplies. Export figures from the region support that assessment—Persian Gulf countries (Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), as of February 1998, produced 26 percent of the world's oil and held 65 percent of the world's oil reserves. Saudi Arabia and Kuwait alone accounted for about 12 percent of total U.S. crude oil imports.
Canada was the world's fifth largest energy producer, after the United States, Russia, China, and Saudi Arabia. The United States is Canada's major trade market for energy products, accounting for 91 percent of all Canadian energy exports (including nearly all of Canada's oil, natural gas, and electricity exports). Despite low oil prices in 1998, Canada's overall energy outlook was good. The country possessed abundant quantities of gas, coal, uranium, and oil, and was a major net energy exporter.
Latin America is also a promising market, especially Venezuela and Columbia. Although both have political risks, a joint venture has already begun between Benton Oil & Gas Co. and Vinccler CA, producing 2,100 barrels a day in Venezuela. According to the Wall Street Journal, this has been the first Venezuelan oil field operated by a U.S. company since the industry was nationalized in the mid-1970s. Southeast Asia has also become a lead target for development by U.S. firms.
Although overseas work can prove to be lucrative, it is not without its problems, most of which are not related to the task of drilling. Instead, contractors will have to learn about customs, work habits, and social behaviors for each country. Also, each market is decisively different, so what is known about one market will not be easily transferred to the next. Moreover, some overseas markets have grown to expect contract drillers to provide integrated services, "where the driller's participation in the planning and the management of the drilling programs are the norm rather than the exception," reported Luigs in Oil & Gas Journal.
Advances in research and technology in the contract drilling industry will continue to be the most critical factor to keep companies competitive. Continual improvements in technology and procedures have resulted in lower drilling costs and improved safety. At an annual meeting of the International Association of Drilling Contractors, both Suzanne Cook, industry analyst and first vice president of Merrill Lynch and Co., and Matt Simmons, president of Simmons and Co., International, agreed that "savvy exploitation of technology is one of the keys to repositioning for the future." Technological issues boil down to how to drill a well more efficiently and cost effectively.
Other technological advancements already in use are rig computerization and automation for daily drilling operations, such as Microsoft's Project Manager software. As reported in Drilling Contractor, Global Marine has developed a Rig Efficiency Program and has used the Microsoft program to monitor and analyze the performance of all its operations on every company rig around the world. Simmons added that while technology has profoundly changed the drilling industry, few advances have threatened to replace the rig itself.
Horizontal drilling uses drill bits driven by motors actually in the bits, instead of aboveground motors, and can be directed with the help of computers and detailed mapping. Drillers use horizontal drilling in aging fields, where earlier attempts might have missed oil trapped in narrow, vertical rock formations. Texas has remained the dominant region for horizontal drilling, with 81 percent of all horizontal wells. Some companies have begun to use the technique to search for new discoveries in North Dakota, Wyoming, and Colorado, where rock layers are similar to the ones in Texas fields, according to The New York Times.
According to the 1997 Swift Energy Annual Report, while horizontal drilling was still a small segment of the total drilling activity in the United States, its percentage of the total drilling activity increased sharply during the 1990s. Between 1991 and 1996, the number of horizontal wells drilled rose by 28 percent, while the total number of drilled wells fell by 23 percent.
In the field of exploration and production, technology revolutionized the way oil was found and gas was produced. Mobile Oil developed a new software that mimicked the way the human brain's neural network processes information. Using supercomputers, this tool integrated signs of gas, oil, or water from well measurements into a "big picture," provided by high-definition seismic readings taken over hundreds of square miles. Predictions could then be made regarding a reservoir's hydrocarbon locations. With this detailed reservoir picture as a guide, zones could be tested using flexible drilling technologies.
Adkins, Marshall, and Jim Rollyson. " U.S. Drilling Business Poised for Strong 2003 Recovery." The Oil & Gas Journal, 23 September 2002, 60-63.
Anand, Pradeep. "Solutions for OFS Industry Doldrums." Offshore, March 2003, 116.
"Drillers Think They See Light at the End of the Tunnel at Last." The Oil Daily, 11 April 2002.
Furlow, William. "Poised to Recover." Offshore, March 2002, 8.
"Mobile Drilling Units: Submersible Rigs." World Oil, February 2002, 30.
Perin, Monica. "Energy Industry Not Immune to Volatility in the Stock Market." Houston Business Journal, 21 September 2001, 6.
——. "New Generation of Land Drill Rigs Gets Pumped Up." Houston Business Journal, 27 July 2001, 2.
"Plugged: Offshore Oil Drilling." The Economist (U.S.), 7 December 2002.
Schmidt, Victor. "Industry's Challenges." Offshore, April 2003, 25.
Stark, Fortney, and H. Ken Chew. "Why Global Industry is Shifting Focus Offshore, into Deepwater." Offshore, December 2001, 28-29.
U.S. Department of Energy, Energy Information Administration. Crude Oil and Natural Gas Drilling Activity, 2003. Available from http://www.eia.doe.gov .
" U.S. Drillers See Improving Market Conditions After Long Slump." The Oil Daily, 5 April 2002.
Wetuski, Jodi. "Analysts: 2003 Could Be Excellent Year for Driller Stocks." Oil and Gas Investor, May 2002, 30.
——. "Workforce, Rigs Need Attention, to Meet Future Demand." Oil and Gas Investor, March 2001, 14.