3.4. 1. 1 reserve growth
The reserves of crude oil are the resource base of output, so the increase of reserves directly affects the increase of output. Section 3. 1.2 has already expounded the growth of crude oil reserves and the proven rate of resources in the United States. After acquiring new recoverable reserves, oil and gas producers will develop these reserves under appropriate policies and market conditions, so the growth of production lags behind the growth of new recoverable reserves [95 ~ 98].
From the perspective of 48 states in the United States (excluding deepwater areas), the peak of crude oil production appeared in 1970, which was later than the peak of newly-increased recoverable reserves of crude oil (195 1 year) 19 years (Figure 3.34). According to the stage division of reserves growth in Section 3.3.2, 1970 is the turning point of the stable growth and decline of newly-increased recoverable reserves. After 1970, the newly-increased recoverable reserves in 48 states of the United States (excluding deepwater areas) showed an obvious decreasing trend, and the output began to decrease at this time. 1971~ During 2004, the output of 48 states in the United States (excluding deep water areas) decreased at a rate of 1.87%.
The newly-increased recoverable reserves and production * * * both affect the change of reserve-production ratio. Before the 1970s, the output of the United States increased rapidly. From 1945 to 1970, the crude oil output of 48 states in the United States increased at a rate of 4%, while the growth rate of new recoverable reserves in the same period was 1.89%. After 1967, the annual crude oil output of the United States almost exceeded the new recoverable reserves in that year. The reserve-production ratios of the United States and 48 local states (excluding deepwater areas) are slightly lower than 1968 and 1967 respectively. 197 1 During 2004, the average reserve-production ratio in the United States was 10.5 due to the reserve contribution of Alaska and deepwater areas since the 1990s. Without considering the contributions of Alaska and deepwater areas, the reserve-production ratio of 48 states in the United States (excluding deepwater areas) remained stable at 8 from the mid-1970s to the mid-1990s, but the average reserve-production ratio of 1999 ~ 2004 rose to 9.6, because the production declined faster than the newly added recoverable reserves.
Figure 3.34 Newly-increased recoverable reserves and production of crude oil in 48 States of the United States (excluding deepwater areas)
Figure 3.35 US crude oil reserve-production ratio
On the one hand, with the gradual decrease of newly-added recoverable reserves in 48 States (excluding deep water areas) in the United States, the recoverable reserves of crude oil are limited; On the other hand, whether from the perspective of national energy security or the business strategy of oil and gas producers, the reserve-production ratio will be regulated to some extent. These two factors determine the overall downward trend of output.
3.4. 1.2 Market oil price
Before the 20th century, the crude oil production in the United States was very low. After entering the 20th century, the invention of the steam engine boosted the demand for crude oil, and the US crude oil output exceeded 654.38+000000 tons in 1902. After the First World War, the automobile industry in the United States developed rapidly, and the output of crude oil began to increase rapidly. By 1944, US crude oil production has reached 229 million tons. During the period of 19 18 ~ 1944, the crude oil output increased at an average annual rate of 15.3%, and the average oil price in the same period was 1.33 USD/barrel.
During the period of 1945 ~ 1973, the domestic oil price in the United States was higher than the international oil price, which directly stimulated the continuous growth of crude oil production. The national crude oil production in the United States reached its peak in 1970, reaching 480 million tons. However, after that, the output of 48 States in the United States (excluding deep water areas) began to decline. During the two "oil crises" in the 1970s, the US government strictly controlled the oil price, which was much lower than the international oil price at that time, which made the oil-producing countries lose interest in domestic crude oil development and the US crude oil production began to decline. Although the crude oil production in 48 States (excluding deep water areas) in the United States slowed down after the oil price control was liberalized in 198 1 985, the oil price plummeted in 1986, resulting in a decline in production (.
Figure 3.36 US crude oil production and oil price
It can be seen from Figure 3.36 that after 1980s, the fluctuation of oil price can only stimulate the change of crude oil production decline rate in a short time, but the overall decline trend of crude oil production is inevitable due to the gradual slowdown of reserve growth.
The daily output of a single well is mainly related to two factors, one is the development and geological conditions of the oilfield, and the other is the oil price. Long-term development of oil and gas fields will inevitably lead to a decline in daily output of single wells after experiencing a peak, but from an economic point of view, daily output of single wells is very sensitive to changes in oil prices. The rise in oil prices has lowered the development threshold, enabling some low-yield oil fields that cannot be economically exploited under low oil prices to be economically exploited. The addition of low-yield oil fields reduces the average daily output of a single well. Under the influence of these two factors, there is a certain degree of negative correlation between the daily output of a single well and the oil price.
In the 1920s and 1940s, the crude oil reserves in the United States were in a period of rapid growth, and a series of large oil fields were discovered. At the same time, the daily output of a single well has increased from 0.3 tons/day in 1900 to10.52 tons/day in 1944 (Figure 3.37). Since 1945, the domestic oil price in the United States has been higher than the international oil price, which has promoted the development of low-yield oil fields. During the period from 1945 to 1958, the daily output growth rate of single well slowed down obviously. From 1958 to 1972, although the nominal oil price in the United States is still higher than the international oil price, after adjusting inflation and exchange rate, the oil price in US dollars actually decreased in 2004. At this time, the low-yield oil well can't be exploited economically, and the daily output of a single well gradually increases, reaching the peak at 1972, with an average of 2.49 tons. 1973 after the first oil crisis, the United States regulated oil prices. Although the domestic oil price is far lower than the international oil price, compared with before the oil crisis, the oil price not only rose sharply, but also continued to rise. By 198 1, when the US government lifted the oil price control, the oil price reached 3 1.77 USD/barrel. During this period, the daily output of oil wells in the United States has been declining, from 2.47 tons in 1973 to 198 1.70 tons in 2000. 1986 oil prices plummeted, some low-yield wells were gradually abandoned, and the daily production decline rate of single wells slowed down. Since 200 1, the oil price has continued to rise, and the daily output of a single well has continued to decline.
Fig. 3.37 Daily output of single well in 48 states (excluding deep water area) and US oil price.
3.4. 1.3 Development workload
The United States can maintain a fairly high oil and gas production level for many years at a low reserve-production ratio. Besides resource conditions, huge development workload is also one of the important reasons.
In order to maintain the stable and high yield of crude oil, the United States has to complete a lot of drilling work every year, and the number of oil wells has also increased greatly. When the crude oil output reached 654.38 billion tons for the first time in 654.38+0923, there were 290,000 oil wells in 48 states of the United States (excluding deep water areas). 1940, when the crude oil output reached 200 million tons for the first time, there were 390,000 oil wells. 195 1 When the output is 300 million tons, there are 475,000 oil wells; When the output of 1966 reached 400 million tons, there were 583,000 oil wells (Figure 3.38).
Since 1945, the development activities in the United States have experienced two peaks: the first peak occurred in the mid-1950s, and the number of mobile rigs in the United States reached the first peak, with a total of 2,686 rigs. 1956, a total of 4 development wells were drilled1000, including 28,000 crude oil development wells. The second peak appeared in the 1980s. 198 1 year, there are 3,970 mobile drilling rigs and 74,000 development wells in the United States, including 4 crude oil development wells. From 65438 to 0986, the number of development wells in the United States decreased due to the collapse of oil prices. Although the number of development wells in the United States has increased slightly since 2000, it is far below the peak period. In 2004, the United States drilled 32,000 development wells, less than the number of crude oil development wells 1985 (Figure 3.39, Figure 3.40).
From the perspective of 48 States in the United States, from 65438 to 0945, the United States began to implement the policy of higher than the international oil price, and domestic development activities increased accordingly. The number of development wells in 48 states in the United States increased from 18000 in 1945 to 4 10000 in 1956, an increase of nearly 1.3 times (Figure 3.4 1). However, in the 1960s, the seven major international oil companies manipulated the pricing power of crude oil, and the international oil price was depressed. Oil companies can make more profits by importing crude oil, and their development activities in their own countries are gradually decreasing. By 197 1, the number of development wells in 48 states in the United States had dropped to 1.9 million. From 65438 to 0973, with the arrival of the "first oil crisis", the United States began to implement a low oil price policy to protect the domestic economy. However, with the skyrocketing international oil price, the domestic oil price in the United States has also gradually jumped, which has stimulated the domestic development activities in the United States and gradually increased the number of development wells. 198 1 year, the United States completely lifted the price control, and the number of development wells reached its peak that year. However, with the collapse of international oil prices in 1986, the number of development wells also dropped significantly. 1973 ~ 2004, the correlation coefficient between the number of development wells in the United States and the domestic oil price in the United States in 2004 reached 0.53, with a significant positive correlation (99% confidence). This shows that development activities are significantly affected by prices.
Figure 3.38 Crude Oil Production and Oil Wells in 48 States of the United States (excluding deepwater areas)
Figure 3.39 Number of Development Wells and Mobile Rigs in the United States
The proportion of low-yield wells in the United States is relatively large. Compared with 1978, the number of production wells in 48 states in 1979 increased by 13952, of which 1 1675. By 1983, there were 440,000 low-yield wells with a daily output of less than 10 barrel (about 1.36 tons) in the United States, and the annual output of these low-yield wells was about 65 million tons. By 2003, low-yield wells accounted for 77% of the total number of oil wells in the United States, with an average daily production of less than 0.3 tons. The total output of these wells accounts for 65,438+05% of the total output of the United States [99]. There are two main reasons for the formation of "multi-wells and low production" [90]: First, the proportion of high-yield enriched reserves is small. According to the statistics of RAND Corporation in 1976, 9 1.3% of crude oil reserves in the United States are concentrated in 18 oil-bearing states. In these States, the reserves of super-large and large oil fields with recoverable reserves exceeding 500 million barrels (about 68 million tons) only account for 43% of the total reserves. Secondly, due to the "predatory exploitation" in the early stage of the development of American oil industry, the output of oil wells declined rapidly, and a large number of low-yield wells appeared.
Figure 3.40 Composition of Development Wells in the United States
Figure 3.4 1 Development Wells and Oil Prices in 48 States of the United States
3.4. 1.4 Development of development theory and technical progress
In petroleum exploration and development engineering, drilling is an indispensable basic link, which has the characteristics of capital and technology-intensive engineering and involves many theoretical and technical problems. The theoretical basis of drilling engineering is fluid mechanics, string mechanics, rock mechanics, chemistry, measurement and control, etc. Technically, borehole trajectory control technology, borehole stability technology, efficient rock breaking and well washing technology, oil and gas reservoir protection technology and oil well design technology are key technologies.
In the part of 2.3.2.3, this paper reviews the development of drilling technology in the United States. It can be clearly seen that drilling technology since the 20th century can be divided into four development stages: concept stage (1901919) and development stage (1920 ~ 1948).
Fig. 3.42 The history of crude oil production in 48 states of the United States (excluding deepwater areas) and the theoretical and technological progress of the petroleum industry.
Concept period: At the beginning of 20th century, American drilling technology just started, and the crude oil output increased from less than 190 1 to 500 million tons in 19 19. From 1859 to 19 19, the cumulative crude oil production in the United States only accounts for 2% of the recoverable resources in 48 States (excluding deep water areas). Technical progress constantly promotes the growth of single well production. By 19 19, the daily output of a single well has gradually increased to 0.30 tons.
Development period: After the 1920s, internal combustion engine technology promoted the rapid development of automobile industry. In drilling technology, the drilling rig driven by internal combustion engine was derived, and the roller bit and cementing technology were further developed. By 1948, the crude oil output of the United States increased to 276 million tons, the daily output of a single well reached 1.72 tons, and the crude oil recovery rate increased to 15.20%.
Scientific drilling period: with the development of American economy after World War II, the demand for crude oil is increasing, which promotes the continuous improvement of development technology. During this period, drill string mechanics and well deviation control theory, jet drilling, parameter optimization and formation pressure detection have been developed. By 1969, the crude oil output of 48 states in the United States (excluding deep water areas) reached 450 million tons, the daily output of a single well was 2.27 tons, and the crude oil recovery rate reached 37.60%.
Automatic drilling period: the introduction of computer technology and the research and development of wireless measurement while drilling technology in the 1970s are new milestones in the development of drilling technology. Computer technology promotes the mathematical modeling and quantitative analysis of drilling and accelerates the development of scientific drilling. After 1970s, the difficulty of mining in 48 states in the United States increased, which was manifested by the decline of reservoir quality and the increase of drilling depth. With the decline of the daily output of a single well, the oil recovery ratio of 48 states in the United States (excluding deep water areas) increased from 39% in 1970 to 70.4% in 2004. These data show that the development of American oil industry depends more and more on development theory and technology. Only with the continuous progress of theory and technology can we fully develop resources that were difficult to exploit before.
3.4. 1.5 Policies and regulations
Similar to the influence of policies and regulations introduced in section 3.3. 1.4 on the increase of reserves, select typical policies and regulations from many federal petroleum policies and regulations in the United States and analyze their influence on crude oil production (Figure 3.43).
Figure 3.43 US crude oil production and petroleum regulations and policies
The policy of "deduction of hidden drilling development fees" implemented by the US government in 19 16 can enable oil and gas producers to recover their investment in risk exploration and development as soon as possible, delay the payment of income tax to the government, and improve their enthusiasm for oil and gas exploration and development activities. 1924 implemented the "percentage loss reserve" policy, which maintained a large number of exploration risk funds for the American oil industry. These two policies were the direct driving force for the rapid growth of crude oil production in the United States in the 1920s and 1930s. Before the Great Depression, the crude oil output of 48 states in the United States reached 6,543.8+billion tons for the first time in 1923. Since 1926, the crude oil output has remained above 6,543.8+billion tons.
Before 1930s, oil and gas resources were in a state of disorderly exploitation. In order to protect petroleum resources, the amendment of 1930 mining lease law requires mining operators to drill according to the specified well pattern density. In addition, in order to stop the chaos of crude oil production, control production and stabilize oil prices, Oklahoma and Texas, which produce more oil, passed the laws of producing oil in proportion to market demand in 1928 and 1932 respectively. According to these laws and regulations, the National Law Committee determines the total demand for crude oil in a certain period of time, and then distributes it to various oil fields, and then distributes the production quotas of each oil field to mining lessees or wells. When the market demand is strong, the maximum production license of each well is stipulated; When the market is weak, the output of each well is limited to a certain proportion of the maximum allowable amount. From the Great Depression of 1929 to the implementation of the market demand ratio method, the oil price in some states fell to 10 cent/barrel, and the daily output of a single well declined rapidly due to predatory exploitation (Figure 3.37); After the implementation of this method, the oil price tends to be stable and the recovery rate of production wells is effectively controlled. 1934, California, Arkansas, Colorado, Illinois, Kansas, Michigan, Oklahoma and Texas formed an oil-producing state alliance. In 1935, the Connery Hot Oil Act was passed and approved by the National Assembly. These legal provisions not only stabilize oil prices, but also protect oil fields.
1959, President Eisenhower signed the Oil Import Restriction Program (MOIP). Part of the reason for implementing this plan is that the domestic oil price in the United States is higher than the international oil price. In order to reduce America's dependence on foreign crude oil and protect its oil industry, the US government limits its crude oil imports to no more than 9% of domestic demand. This plan will continue to stimulate the increase of crude oil production in the United States before the termination of 1973. 1970, the crude oil output of 48 states in the United States (excluding deep water areas) reached its peak, reaching 468 million tons.
1973 "the first oil crisis" broke out. Affected by the oil embargo and high oil prices, the federal government terminated its plan to restrict oil imports and passed the emergency oil distribution law. The law stipulates that the limited domestic oil production should be distributed to refineries or other consumers, and at the same time, the maximum price of crude oil is stipulated. 1975, the emergency oil distribution law was terminated and the energy policy and energy conservation law were passed. Although the price restrictions on some petroleum products have been lifted, the law still controls the price of petroleum. During this period, domestic oil producers in the United States could not enjoy the benefits brought by the rise in oil prices in the international market, so most oil development activities turned to foreign countries. The crude oil output of 48 states in the United States dropped to less than 397 million tons at 1976, which was 15.20% lower than that at 1972.
During 1979, the political changes in Iran triggered the "second oil crisis", and the US government announced that it would gradually lift the domestic crude oil price control within 28 months from 1979 to stimulate domestic crude oil exploitation. But then, in order to prevent oil and gas producers from profiteering due to the deregulation of domestic oil prices and the rise of oil prices in the international market, Congress passed the crude oil surplus tax law, which came into effect in March 1980, and President Reagan cancelled the crude oil windfall tax in the mixed trade bill signed by 1988. During the windfall tax period, due to the deregulation of domestic oil prices in the United States, the rise of international oil prices stimulated domestic crude oil development activities in the United States, especially during the period of 198 1 ~ 1985, high oil prices lowered the threshold for crude oil exploitation. During the period of 198 1 ~ 1983, the crude oil output of 48 local states (excluding deep water areas) remained stable, while the crude oil output of 1984 and 1985 rebounded somewhat, approaching the level of 360 million tons.
Since the mid-1980s, domestic crude oil production in the United States has gradually declined. In order to reduce the dependence on foreign crude oil, the government began to pay attention to the exploration and development of unconventional oil and gas resources, and successively adopted some preferential measures to stimulate the growth of crude oil production. 1989 passed the unconventional oil and gas resources credit law, which stipulated that 10% of the expenditure capital of low-yield wells, heavy oil, marginal oil wells and tertiary oil recovery technology can be used for tax credit. 1995 passed the law of exempting deep-water mining royalties, and the implementation of this law greatly stimulated the oil and gas development activities in deep-water areas. 1994, the output of deepwater area reached 54 million tons, 1995 reached 65 million tons, and in 2000 reached1970,000 tons. The Law on Exemption of Royalty in Deep Water Mining Areas was terminated in 2000, but the US government continues to give preferential policies to oil and gas exploration in deep water areas, and the higher the risk, the higher the cost of exemption.
To sum up, among many factors that affect the growth of crude oil production in the United States, reserve growth is the resource base, and production is limited by proven reserves; The influence of market oil price on American crude oil production is limited to a certain period, which belongs to indirect control factors and is regulated by national policies in the early stage; Development workload is a direct factor affecting output; The development theory and technological progress reduce the cost and improve the success rate and efficiency of development, which is an important driving factor; Government policies and regulations are macro-control factors that affect output. On the one hand, the government stimulates development activities by adjusting oil prices through policies and regulations, on the other hand, it develops new development theories and technologies by implementing a series of preferential tax and fee measures to guide development investment. Development workload is the direct embodiment of development investment. Greater development workload brings higher output. The changing trend of output also affects the government's policy on the oil industry. Combined with the relationship between crude oil reserves growth and various influencing factors, the relationship between crude oil reserves and production growth and various influencing factors is shown in Figure 3.44.
Figure 3.44 Relationship between US crude oil reserves and production growth factors