Resources and Reserves

Table 14. World Reserves and Resources of Phosphate Rock ...

At the present rate of world phosphate rock consumption (150 x 10 t/yr), the total world reserve (Table 14) is sufficient for about 200 years, and the resource would be sufficient for nearly 900 years. At expected increased rates of consumption, the reserves and resources are adequate for at least 150 years and 700 years, respectively. At projected rates of consumption, the high grade reserves in Florida probably will be exhausted by the year 2000. Rock production from the Florida reserve presentiy constitutes about 80% of all United States production and about one-third of world production (106). This rate of depletion is causing increased interest in western United States reserves which represent nearly 80% of present U.S. total reserves. 

In addition to the indicated total world reserves of about 21 x 10 t having P2 s content of at least 30%, and the 9.1 x 10 ° t classified as resources, there are about 250 x 10 t of reserves and resources derived from guano which are not included in Table 14. 

An assessment of world potash resources (108) is shown in Table 15. Of the 67 x 10 t of total estimated reserves and resources in Canada, nearly 5 X 10 t is recoverable by conventional mining methods and the remainder by solution mining. As of 1974, Canada had about half of the known world reserves and about 90% of known world resources of potassium. 

Table 15. Assessment of World Potash Reserves and Resources, t x 10 of K2O...

Molybdenum. U.S. reserves and resources are about 3 and 13 x 10 t, respectively. World reserves and resources are about 6 and 23 x 10 t, respectively (108). The requirement for fertilizer is very small. 

World Reserves and Resources. A summary of demonstrated and inferred worldwide reserves of lithium is given in Table 2. The reserve base and the lithium equivalent represent resources in the ground. An overall lithium recoverabiUty of 65% for pegmatites and 33% for brines must be apphed to these values to estabUsh the amount of lithium that could eventually reach the marketplace (15). 

The calculation of resource life involves the important distinction between reserves and resources. The current reserve is the known deposits which can be extracted profitably at today s price using today s technology it bears little relationship to the true magnitude of the resource base in fact, the two are not even roughly proportional. 

See also Agriculture Energy Economics Energy Intensity Trends Reserves and Resources. 

The terms oil production and gas production refer to rates of extraction of liquid and gaseous hydrocarbon materials from natural underground deposits. Reserves and resources, on the other hand, refer to amounts of oil and gas that are present in the deposits, the difference between reserves and resources being whether or not the amounts can be economically recovered under current conditions. Supply refers to the amount of a product that becomes available for... 

Our concepts of petroleum reserves and resources and their measurements are changing to reflect the uncertainty associated with these terms. Petroleum reseiwes have been largely calculated deterministically (i.e. single point estimates with the assumption of certainty). In the past decade, reseiwe and resource calculations have incorporated uncertainty into their estimates using probabilistic methodologies. One of the questions now being addressed are such as how certain arc you that the rcsciwcs you estimate arc the actual reseiwes and what is the range of uncertainty associated with that estimate New techniques arc required to address the critical question of how much petroleum we have and under what conditions it can be developed. 

There are many definitions of reserves and resources, and we need some historical perspective to understand the current debates. 

Classification of gas reserves and resources recommended by the World Petroleum Congress in 1987... 

The assessment and quantification of the remaining reserves and resources of fossil fuels is a very complex and broad field, characterised by a lack of internationally harmonised definitions and standards, great data uncertainties and discrepancies and, consequently, the potential danger of data abuse for political purposes. Within the scope of this publication, only an overview of the range of the currently available estimates of fossil resources is provided and the focus is rather on the general discussion of potential sources of uncertainty, than on a detailed assessment of the different methodological and statistical approaches and discrepancies at country or even field level. 

The boundary between reserves, resources and other occurrences is current. For several reasons, reserve and resource quantities and related supply-cost curves are subject to continuous revision. Production inevitably depletes reserves and eventually exhausts deposits, while successful exploration and prospecting add new reserves and resources. Price increases and cost reductions expand reserves by moving resources... 

The following terms are often used in the context of quantifying reserves and resources of fossil fuels the Estimated Ultimate Recovery (EUR), also called Ultimate Recoverable Resources (URR), is the sum of past cumulative production, proved reserves at the time of estimation and the possibly recoverable fraction of undiscovered resources. The remaining potential, i.e., the sum of reserves and resources, is the total amount of an energy source that is still to be recovered. The mid-depletion point is the point of time when approximately 50% of the EUR (at field, country or world level) has been produced. 

Table 3.2 shows the remaining potential (the sum of reserves and resources) of conventional oil at the end of 2005, which amounts to around 1800 Gb, made up of 1200 Gb reserves and 600 Gb resources. In line with the definition in Section 3.3.1, these figures do not include unconventional oil, such as crude bitumen from oil sands production in Canada or extra heavy oil from Venezuela.11 Almost three-quarters of... 

Figure 3.20 shows the distribution of the EUR, i.e., cumulative production, reserves and resources of conventional natural gas for different world regions. 

Resource estimates and current production Natural gas from coal is present wherever coal is found and, as coal is found in great quantities throughout the world (see Section 3.5), natural gas from coal may represent a large energy source. As for all types of unconventional gas, the published reserve and resource figures show great variations and are often based on estimations from incomplete data. In addition, as... 

Table 3.9. Worldwide hard coal reserves and resources, 2005...

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