Estimated ultimately recoverable

A final term used to define total oil reserves is estimated ultimately recoverable (EUR) reserves, which includes cumulative production to date, current reserve estimates, and those reserves that remain to be found and exploited. In Figure 2.11, the EUR would make up a portion of the resource base plus cumulative production to date. 

Estimated ultimately recoverable (EUR)—technical term describing the total amount of crude oil that will ultimately be recovered. This number is difficult to calculate and fluctuates frequently. Oil reserves are typically underestimated and are adjusted as additional information and new technology become available. Most experts believe that 1.2 trillion barrels (without oil sands) and 3.74 trillion barrels (with oil sands) reflect the world s total endowment of oil. 

A number of trends are anticipated in oil production in the next 20 years, including the Big Rollover (when oil production peaks, and begins to decline). Many oil experts believe this will occur within the next 10 to 15 years. Most experts agree that the earth s estimated ultimately recoverable oil reserves are about 1.2 trillion (short-scale) barrels without oil sands and 3.74 trillion barrels with oil sands. Present global consumption is 84.6 million barrels a day or 30.7 billion barrels per year. The United States produces 4.9 billion barrels per year and refines more than 8.5 billion barrels per year, while importing more than 16 billion barrels per year for commercial needs. These reserves cannot be replaced once they are used, and some projections indicate that, at our present rate of consumption, our oil reserves will be depleted during the next 38.8 years to 122.2 years. At the end of 2008, the world had consumed 1.12 trillion barrels. 

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. 

Resource estimates and current production According to the USGS, total resources of extra-heavy oil in place worldwide are estimated at around 1350 Gb, of which about 90% are located in the Orinoco Belt in Venezuela. It is estimated that between 240 and 270 Gb of the Venezuelan resources in place are ultimately recoverable. The synthetic crude produced from heavy oil is considered to be refined oil and is, therefore, not subject to OPEC quotas, unlike Venezuela s conventional oil production. 

Different estimates of the ultimately recoverable resources lead to different time windows for the mid-depletion point of oil. Estimates of the EUR at country level can differ, for instance, because of different boundaries between conventional and unconventional occurrences, and depend on assumptions about recovery factors,... 

The projected growth scenarios for conventional gas seem justified from the point of view of ultimately recoverable resources, and unlike for oil, no major discrepancies between projected demand and supply are to be expected in the coming decades. An important aspect of the future availability of natural gas, however, is the creation of the necessary infrastructure for the production and subsequent transport of the gas to the customer. The cumulative investments for the gas-supply infrastructure until 2030 are estimated to amount to US 3.9 trillion (IEA, 2006). 

Some estimates indicate that about 65.8% of ultimately recoverable natural gas in the United Slates will be found in structural traps the remaining 34,2% in stratigraphic traps. 

Whatever the ultimate recoverable reserves may be, current estimates of proven reserves of natural gas comprise about 50 percent of U.S. proven reserves of total petroleum energy. 

FIGURE F-2 Annual production scenarios for the mean resource estimate showing sharp and rounded peaks, 1900-2125. Growth rate leading to either peak is 2 percent. Sharp peak occurs in 2037 followed by decline at reserve to production ratio of 10. Rounded peak occurs in 2030 followed by decline at 5 percent. U.S. volumes were added to the USGS (2000) foreign volumes estimate to obtain a world total of 3,000 billion barrels (mean value) of ultimately recoverable resources. SOURCE EIA (2000). 

Estimated ultimate recovery ( UK) is not a resource category as such, but a term which may be applied to an individual accumulation of any status or maturity (discovered or undiscovered). Estimated ultimate recovery is defined as those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from an accumulation, plus those quantities already produced from there. 

As annual NaNOs shipments topped 1 million tonnes concerns arose about the long-term availabiHty of the resource. But, as is common with ultimately recoverable resource estimates, a widely publicized 1903 forecast—which concluded that at the rate the Chilean nitrates had been mined between 1840 and 1903 their deposits would be exhausted by the year 1938—was too conservative. In 1908 Alejandro Bertrand put the nitrate resources of the Tarapaca and Antofagasta regions at about 220 Mt, and a later detailed appraisal put the country s total probable resources at 920 Mt. If completely exploited, this resource would have been enough to support an annual output of 2.7 Mt, the rate reached just before the beginning of World War I, for 340 years—but those 920 Mt of NaNOj contain less nitrogen than is now fixed in just two years by the synthesis of ammonia ... 

The definitions above are an abbreviated version of those used in a veiy complex and financially significant exercise with the ultimate goal of estimating resei ves and generating production forecasts in the petroleum industry. Deterministic estimates are derived largely from pore volume calculations to determine volumes of either oil nr gas in-place (OIP, GIP). This volume when multiplied by a recovery factor gives a recoverable quantity of oil or natural gas liquids—commonly oil in standard barrels or natural gas in standard cubic feet at surface conditions. Many prefer to use barrels of oil equivalency (BOE) or total hydrocarbons tor the sum of natural gas, natural gas liquids (NGL), and oil. For comparison purposes 6,000 cubic feet of gas is considered to be equivalent to one standard barrel on a British thermal unit (Btu) basis (42 U.S. gallons). 

In April 1969 the Canadian Petroleum Association estimated the ultimate potential raw recoverable natural gas reserves of Canada to be 720.9 Tcf (at 14.73 psia and 60°F). If the total raw recoverable gas discovered through 1970 is subtracted from this value, a remaining undiscovered potential of 634.8 Tcf of raw gas is derived. Much of this undiscovered potential is attributed to Canada s frontier areas comprised of Northern Canada, Arctic Islands, Mackenzie Delta, Hudson Bay, and the continental shelf areas off the Atlantic, Paciflc, and Arctic Coasts. 

The fraction of oil-in-place recoverable from conventional petroleum reservoirs varies greatly with the reservoir type, oil viscosity, formation pressure, production rate, and finesse employed. The positive displacement aspect of water drive reservoirs generally gives them the highest ultimate petroleum recoveries, up to 70% of the oil-in-place [14]. Estimates of ultimate recoveries possible from gas cap drive and dissolved gas drive types of reservoirs are usually much lower, 25-50% for the former and 10-30% for the latter. Recovery from gravity drainage reservoirs will be at the lower end of the ranges of the two gas drive reservoir types. 

Estimates suggest there could be as many as 1.7 trillion barrels of oil trapped in the ground in Alberta (Woynillowicz et al. 2005), more than the total oil reserve estimates discussed earlier. However, current estimates suggest that out of this, only 315 billion barrels ultimately may be recoverable, and only 174 billion barrels can be classified as "reserves" based on existing technology and economics. Nevertheless, this is a very large reserve. Including the oil sand reserves, Canada is second only to Saudi Arabia in reserves. ... 

An important aspect of lead is that it is a recoverable resource. It has been estimated that more than 95% of the batteries sold in the United States are ultimately recycled, and it takes considerably less energy to recycle lead, a low-melting metal (mp 327.4°C), than to produce the metals used in other storage battery systems (nickel, iron, zinc, silver, and cadmium) in battery-grade quality. 

---