Oil and Gas Reserves

The Oil & Gas Journal (OGJ) estimates that at the beginning of 2004, worldwide reserves were 1.27 trillion barrels of oil and 6,100 trillion cubic feet of natural gas. These estimates are 53 billion barrels of oil and 575 trillion cubic feet of natural gas higher than the prior year, reflecting additional discoveries, improving technology and changing economics.

The countries with the largest amounts of remaining oil reserves are: Saudi Arabia, Canada, Iran, Iraq, Kuwait, United Arab Emirates, Venezuela, Russia, Libya, and Nigeria. The largest reserves of natural gas are found in: Russia, Iran, Qatar, Saudi Arabia, United Arab Emirates, United States, Algeria, Nigeria, Venezuela, and Iraq.

Discovered (or known) resources can be divided into proved reserves and prospective or unproved (probable and possible) resources. "Proved reserves" are the quantities of oil or gas from known reservoirs and expected to be recoverable with current technology and at current economic conditions. Prospective resources are those that may be recoverable in the future with advanced technologies or under different economic conditions. The application of these distinctions is becoming blurred. For example, in 2003, Canada restated its reserves including its enormous non-conventional oil or tar sands with its conventional oil reserves.

The global energy community is currently engaged in debate about the extent of the world’s remaining oil reserves and the rate of their depletion. Traditional orthodoxy is being challenged and the actual definitions of the resource itself and of the term “reserves” are under scrutiny.

Some experts argue that worldwide conventional oil production will peak within the next few years. This prediction is based on a methodology advanced by M. King Hubbert, which concludes that while the production of oil can increase for some period of time, it eventually reaches a maximum and then declines until the resource is totally depleted. In 1956, Hubbert used this methodology to predict correctly that US oil production would peak in the early 1970s.

However, others argue that, while conventional resources may be limited, the world has enormous resources of unconventional oil which are increasingly competitive with conventional crude. One outstanding example is the case of Canada’s oil sands. Canada’s resources of oil sands or crude bitumen lie almost exclusively within three regions in the province of Alberta known as Athabasca, Cold Lake and Peace River. The Alberta Energy and Utilities Board has estimated the ultimate volume of crude bitumen in place to be 2.5 trillion barrels, although the World Energy Council quotes a slightly lower figure. About 370 billion barrels of this volume are believed to be economically recoverable at current prices and with current technology. Of the economically recoverable reserves, about 15% can be recovered using surface mining where the bitumen deposits are dug from the earth, while the remaining 85% require the use of in situ production processes, in which a well is drilled and the bitumen is extracted, often using unconventional technologies.

Australia's Coal Industry

Natural gas use in Australia is relatively small, but it has been growing rapidly in recent years. As a result of expanding consumption in a period of declining production, Australia is facing growing dependence on petroleum imports. Australia has 8.3% of the world’s coal reserves; 42.6 billion tonnes (Bt) of anthracite and 39.5 Bt of lignite. The total of 82 Bt amounts to 236 years of reserves at current production.

Coal is Australia’s largest energy source, supplying 44% of primary energy consumption, followed by oil with 33.4%.

Production of coal in Australia tripled from 127 million tonnes (Mt) in 1981 to 386 Mt in 2006. Australia has substantial domestic consumption, largely for power generation but the market is dominated by exports. Out of 386 Mt produced in 2006, approximately 97 Mt were consumed in Australia and the remaining 79% were exported. Australia is by far the largest coal exporter with 30% of the world’s export trade and Australian producers making extensions to their coal mining capacities.

Biomass in China

The biomass energy resources in China include the residue from agriculture and forestry processing, covering solid residue, the concentrated organic waste water from the agriculture products processing, crop straw and stalk burned as fuel, fuelwood, human and animal excreta, and urban residential refuse.

Traditionally, biomass was a major energy source in China but with the huge escalation of fossil-fuel generating capacity in the last 15 years, it is now dwarfed. 80% of biomass energy is rural, the principal biomass resource being crop residue, which accounts for over 52% of total biomass energy, followed by dung with 20% and firewood with 10%. Currently, 61% of rural household energy in China comes from traditional use of biomass. This means that each year approximately four billion tons of crop residues and woodfuel are burnt using stoves.

Among the extensive agricultural residues in China, the straw and stalk output alone reaches about 604 million tons. Calculated with a collection rate of 85%, the available amount of straw and stalk is 513.4 million tons, equal to 205 million tons of carbon equivalent (tce). Much of the 513.4 million tons of straw and stalk are presently used for cooking and heating in rural households. Other uses include forage, industrial raw material for paper production, and organic fertiliser. Presently, most of it is used at low efficiency. For example, in domestic cooking stoves the conversion efficiency is only 10-20%. The remainder of the straw is either dumped or burned in the field.

City refuse accounts for 18%. Crop and forest residues are mainly used as fuels for cooking food and/or heating by means of direct burning.