Oil Facts

As it becomes covered with further sediment over the course of millions of years, this layer is exposed to high pressures and temperatures. By the end of the process, it might seem as if the biomass has been “sunk” into the base ground; this is a popular error, instead, the biogenetic sedimentary layers have been covered over by ever more sizeable strata over a long period of time. Under such conditions, the long-chain, water-insoluble hydrocarbons contained in the biomass (the so-called kerogens) are split into short-chain, gas-like, liquid hydrocarbon chains, a process that is also known in the industry as “cracking”. The finely distributed kerogens are disintegrated by pressure and temperature, but not oxidized, and are able to find their way into the pores of minerals; this process is known as migration. The hydrocarbons collect in so-called “reservoir rocks” as petroleum and natural gas. 

A so-called gas cap is often created above oil deposits under very similar conditions to petroleum. Drill core sample from a petroleum-bearing layer of sandstone. A range of geological factors must be present to ensure the conversion of kerogens into petroleum and natural gas; the pressures and temperatures that occur during catagenesis play an important role here. Current scientific opinion suggests that a sub-surface depth of about 4000m should not be exceeded for bedrock and reservoir rocks to ensure that the hydrocarbon chains contained in the petroleum remain stable; these regions are also known as petroleum windows. Only natural gas deposits are likely at greater depths. Optimal conditions for the formation of petroleum as far as pressure, temperature and suitable oil trap structures are concerned are generally located on passive continental shelves, in rift zones and in the vicinity of subterranean salt domes. Over the course of further diagenesis, the kerogens may become bituminous, i.e. viscous and immobile. Because of the high costs involved, such deposits are of no interest for recovery in the first instance, but higher oil prices may make the processing of heavy oil fractions worthwhile. Sedimentary rocks containing high proportions of biogenic hydrocarbons are known as petroleum source rocks. An example of hydrocarbon-rich sedimentary rock that is well-known in Germany is Black Jura oil shale, which is often found on the surface in South Germany and is also an important petroleum source rock in the North Sea area. Sandy, petroleum-rich sediments that are found near the surface are known as oil sands.

Optimal conditions for the formation of petroleum as far as pressure, temperature and suitable oil trap structures are concerned are generally located on passive continental shelves, in rift zones and in the vicinity of subterranean salt domes. Over the course of further diagenesis, the kerogens may become bituminous, i.e. viscous and immobile. Because of the high costs involved, such deposits are of no interest for recovery in the first instance, but higher oil prices may make the processing of heavy oil fractions worthwhile. Sedimentary rocks containing high proportions of biogenic hydrocarbons are known as petroleum source rocks. An example of hydrocarbon-rich sedimentary rock that is well-known in Germany is Black Jura oil shale, which is often found on the surface in South Germany and is also an important petroleum source rock in the North Sea area. Sandy, petroleum-rich sediments that are found near the surface are known as oil sands.

In the early period of petroleum production, people relied on features on the earth’s surface that might suggest the deposits of petroleum. Shallow deposits continually leak small amounts of petroleum and an example of this is the now exhausted St Quirin’s well near Bad Wiessee, on the lake at Tegernsee, which had been known since the 15th century; the petroleum that it exuded for centuries was primarily used as a medicine. Searches for deep oil deposits used to be carried out through a comprehensive analysis of the geological characteristics of an area of land. 

Test drillings were subsequently undertaken at selected locations, of which about 10 – 15% were successful. Sophisticated investigative methods were developed over time to make an increasingly detailed evaluation of the ground layers possible. The most common procedure is reflection seismology; here, vibrations are transmitted from the earth’s surface and the signals reflected by the varying ground strata are received with geophones and recorded.

Strata profiles can be calculated from the transmission times and characteristics of the reflected signals. The Vibroseis technique is used in about 2/3 of cases in Europe; here, groups of usually three to five special vehicles (which transmit a defined frequency to the ground by means of a kind of vibrating plate) are driven along a measured distance. Geophones are deployed in groups along the route to receive the reflected signals. Systematically covering an area with interlinking measuring routes makes it possible to calculate a three-dimensional model of the ground strata.

Given the current state of technology, prospected land and consumption, petroleum reserves are enough to cover global consumption for another 50 years. The term “petroleum constant” describes a circumstance whereby such predictions of the static scope of petroleum may be regularly updated in the same way as with other commodities. In 2003, the largest petroleum reserves were located in Saudi Arabia (262.7 billion barrels), Iran (130.7 billion barrels) and Iraq (115.0 billion barrels), followed by the United Arab Emirates, Kuwait and Venezuela. However, critics of these reserves estimates point out that most of the reserves in countries that are not members of the OECD are not subject to independent monitoring (see footnotes to BP statistical review) and in many cases (such as in Saudi Arabia), all details of recovery data relating to individual fields and reserves are state secrets; for this reason, such critics consider these figures to be incorrect. A number of OPEC oil-producing countries are also suspected of being too optimistic in their estimates as their production quotas are dependent on the reserve volumes they record.

Given daily consumption of 87 million barrels, reserves of 1255 billion barrels would predict a cutoff period of about 40 years, and for 854 billion barrels about 27 years. When evaluating this figure, it should however be remembered that a global petroleum shortage will not arise until this (static or dynamic) period is completely up; unlike a tank, our petroleum reserves are not able to dispense daily volumes (production rates) of oil at will. Instead, there is a maximum possible production rate which is often reached when the well is about half exhausted, after which the recovery rate drops away (for physical reasons). Many experts are also expecting similar behavior in global oil production: after reaching a global production maximum (“peak oil“, see above), the global recovery rate will drop away. 

According to Abdullah Jum’ah (CEO of Aramco), approximately 1.1 billion barrels of oil had been recovered in the history of mankind up to the beginning of 2008. Most of the reserves were discovered in the 1960s. Since the beginning of the 1980s, annual production (2005) has been 30.4 billion barrels (with 87 million barrels consumed per day in 2008) – an amount beyond the capacity of the newly discovered reserves, with the result that existing reserves have been decreasing since this time. For this reason, some experts calculate the global production limit will bve reached some time between 2010 and 2020. Kenneth Deffeyes, Colin J. Campbell and Jean Laherrere fear peak oil may already have been reached before 2010. One result of this production maximum would be an ensuing drop in production, such that the demand forecast to run parallel with economic growth would no longer be met. 

Increasingly critical analyses depicting the threat of shortage scenarios in the short term have been provided by the British government, the U.S. Department of Energy and the central analysis service of U.S. Joint Forces Command, the United State’s defense force. The British government clearly seems to be reacting to the fact that Britain’s oil wealth has been dropping by approximately 8% per annum since 1999; as a result, the UK went from being an oil exporter to an importer in 2006.  Abdullah S. Jum’ah rejects such fears; he estimates that less than 10% of existing liquid oil deposits (including non-conventional reserves) has been recovered and at current consumption rates, there is enough petroleum to last for at least another 100 years. 

However, preliminary results show that importation of petroleum and natural gas to Germany rose in value by more than a quarter (+28.4%) from 2005 to a total of 67.8 billion Euro in 2006 alone; the estimated peak in 2008 brought a total of 83 billion Euro with a further rise of +10% on the previous year’s tally. Figures from the Federal Office of Statistics for the period from 1995 to 2008 inclusive indicate that petroleum and natural gas imports increased from 14.44 billion to no less than 82.26 billion Euro, rising from an initial proportion of 4.3%, to represent 10% of all imports.