Shale-Oil

The production of shale oil requires the converting of organic matter (kerogen) that exists within certain rocks, into synthetic gas and oil. The synthetic oil produced in this manner can be used immediately as a fuel, or it can be processed further to allow it to become feedstock for existing oil refineries by first removing nitrogen and sulphur impurities. Once refined it can then be used in the same manner as the that derived from crude oil.

Shale oil is not a new discovery, in fact it was used by civilisations in Austria and Switzerland as far back as the 14th century. In fact, in 1596, it was also discovered as having certain healing qualities. With the advent of the 17th century, shale oil was used in Modena, Italy for street lighting purposes. In 1694 a British patent was granted for the production of oil, tar and pitch from stone. A more modern method of extracting shale oil was established in the 1830's and by the 1840's shale oil was widely used throughout Scotland for lamp oil, as a lubricant and as a fuel substituting the need for whale oil.

The first shale oil extraction plant to be established in Australia occurred in the latter half of the 19th century and continued production into the 20th century, however, the discovery of cheaper and more easily refined crude oil from the Middle East forced the closure of such plants throughout the world. The slowing down of world crude oil production saw an increase in price in more recent times and as a result there has been increasing interest shown in re-development of a shale oil industry.

In recent times, in Australia, seismic and drilling exploration has discovered up to 233 billion barrels of shale oil could be contained in reserves in the 30,000 square kilometre Arckaringa Basin in South Australia, near Coober Pedy. If this find is realised it will be 80 times larger than the U.S. Eagle Ford shale oil deposits, six times larger than the famous U.S. Bakken deposit and 17 times larger that the Marcellus formation. This South Australian shale oil find can be put into perspective when it is compared with the Saudi Arabian reserves estimated to be 263 million barrels. If this deposit is proven up, along with other shale oil discoveries along the eastern states of Australia, the country will secure its future energy requirements along with it becoming a major export commodity.

Reactive fluid processes, such as thermal dissolution and hydrogenation, extract oil from rocks by using certain solvents, or hydrogen donors, or a combination of both. The thermal dissolution process requires the application of solvents at high pressures and temperatures. This increases oil output by a process known as 'cracking' which is simply breaking down long-chain hydrocarbons into short hydro carbons. Cracking dissolves organic matter. However, rocks containing shale oil can have differing properties and this means different ways are needed to produce shale oil depending on the circumstances at the time.

Shale oil is not as fluid as crude oil, as where crude oil becomes pourable at temperature between minus 60 to 30 degrees centigrade shale oil doesn't become pourable until it reaches a temperature between 24 and 27 degrees centigrade. This difference in reaction to temperature conditions seriously effects the ability of shale oil to be transported through pipelines as is the practice of moving crude oil. Raw shale oil can also clog downstream processing because of it containing sulphur and nitrogen that creates air pollution. It can also contain arsenic as well as iron that has the potential to destroy certain refining processes. Oxygen levels in shale oil is higher than that of crude oil and this tends to form destructive free radicals.