Is there a relationship between mental health and the motives of a serial killer?
ock layers that contain migrated oil and gas) through horizontal wells. Although there is still an on-going debate on the precise definition of unconventional oil, in this essay we use the definition made by the IEA World Energy Outlook (WEO) in its 2011 report: “[u]nconventional oil include[d] extra-heavy oil, natural bitumen (oil sands), kerogen oil, liquids and gases arising from chemical processing of natural gas (GTL), coal-to-liquids (CTL) and additives.(https://www.iea.org/publications/freepublications/publication/WEO2011_WEB.pdf) Unconventional oil and gas are harder and more expensive to exploit, however, due to the increasing demand of oil and the continuous shift from coal to natural gas in electricity production, companies and governments have invested heavily in developing unconventional drilling methods. The most typical unconventional drilling method is the implementation of horizontal wells. They are drilled vertically downwards until reaching the target source layer and curve into a horizontal direction which runs a long distance laterally to give the wellbores extended contact with the formation. The advantage of horizontal wells is the long and constant exposure to source rocks. For example, a vertical well piercing a 30m-thick layer would only have 30m of exposure to the oil and gas interval, whereas a horizontal well would have several hundreds of exposures. Figure. The cartoon shows the difference between conventional (right) and unconventional (left) drilling methods. The branches extended on the horizontal well are the representatives of hydraulic fracturing. https://www.croftsystems.net/oil-gas-blog/conventional-vs.-unconventional Hydraulic fracturing, commonly known as fracking, further extends the drainage pattern around horizontal wellbores by creating fracture patterns that facilitate flow. Fracking injects a high-pressure ‘fracking fluid’ (primarily water, sand and chemicals) into a wellbore to create cracks in the rock formations which release the oil and gas inside. (https://ec.europa.eu/jrc/en/publication/eur-scientific-and-technical-research-reports/overview-hydraulic-fracturing-and-other-formation-stimulation-technologies-shale-gas-0) This method is now widely used world-wild, ensuring the US and Canada to have constant gas supply for 100 years and has presented an opportunity to generate electricity at half the CO2 emissions of coal. (https://www.bbc.co.uk/news/uk-14432401)>GET ANSWER