TRYING TO DO BETTER One innovation from recent years is a process known as refracking It is similar to the more widely known practice of fracking or hydraulic fracturing This method of extracting hydrocarbons involves breaking up large underground rock formations to free as much of the hydrocarbon as possible Once an initial round of drilling has established early cracks in a formation fluid is pumped underground at an extremely high pressure to widen the fractures and hold them open This makes it easier to insert pump lines and draw out the oil that lies beyond Refracking is the same concept with one notable twist Rather than creating new wells it is used to maximize the production from existing ones When older and less-capable technologies were unable to extract all the oil from a well the first time oil companies are able to use refracking to salvage the well They make tweaks to ensure every possible bit of oil can be retrieved For example they use fracking fluids with different viscosities to find the type that works best for a Hydraulic Fracturing and Earthquakes There has been much speculation in the media about the seismic dangers of hydraulic fracturing However evidence shows the risk of earthquakes from the fracking process itself is low Many fracking treatments have been carried out in the last 60 years and yet only a few isolated seismic events have occurred on the surface However the United States Geological Survey has determined the disposal of wastewater used in the oil and gas extraction process actually does cause earthquakes Most of this wastewater is a brine-type fluid that rises from reservoirs during oil and gas production As it has little use it is then put back into the ground through injection wells This increases the pressure underground and can trigger earthquakes 8
Hydraulic Fracturing In the hydraulic fracturing process fluids pumped underground crack rock formations releasing oil and natural gas The technique has proven effective and profitable but it has also proven controversial It involves moving large amounts of fluid and equipment to the fracking site this transport can take a toll on the environment Environmentalists also say fracking is a distraction from the eventual shift to renewable sources of energy 9
Petroleum and Oil The terms petroleum and oil are frequently used synonymously but there are notable differences in their meaning Crude petroleum is the dark liquid that occurs in nature as a complex mixture of hydrocarbons It has a heavy thick consistency After being extracted it is refined into numerous products including gasoline propane butane asphalt and a variety of oils Therefore the term oil is technically a generalization to describe one class of products that can be made from crude It is also used to describe the material that is sold and shipped in barrels from exporter to importer as in the phrase a barrel of oil However this is simply crude petroleum in its raw form It has not yet been refined as an oil product particular reservoir They seal off existing oil pathways to promote a steadier smoother flow of the oil that is traveling through new channels Fracking and refracking have made vast quantities of previously inaccessible petroleum available Refracking can improve efficiency but it still has many risks and hazards The production rate of existing reservoirs can potentially be disrupted by the procedure An adjacent reservoir being used in another well could be ruptured making the oil in both sites more difficult to reach The process has also been known to affect drinking water because of the poisonous chemicals often used in the fracking fluid And there is an ongoing concern that by disturbing the underlying geology of an area fracking can increase the risk of earthquakes However the potential rewards are significant Schlumberger Limited one of the giants in oilfield services estimated in 2015 that approximately 10,000 horizontal wells drilled during the previous five years alone were prime candidates for refracking 5 In one case in North Dakota 80 wells 10
