[MUSIC] So once the oil's been taken out of the ground, what happens to it next? Well, there are two things that have to happen. First of all, the oil has to be transported to where it can be used. And second of all, it has to be refined or turned into products that are usable for different purposes. So how does oil get carried from the oil field to the refinery? Two principle ways. First of all, there are pipelines. Now, you're familiar with pipelines perhaps in households. You're familiar with pipelines in cities. Oil pipelines tend to be a bit bigger. Diameter is maybe like that, to maybe like that they can be quite large, and also they have to in some cases go great distances. So you may see pipelines that are tens, hundreds or in some cases even thousands of kilometers long. Now, to put these pipelines in, is an extremely expensive proposition, and sometimes requires digging a huge ditch. Sometimes requires obtaining permission for land use rights for a large area. In any case, pipelines are usually installed either underground or in some cases on the surface. Here we see an example of a pipeline being installed underground. Notice that a large swath of land has to be cleared in order for it to be put in, and that that land can be reclaimed afterwards. Usually the pipeline companies will avoid allowing trees to grow over the pipeline, so that they have access to it in case there's a break or rupture later on. I mentioned that some pipelines are above ground. Perhaps the best known example of such pipeline is the TransAlaska pipeline. Which runs from the North slope of Alaska, the Arctic Ocean shore to the South shore of Alaska. A distance of about 800 kilometers or more. Now this pipeline has to be above ground, because most of the terrain it crosses is permafrost, permanently frozen ground. And in order for the oil to be able to flow it has to be warm, otherwise it would be too viscous. So if you just had the pipeline underground in a typical ditch, it would melt its way into the sub-surface and would probably get broken. So the Trans-Alaska Pipeline was a special engineering task that led to the production of a pipeline, that not only is above ground to avoid melting permafrost, but also crosses several active fault zones. And had to be able to accommodate the displacements associated with significant earthquakes. The pipeline networks in various parts of the industrialized world are really quite extensive. Heres a map of the United States that shows thousands upon thousands of kilometers of pipelines crisscrossing the country. Needless to say, many of them emanate from the oil rich portions of the country, such as Texas. Here's also a map of pipelines across Europe and a map of some of the pipelines in Western Asia. Now, pipelines of course are not the only way to get oil to market. In particularly, in the case of middle Eastern oil which is very far from where it's consumed in some cases. It's been necessary to build tankers. Ships that carry oil across the sea. Some of these tankers are absolutely immense, and have come to be known as super tankers. One of the largest, it can carry about 3 million barrels of oil, where a barrel is about 42 gallons. That makes this ship weigh on the order of 440,000 tons, ten times the size of the legendary Titanic. Once the oil has been brought into shore, it will be piped into large storage tanks, and from there taken to a refinery. A refinery is simply a place where the hydrocarbon molecules that are in crude oil, meaning the oil that's taken directly from the ground are cracked to form hydrocarbons of the right molecular length to serve specific purposes. Typically, the refining process takes place in a distillation column. In such a column, the crude oil is heated and it begins to undergo cracking reactions, breaking the larger molecules into smaller ones. The larger molecules stay near the bottom of its distillation column, and the lighter ones gradually migrate towards the top, because they have lower density. There are various spigots, so to speak, coming out of the sides of the distillation column, that allow the refiners to select whatever product that they want at any given time. So you can produce heavy oils at the bottom, some of which are used for the plastics and light natural gas, up at the top with gasoline, kerosene, and other substances in between. [MUSIC]
