Better Fill up today

[DanCookson]

March-09 Crude is trading at $34.79.

[DanCookson]

March-09 Crude is trading at $37.40.

[Warph]

How Oil Pipelines Work

 

Oil  pipelines are frequently in the news these days because they can have a big effect on oil prices. For example, if a war or terrorist activity threatens to shut down an important pipeline, oil prices can rise. Oil pipelines can also make the news when they leak.

One of the best-known pipelines in the United States is the Trans Alaska Pipeline System. It stretches north-to-south for 800 miles across the state of Alaska. The oil comes out of the ground at the North Slope near Prudhoe Bay, flows down the pipeline to the port of Valdez, loads onto a supertanker, floats down to the west coast, unloads into another pipeline and makes its way to a refinery. The Alaska pipeline is needed because Prudhoe Bay freezes in the winter, while the port of Valdez is ice-free year round.

At its simplest level, you can think of a pipeline as a pipe and a pump. The pump sucks up oil from a storage tank and sends it down to the other end of the pipe. If the pipe is only a few miles long, this simple system works fine. In the early days of oil drilling and distribution, pipelines this simple were common. But modern oil pipelines like the Alaska pipeline are far more sophisticated.

For example, the Alaska pipeline carries approximately 40 million gallons of oil per day, and can approach 100 million gallons per day if necessary. To handle this volume of oil, the pipeline is four feet in diameter. As the oil flows, friction against the pipe wall slows it down. Therefore, approximately every 100 miles, a pumping station boosts the pressure. The oil pressure inside the pipeline is over 1,000 PSI. To handle that kind of pressure, the pipeline is made of steel that is more than three inches thick.

That still sounds pretty simple - you have a big pipe and some pumping stations. But then you have to consider expansion. The steel in the pipeline can potentially get as cold as minus 60 degrees F. Or, with a maximum load of high-pressure oil flowing, it can get as hot as 145 degrees F. That's a 205 degree temperature swing. Keeping in mind that steel contracts when it is cold and expands when it gets hot, you can see the problem. An 800 mile long steel pipeline can grow or shrink by more than a mile depending on the temperature. To handle that much expansion, the pipeline has to be able to expand and contract at all of its joints without leaking.

What happens if something goes wrong and the pipeline springs a leak? With the oil at such a high pressure, you can get a geyser. For example, in 2001, the pipeline was shot by a drunk man wielding a hunting rifle. Although the hole was small, more than 2 gallons of oil per second shot out of the pipeline. Since it took more than a day to find the leak, almost 300,000 gallons of oil inundated nearby trees and tundra.

Fixing the leak presents its own problems. You have to shut down the flow of oil on the entire pipeline, find the leak, isolate that section of the pipeline, drain the oil and fix the problem. It can be a huge, messy project. The Alaska pipeline has experienced hundreds of leaks over its lifetime.

You might be wondering how a rifle bullet could penetrate steel that is three inches thick. The problem is corrosion, which thins the steel over time and makes the pipeline more prone to leaks. To check for corrosion, pipeline engineers use a robot called a "smart pig" to run down the inside of the pipeline and check for problems. The thickness of the steel can be detected with a magnetic field. Where the steel gets thin, the way it handles a magnetic field changes, and sensors can detect those changes. When the pipeline gets too thin, sections have to be replaced.

Given all this complexity, you might be surprised to learn that there are oil and gasoline pipelines crisscrossing the United States. These pipelines stretch for tens of thousands of miles. They work around the clock to connect ports, oil fields, refineries, and major distribution points. Because these pipelines are almost always buried, they tend to be invisible. But they are essential to our day-to-day life. Without them, the flow of oil and gasoline in the United States would come to a standstill. 

[Teresa]

That's interesting. Thanks to all who are adding to this thread.

[Warph]

....and here's another one....

How an oil refinery works

Every time you pump gas into your gas tank, you are benefiting from one of the most amazing chemical factories know to humans: the oil refinery. An oil refinery produces gasoline as well as many other substances - everything from dry cleaning fluid to petroleum jelly to road tar comes from an oil refinery. Let's go behind the scenes and see how an oil refinery works.

An oil refinery is made possible by the amazing nature of crude oil. When an oil company pumps crude oil out of the ground, it is pumping a mixture of many different substances. All those substances have one thing in common: They are all made of hydrocarbon chains of different lengths. The goal of an oil refinery is to sort out all the different chains by length.

A hydrocarbon chain is simply a molecule made of hydrogen and carbon. Carbon atoms link together to form the backbone of the chain, and then hydrogen atoms attach to the carbons. The simplest hydrocarbon chain has just one carbon atom along with four hydrogen atoms. This hydrocarbon chain is called methane. Methane gas is so light it floats, like helium. When you use natural gas, you are using methane. Ethane is next, with two carbons in the chain.

Once you get five carbon atoms in a chain, you have a liquid, and the liquids get thicker and thicker as the chains get longer. Gasoline, kerosene, diesel fuel and motor oil are all made from hydrocarbon chains. Gasoline has between seven and 11 carbons in the chain. Kerosene has between 12 and 15 carbons, and so on. Once you get beyond 20 atoms in a chain, you move from liquids to solids: things like petroleum jelly, paraffin wax and finally tar.

An oil refinery sorts out all these different substances using heat. If you heat crude oil up to 600 degrees centigrade, it boils and all the crude oil evaporates. This crude oil steam then flows into the bottom of a tall distillation column. The column is set up so that, at different heights inside the column, there are different temperature zones. As the crude oil steam rises in the column, it cools, and the different hydrocarbon chains condense out into liquids. There are trays at different levels that collect the different liquids and send them through pipes to storage tanks.

If you were to go back 100 years, an oil refinery was this simple. You had a tank that boiled crude oil and a distillation column to collect the different kinds of hydrocarbons. The big problem with this approach is that only 40 percent of a barrel of oil is naturally gasoline. The rest of the barrel naturally contains longer or shorter chains. Many oil refineries today want to make mostly gasoline, so there needs to be a way to change longer and shorter chains into gasoline, either by putting them together or splitting them apart.

Cracking is the process of breaking longer chains apart. Using heat and catalysts, long hydrocarbon chains break down into shorter, gasoline-length chains. So the refinery might take the paraffin wax from a barrel of crude oil and run it through a cracker. Then it can distill the output of the cracker and extract a lot more gasoline.

The other side of the coin is unification. Here, short hydrocarbon chains link together to form longer chains. A catalyst breaks hydrogen atoms off the end of the chain and links chains together.

Using these techniques, an oil refinery can turn almost everything in a barrel of oil into gasoline-length chains. The chains are blended together to get gasoline that performs perfectly in a car engine.

The final step at a refinery is to purify the gasoline. For example, there might be a step that removes sulfur from the fuel. Another step removes any water and nitrogen compounds.

What comes out of the refinery is gasoline ready to go into a pipeline or tanker truck so that it ends up at your local gas station. From there, you pump it into your tank.

[Dee Gee]

Thanks you, Warph. I like your simple explaination of a refinery.

[Warph]

How Octane Works

Every time you pull up to a gas pump to buy your gas, you are faced with a choice: Do you want 87, 89 or 93 octane gas? Which leads to the obvious question: What is octane, and why would you care? Why can't there be just one kind of gasoline? Let's take a look at what is really going on with octane.

It all starts with your car's engine. Any gasoline engine is inhaling air, mixing the air with gasoline, compressing the air/gas mixture and igniting it with a spark plug. The compression part is important when it comes to octane. The amount of compression is called the compression ratio of the engine. A typical engine might have a compression ratio of 8-to-1.

When an air/gasoline mixture gets compressed, there is some amount of compression that will cause the gasoline to spontaneously ignite. The gas doesn't need a flame or a spark  just the act of compressing it will cause the gas to ignite. This kind of spontaneous ignition in an engine is bad because it causes knocking, and knocking can damage an engine.

So when you fill your tank with gas, you need to know whether the gas will spontaneously ignite (and therefore knock) or not. The octane rating gives you a way to measure gasoline's resistance to spontaneous ignition. Eighty-seven octane gasoline is good enough to work in normal engines that have a normal compression ratio. But many "high performance" engines use higher compression ratios, and they need 91 or 93 octane gas.

How do you find out if your engine needs 87 octane or 93 octane gas? You look in the owner's manual and it will tell you. Before you buy a new car you should check this, just to make sure, since 93 octane gas is getting pretty expensive these days.

What happens if you put 87 octane gas in a "high performance" engine? If it is an older engine, it is likely that it will knock like crazy. With newer computer-controlled engines, the computer can sense the knocking and make some adjustments. It might change the ratio between air and fuel, or change the spark timing, to try to reduce the knocking. Your engine might not perform very well and it might not get the best mileage, but it probably won't be damaged by knocking.

What happens if you put 93 octane gas in a "normal" engine that needs 87 octane gas? Nothing. It is a waste of money, because 93 octane gas isn't needed in a "normal" engine.

You might be wondering what the number 87 actually means, and where the name "octane" comes from. The name comes from the following fact: When you take crude oil and process it in a refinery, you end up getting hydrocarbon chains of different lengths. These different chain lengths can then be separated from each other and blended to form different fuels.

Heptane has seven carbon atoms chained together, and octane has eight.

It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well. You can compress it a lot and nothing happens.

Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane). It spontaneously ignites at a given compression level, and can only be used in engines that do not exceed that compression ratio.

During WWI, it was discovered that you can add a chemical called tetraethyl lead (TEL) to gasoline and significantly improve its octane rating above the octane/heptane combination. Cheaper grades of gasoline could be made usable by adding TEL. This led to the widespread use of "ethyl" or "leaded" gasoline. But lead was eventually banned because it is toxic and because it clogs catalytic converters.

When lead was banned, gasoline got more expensive because refineries could not boost the octane ratings of cheaper grades any more. High octane gas got especially expensive. Airplanes, therefore, are still allowed to use leaded gasoline (known as AvGas), and octane ratings of 100 or more are commonly used in super-high-performance piston airplane engines.

[srkruzich]

I remember leaded gas, and compression ratio's of 10.5:1 and 11:1.  You can't even run a engine on gas these days. 

[Catwoman]

Gas is down to 1.599 here...I used my Dillons card and got my fill up for only 1.499/gal...Only .05 more than Christmas time!  Even though I know this is a sign of how bad things are right now, I'm still grateful.  Every penny that stays in my pocket helps me out just that much more.

[DanCookson]

Sorry, been really slacking of late.....Will try to do better 


April-09 Crude is trading at $41.54.

Appears all the outer months are trading higher as well.  I haven't had a chance to do much reading or talk to Frank, but I would make a general assumption that there is fear of the weaking of our dollar to to all the stimulus and gov't producing capital. (printing money).