Saturday, January 19, 2002
10:41 AM LINK
The Torrey Canyon Disaster
Last week I went on at length about supertankers, especially discussing the size of the global fleet and the typical storage capacity of a typical tanker, which is between one and two million barrels.
I mentioned a couple ships by name, including the infamous Exxon Valdez, which everyone knows, as well as the Jahre Viking, the largest supertanker in existence, which holds about four millions barrels.
But no discussion of supertankers would be complete with a mention of the Torrey Canyon. The Torrey Canyon is important because it was the first major oil spill by a tanker in history.
It happened in March 1967. The Torrey Canyon wrecked on the Isles of Scilly, off Land's End, the "toe" of Great Britain. It was laden with about 860,000 barrels of petroleum from Kuwait. It was a typical full load for a tanker of its day (not really a supertanker, by today's standards of a VLCC).
The accident was due to navigation errors and negligence by the captain. The ship ran aground on Pollard Rock and broke up. It burned for days. The entire cargo of oil was released in the ocean. Eventually the Royal Air Force had to bomb the ship to clear it from the rocks.
Here's a good summary about facts about the ship and the accident.
The spill formed three distinct oil slicks spreading in different directions. There is a good write up about the behavior of the slicks here. It has links to other information about oil slick behavior.
To quote from this page:
The oil leaked from the ship (31,000,000 gallons) and spread along the sea between England and France, killing most of the marine life it touched along the whole of the south coast of Britain and the Normandy shores of France, and blighting the region for many years thereafter.
Because nobody had planned for this, all sorts of emergency measures were attempted, many of which made matters worse; lots of chemical dispersants were eventually sprayed onto the oil slicks, but these were more lethal for life than the original oil.
As one might hope, the distaster lead to a number of reforms in the oil shipping business, including an increase in the liability by shipowners for the damage caused by such incidents.
Here is a good page about marine disasters and their influence on law and procedure.
Thursday, January 17, 2002
5:35 PM LINK
Apologies
Sorry to anyone who might possiblity be reading this blog (I know there are few, if any). I got sort of carried away with posting the last few days. I'm taking a break from other projects and was filling up my time these last two days with this. In any case, I'm going to take a break for a couple days from posting here, now that I've figured out how much oil a billion barrels is.
Will return on Tuesday, Jan. 21
5:23 PM LINK
U.S Supreme Court on Supertankers
Drilll down on Google far enough and you can find anything. This is a translated PDF of a Supreme Court decision in the two cases U.S v. Locke, Governor of Washington, INTERTANKO v. Locke, Governor of Washington (981701, 981706), from Oct. 1999 (not being a lawyer, I don't know how to cite the case in proper format).
Here is a relevant passage, as delivered by Justice Kennedy:
...by 1998 the number of vessels considered "tankers" in the merchant fleets of the world numbered 6,739, see U. S. Dept. of Transp., Maritime Administration, Merchant Fleets of the World 1 (Oct. 1998).
Now that's the kind of information I like. Here the 6,739 figure does not mean "supertankers." There are far fewer VLCCs. Kennedy also notes that at the time of the decision, INTERTANKO hauled about 60% of the oil imported into the United States.
I think I will download and read the entire PDF. It seems like a landmark case involving oil spills.
There's another site here on the case. I guess the jist of it was that Washington had enacted some laws regarding qualifications on tankers and their crews enterring Washington ports. The Supreme Court basically said that Washington law is pre-empted by federal law in this case, and that Washington should re-examine its laws in light of this.
5:23 PM LINK
The very first VLCC
According to INTERTANKO's Summer 1999 newsletter, the world's first VLCC supertanker was the Idemetsu Maru, built in 1966 by the IHI Shipyard in Japan. It had a capacity of 206,000 deadweight tons.
Despite that Exxon definition earlier, I see 200,000 dwt more and more as the threshold figure for VLCC supertankers. I'm going to use that from now on.
The site also states that since 1966, over 1000 VLCC and ULCC ships have been built, most of which were built early on.
That's a theme you see frequentl about supertankers: the global fleet is getting old, with average age now being over twenty years. Evidently there is a push to build more, but the shipyards (mostly in Japan and South Korea) are already running at full capacity.
5:22 PM LINK
INTERTANKO Fact Sheet 2001
Just ordered their fact sheet online through the INTERTANKO web site. It cost me 0.00 dollars, and it was supposedly available to non-members. I left my credit card information blank, but everything still worked with the shopping cart check-out. Wonder if it will actually show up all the way from Norway.
5:22 PM LINK
Current Market Rates
INTERTANKO has a nice page show current rates for renting a VLCC, in case you need to know.
Revealingly, it also gives the exchange rates between the Japanese Yen and the U.S. dollar, and also the South Korean Won and the U.S. dollar. That tells you what countries are important when it comes to the supertanker supply.
5:21 PM LINK
Current Market Rates
INTERTANKO has a nice page show current rates for renting a VLCC, in case you need to know.
Revealingly, it also gives the exchange rates between the Japanese Yen and the U.S. dollar, and also the South Korean Won and the U.S. dollar. That tells you what countries are important when it comes to the supertanker supply.
5:21 PM LINK
INTERTANKO
O.K. Now we're getting somewhere. Some real facts. I found this newsletter from INTERTANKO, the International Association of Independent Tanker Owners, which is based out of Oslo, Norway and was founded in 1971. Their newsletter is called, appropriately enough, Tanker.
In their newsletter they state;
As of April 1, 1999, the fleet of INTERTANKO's 270 member companies comprised over 2,000 tankers totalling 172 million tons deadweight. INTERTANKO members now account for 75 per cent of all independently owned tanker tonnage worldwide. Currently, about 76 per cent of the global tanker fleet is independently owned, a percentage which continues to rise.
Unfortunately, the rest of INTERTANKO's site is not that helpful. Most of the interesting pages are limited to INTERTANKO members.
Using these figures, you start coming close to the figure of 4,500 for the global fleet, as mentioned earlier.
From the figures above, it would appear. That INTERTANKO claims its members can haul a total of 1.3 billion barrels of oil. All the independent tanker operators together could haul about 1.7 billion barrels. Adding in the non-independent tankers, a rough estimate (since they don't provide tonnage figures, but fleet numbers) would give you a little over 2 billion barrels for the capacity of the global fleet.
That's quite a bit less than the 4-5 billion barrel capacity I estimated earlier. No doubt I was using too high a figure for the average size of the tanker. Probably much of the fleet consists of smaller vessels used for short runs.
In fact, using INTERTANKO's fleet as an example, the average tonnage around 90,000 tons deadweight, or about 650,000 barrels. Given that there are lot of vessels much larger than this, there must be quite a few little tankers, not even the VLCC class, that are carrying petroleum on the world's seas.
In any case, I'm now convinced that 2 billion barrels is a good estimate for the total capacity of the world's tanker fleet.
5:20 PM LINK
How Many Supertankers, Really?
According the BBC article I quoted earlier, I may have overestimated the size of the world's supertanker fleet. The article states:
The worlds fleet of supertankers, estimated at just over 400, are the main conduit for oil, travelling from oil producing regions to consumers.
The BBC's Roger White asked Pankaj Khanna, a researcher for the international shipping group SSY, if a shortage of supertankers is fuelling the present oil crisis, and why new tankers have not been built in recent years?
"That is not really true. There are three main sizes which carry the oil. You have the super tankers which we call the very large crude
carriers and the ultra-large crude carriers which carry oil from the Middle East gulf to the East and West. There are about 440 of those ships around. Then we have what we call the million-barrel ships which carry one million barrels of cargo. There are about 280 of those. Then you have the Afromax's which are generally used on the short-haul trades like from the North Sea to North West Europe or from Colombia and Venezuela to the United States gulf."
The statement is darn confusing. Are there 440 ULCC's or 440 ULCC's and VLCC's combined. And what are these "million barrel" ships. Shouldn't they be VLCC's too? I have a feeling there are very straightforward answers, but things are getting mangled during the writing of the articles.
5:19 PM LINK
Half a Billion Barrels Through Houston
From Mitchell Energy and Development, an independent producer of natural gas and natural gas liquids, I have learned that as of 1998, the port of Houston was receiving about half a billion barrels of crude petroleum annually.
5:19 PM LINK
Rent a Supertanker
Curious about how much it costs to ship oil? I found this from the website of the Canadian Center for Maritime Communications, dated March 2000:
Supertankers of more than 250,000 dwt are pulling in nearly $27,000 (US) a day compared with a 1999 average of about $21,700 (US).
The abbreviation 'dwt' stands for 'deadweight tons' of course. So we're talking about a large VLCC here.
The price for hiring a supertanker is very volatile. Six months later, the BBC reported:
The cost of hiring a supertanker has reached $60,000 a day, the highest since 1973. Shipping analysts in London say the rate is likely to reach $80,000 a day before the year is out.
5:18 PM LINK
The Global Fleet of Supertankers
Finding information on-line about the size of the global supertanker fleet has been strangely difficult. So far, all I have found is this one paragraph from the National Resources Defense Council about underwater noise pollution at U.S. deepwater ports.
This year 1,500 petroleum tankers, one-third of the global fleet, will enter U.S. harbors: 8,000 stops expected for New York and New Jersey, 10,000 for Galveston, Texas, and 3,000 for San Francisco (to name a few ports of call). And each sweep through U.S. waters adds to our domestic noise pollution problem.
So there you have it: according to this paragraph, the global fleet of crude carriers comprises about 4,500 supertankers.
How much would they hold all at once? Let's suppose an average about 150,000 tons, a typical midsize VLCC. Each would carry around a million barrels.
Thus the global fleet could carry somewhere in the ballpark of four to five billion barrels of oil at once.
By the way, no wonder it was so hard to find this number. The reference from the above article about the number of supertankers in U.S. ports says this:
Personal communication from LCDR Frank Elfring, U.S. Coast Guard (July 30, 1997) (Coast Guard transit data for eight major ports, from 1990 through the first quarter of 1997).
It seems you have to know a high-ranking Coast Guard officer to get access to these figures. It's got to publicly available somewhere, doesn't it?
Wednesday, January 16, 2002
11:23 PM LINK
The Jahre Viking
The calculations about the capacity of the massive ULCC supertanker was pretty much correct: about four million barrels.
I just learned that the largest supertanker in existence right now is the Jahre Viking, which has a capacity of 564, 763 deadweight tons, or about 4.1 million barrels.
The Jahre Viking was actually struck by Iraqi forces during the Iran-Iraq war in 1988. She was declared a total constructive loss and was laid up in Brunei for months. Now she makes regular trips between the U.S. and the Middle East.
The Jahre Viking is the largest man-made floating object on earth. Click here to see a good picture of the dimensions of the ship.
11:06 PM LINK
The Exxon Valdez
To Americans, the most infamous supertanker is certainly the Exxon Valdez, which struck the Bligh Reef in Prince William Sound on March 23, 1989, just after leaving Port Valdez fully loaded with north slope crude oil.
Most crude oil ports cannot accomodate the massive ULCC supertankers. Port Valdez is an example. A typical supertanker coming and going from Alaska is a VLCC with a capacity between 100,000 and 200,000 tons.
The Exxon Valdez was carrying a full load of about a 1.3 million barrels at the time it struck the reef. A little under a fifth of that was spilled into the sound, about 260,000 barrels.
10:25 PM LINK
Supertankers
It is useful to translate a billion barrels into a mental picture.
Specifically, how many supertanker loads does it take to haul a billion barrels of crude oil?
The capacity of any ship is actually measured in units called deadweight tons. This is because in hauling cargo on the water, you have worry about how much it weighs, not just how much space it takes up (i.e., gallons and barrels).
Ton here refers to long ton, which is exactly 2240 pounds. How many barrels of crude oil in one ton? There is no exactly figure, since this depends on the density of the oil, which varies. But the rule of thumb is
1 ton = 7.4 barrels = 311 gallons
Supertankers actually come in two sizes, large and very large. More specifically, one has:
VLCC (very large crude carriers), having a capacity over 100,000 deadweight tons.
ULCC (ultra large crude carriers), having a capacity over 500,000 deadweight tons.
The definitions are from Exxon and are found
here.
The ULCC are the monsters of the supertanker world. Let's use the threshold ULCC as our supertanker
Straightforward arithmetic then tells you than our "typical massive supertanker" can hold upwards of four million barrels of crude oil. A typical smaller VLCC tanker might hold between one and two million barrels of crude oil.
That is, our rule of thumb will be:
1 ULCC supertanker --> approx 4 million barrels
To answer the question, using our back-of-the-envelope calculationi, it would therefore take approximately 250 loads of such a supertanker to haul a billion barrels of oil.
That is,
1 billion barrels --> approx 250 monster supertanker loads
1 billion barrels --> approx 1000 small supertanker loads
An interesting (but somewhat outdated) reference on supertankers from 1975 can be found here.
10:19 PM LINK
Unit: Billion Barrel
For country-wide production and figures, the typical unit is a billion barrels.
10:18 PM LINK
Unit: Barrel
Oil capacity is typically measured in units of barrels. One barrel is exactly 42 U.S. gallons.
8:13 PM LINK
The Century of the Environment
"We have entered the Century of the Environment, in which the immediate future is usefully conceived as a bottleneck: science and technology, combined with foresight and moral courage, must see us through it and out..."
Edmund O. Wilson, from The Future of Life, reviewed in this month's Scientific American Contains an interesting hypothetical dialogue between an economist and an environmentalist.
6:03 PM LINK
U.S. vs. OPEC
I mentioned how OPEC is not always very effective at exercising its cartel muscle, and is at the moment being somewhat undercut by Russia (this should change next week, of course). But I should also mention that the U.S. is definitely not in a position to undercut OPEC at all. In case oil prices were to get too high, we can no longer "turn on the taps" and bring oil prices back down to levels we like.
Of course, the Russians would always help us out by bringing oil prices down a bit. The Russians have always been our friends.
We could include that as another feature of the "naive energy independence" picture: depending on the Russians to come through for us in a time of crisis.
4:07 PM LINK
The "President" comes out against Arctic Drilling
President Barlett's long-awaited policy statement has been released. C.J. to appear tonight on Fox News explaining the details.
4:00 PM LINK
A Cynic's Interpretation of our Iraq Policy
This is not necessarily my opinion, but it's not an unreasonable at-a-glance conclusion: domestic oil producers actually love OPEC because it keeps crude oil prices high for them. It's a win-win situation: our local guys make better profits, but the foreigners get blamed for it.
An embargo on Iraq, with its enormous reserves, helps out OPEC by letting the other OPEC countries (our "friends") produce at higher levels (making more profits for themselves) while still keeping oil prices relatively high (pleasing everyone in the oil business).
I'm not saying this is what is going on. Probably there are plenty of counterarguments. But at first glance, you'd almost believe that the oil companies were running our entire government and our foreign policy.
3:55 PM LINK
Impotent OPEC?
When I said OPEC can control world prices, that's only if they truly act like a cartel. What I should have said is that most of the time, they control the range of range prices, somewhat weakly. They have the potential to completely control prices, just as they did during the embargos of the 1970's, but most of the time lately, they aren't very good at it.
When they fail to act as a true cartel (i.e., when certain member states break the quotas and keep production high), then other non-OPEC countries can bring the world market price down by increasing their own production levels. Lately, that's what's been happening with Russia, which has been undercutting OPEC. This is only possible because OPEC has been in mild disarray.
Of course this doesn't preclude OPEC from getting its act together and exercising its cartel muscle at any time in the future.
Note that the increased production of Russian oil doesn't necessarily mean that Russian petroleum is going into your gas tank. All that matters is that it is out on the world market. Prices fluctuate according to the total amount on the market. The world oil market isn't perfectly fluid, in that oil doesn't travel frictionlessly (pricewise) around the globe. It has to be transported. But our transportation of petroleum is very sophisticated, beause there's so much money to be made by it.
3:42 PM LINK
Strange Voices of the GOP
Here's an interesting statement from Republicans for Environmental Protection about developing real "energy independence." It's an open letter to Bush. It's actually anti-ANWR-drilling.
1:10 PM LINK
Fake Independence
The fact that OPEC controls prices for oil drilled right here in the U.S. means that when you hear someone talk about "energy independence," it's important to figure out what they really mean.
Do they just mean: drill enough oil here that we don't need any imports? First of all, this will never happen. Most of the oil in this country has been recovered already. Most of the great oil provinces in the U.S. were already discovered by the 1930's, even the ones in Alaska. The last major domestic oil field to be confirmed was in 1968 at Prudhoe Bay (contrary to the dynamics promoted by many economists, higher prices in the late 1970's did not result in major new domestic finds, by the way).
The only way we could live on domestic oil alone would be through extremely radical conservation efforts. How would these be instituted? By government fiat, or by a World War II-style "do it for America" campaign?
But even if radical conservation of oil could be achieved (and maintained), OPEC would still control the price of all domestic oil. That's because the oil we recover here in the U.S. is a free-market commodity, and can be bought and sold on the open market.
For example, there is nothing to prevent all the oil recovered from any ANWR drilling from going straight to Japan. The restriction against exporting Alaskan crude was lifted in 1995, and its restitution is strongly opposed by the Alaska Congressional delegation.
Why not institute legislation to force oil producers to sell domestically recovered oil only to U.S. consumers, and only at a predetermined "reasonable" rate independent of what OPEC is charging?
First of all, if the rate were below market prices, drilling would decrease and perhaps stop altogether. Oil companies would want to put their resources into drilling where they can make the most money, e.g., in the Middle East.
You would have to subsidize the cheap prices somehow. That is, the federal government would have to pay oil companies the difference between the the "reasonable" rate and the current market rate, determined by OPEC.
Another alternative would be to nationalize the domestic oil industry.
So there you have it, "energy independence" through oil alone would require both (1) radical conservation measures through either legislation or patriotic fervoir, and (2) large government subsidies to the oil industry.
That is, everyone drives miniature cars while the oil companies reap large tax-payer subsidized windfalls (or get taken over the government altogether). Keep this scenario in mind when you hear someone on talk radio naively going on about "energy independence through more oil drilling".
I say, "Bring it on!"
11:38 AM LINK
Attack on Bush from the Right
Here's an interesting piece from Jerry Taylor at the Cato Institute. It was written before the election. It illustrates some interesting points about Bush's thinking on oil, and how it is far from being "free-market."
One thing to keep in mind is that OPEC sets world oil prices. This is true for both oil they produce and oil anyone else produces. They control the price as a cartel by the overall production level.
The important point is that even if the US drilled 100% of its own oil supply (an impossiblity, so long as oil accounts for almost all our energy supply for transportation), the domestic price of that oil would still be set by OPEC.
That's right. ExxonMobil will always sell Alaska crude at whatever OPEC decides its worth, independent of how where it is being used.
This is the dirty secret: oilmen in the U.S. (ones like Bush) like OPEC. It keeps prices high for them. If OPEC weren't keeping prices high for them, they wouldn't be able to drill and make a profit.
11:23 AM LINK
2000 Acres?
Here a good page about the 2000-acre hoax, i.e., the idea that that is the total area that will affected by drilling exploration in the ANWR.
11:13 AM LINK
ANWR
Another thing I want to explore in this blog in the proposal for drilling in the Arctic National Wildlife Refuge. This is is somewhat of a companion issue to the world oil supply topic.
In general, whether or not we (through the Congress) allow oil and gas drilling in ANWR will not have a significant impact on overall world oil production and when it begins declining. I don't have the numbers at hand, but I will.
Nevertheless, it's a pretty hot-button issue. My bias is to not drill, not based on biodiversity arguments, but arising more from my belief that some places should just be left alone, and the ANWR may be one of the them. But actually it is not that strong of a bias. If allowing drilling there could be part of deal to protect other lands (I mean really protect them) then maybe it would be worth it.
At heart, I'm a deep ecologist, but one who loves cities and civlization as well.
2:39 AM LINK
Reservoir Rock
I guess I mentioned before that oil is not drilled from the rock in which it produced. The droplets from the source rock migrate underground, collecting into a liquid reservoir.
When the oil is in a reservoir, it is still inside rock, however. It's not like there's a big empty chamber underground filled with liquid petroleum.
The rock in which the oil collects is called reservoir rock. Typically reservoir rock is
sandstone. In a oil reservoir, the sandstone is saturated with oil, to a much higher degree than the original source rock. Sandstone is very porous and permeable, and thus it can hold a large reservoir of liquid.
Typically the same sandstone reservoir rock that holds oil will also contain water and natural gas. As you know oil floats on top of water, and this is true in the reservoir rock as well. Typically the oil will be found floating on top of the water, even though both are inside the saturated sandstone rock.
Water-laden andstone provides the reservoir rock for many of the great aquifer systems in the world. If you were picturing underground aquifers as big cavern systems, like a cistern, you were wrong. The water is held in rock.
The same is true of oil. It's just that the rock holding oil is not the rock that produced the oil. The distinction becomes important when you're looking for the right kind of rocks that produce oil.
If you're drilling for oil and you hit water, it is sometimes a sign that you've drilled too far. If you haven't found oil yet, the water could be telling you that there is no oil and that you've found a "dry" hole. This is one circumstance where water doesn't preclude the term "dry".
Sandstone is, of course, a sedimentary rock. MIneralogically speaking, it is composed mainly of quartz and feldspar.
Tuesday, January 15, 2002
4:17 PM LINK
The Horse's Mouth
I should have said that the Oil and Gas Journal is not only one of the most important, but is widely considered the most important trade publication in the petroleum business.
The main reason for this superlative claim is that the OGJ is considered to be the authoritative source for how big the world oil reserves really are, which it publishes annually on a country-by-country basis, at the end of each calendar year. The numbers they publish form the basis of much government and industrial policy around the world.
The realibility of these estimates, however, is a big source of contention in the study of petroleum supplies. It's a point that we shall examine in great detail in the future.
3:05 PM LINK
Petroleum Newsfeed
As one can see along the left-hand side, I have reinstated the newsfeed on this blog. Of course, the newsfeed will concentrate on news items about the petroleum supply, and related items, including alternative fuels. That is, I won't be posting stuff about fluctuations in the current market or price of oil, only things about the long-term picture. It will probably take a few weeks to settle into a groove of what items are important. If anyone knows of any other good sources for such items, by all means tell me.
The first couple items I posted are from the Oil and Gas Journal, one of the most important trade publications in the petroleum business.
1:50 PM LINK
Martian Oil, Inc.?
As I mentioned before, sedimentary rock seems to have been discovered on Mars, strongly supporting the idea that water was once present on liquid form on the planet's surface.
But from the fact that oil source rock must contain sufficient organic molecules as well, it should be pretty obvious why one wouldn't expect to drill gushers on Mars: the discovery of oil reserves on Mars would be tantamount to the discovery that life once existed there. Some people believe this is possible, of course. Although it is not out of the question, it would be revolutionary if true.
Not surpisingly, some people are already looking forward to the challenge of petroleum exploration on the Red Planet.
Personally I hope that if we indeed were to make such a discovery on Mars, that by the time we do, we won't even need to drill for crude petroleum, except in the interests of pure science.
1:06 PM LINK
My Real Biases
As I stated before, I have a bias towards advocating rational approaches to the growth of suburbs, preservation of biodiversity and wilderness, adoption of alternative fuels, and transportation that is not exclusively by automobile.
One would think this would mean that I'm already convinced of Deffeyes' thesis that world production will begin declining within the next five years, simply because I want to believe it. Perhaps this is true. If so, I have to fight against it while reading the book. Deffeyes himself mentions that he has never known anyone to change his or her mind on this topic.
On the one hand, it seems like a decline in world production would be just what the doctor ordered for our civilization. It would have the potential to launch incredible upheavals in geopolitical and capitalistic structures. It would prompt the rapid adoption of other sources of fuel as nothing else could. All the "bad people" would "get their due" and gnash their teeth in agony because they did not believe those of us who saw this coming.
On the other hand, as tempting as it is to look forward to this, it has a few drawbacks. I've learned that at heart, I'm basically a fairly conservative person (with a small 'c'). I like stability. Whenever I want change, I move or visit a new place, but I like to know that the places with which I am familiar will "always be the same."
Of course they won't stay the same. Nothing is permanent. But many of the disruptions that would occur from a decrease in world oil production in the next few years would "change my world" in drastic ways that do not seem completely appealing.
Although I detest always having to use an automobile, sometimes cars can be just the ticket. Sometimes you want a good powerful one that will climb over rocks and snow, or carry a heavy load, or go up a steep hill. My wife is partially disabled, and the use of a car is freedom to her, even more than it is for most other Americans. Some of my favorite moments in life have been on road trips in a car.
What would become of my career and my personal plans for acquiring wealth and property if the oil market went haywire? Do I really want to "live in interesting times"? Do I want my parents to have to cope with the changes in their lifestyles?
In that regard, maybe my real bias is an idealistic one, towards the peaceful adoption of new technologies, not one forced by sudden, drastic change. In that regard, I'm no sure what I "want" to believe about Deffeyes' thesis. My realistic side said that nothing will change unless it is forced. Maybe it's me who needs to be forced to adopt new technologies by a changing world. But maybe I want him to be wrong. I'm not sure.
I hope this helps me to be more impartial in evaluating this topic.
Monday, January 14, 2002
6:07 PM LINK
The Living Rock
Besides its physical properties, petroleum source rock has another requirement of which you are probably already aware: it has to be sufficiently rich in organic material.
In this case, organic material means "molecules remaining from decayed living organisms." If you remember any of your basic organic chemistry, organic molecules are typically composed of various highly-sophisticated combinations of four elements:
1. hydrogen
2. oxygen
3. nitrogen
4. carbon
(by the way, it's very useful to recite them in that particular order).
Of course other elements are sometimes present too (for example the iron atoms inside hemoglobin molecules in your blood), but for the most part, you can picture the rich variety of life as arising from the highly intricate way in which carbon atoms bond with the other three elements just mentioned.
The carbon-based organic molecules inside plants and animals are typically quite sophisticated. Even a "simple" organic molecule like glucose (your basic sugar molecule) or caffeine seems complicated to the untrained eye.
Click here to see a glucose molecular diagram. (Don't worry if you're not chemically inclined. You won't be tested on this). As is the convention in organic chemistry representation, carbon atoms are assumed to exist at the unidentified junctions of the lines.
T-shirts and coffee mugs depicting the caffeine molecule are popular "geekware" around chemistry departments and biomedical labs.
As organic molecules go, the most complicated structure is definitely the DNA molecule, consisting of millions of atoms, the exact chemical composition of which varies from one living being to another.
Compared to a DNA molecule, glucose and caffeine are extremely simple. DNA is such a complicated and vast molecule that one cannot even use traditional molecular models of the individual atoms to describe it. Instead you can only describe in terms of larger building blocks. Drawing a DNA molecule in terms of its individual atoms would be like drawing a map of the world and trying showing every house on every street. Instead you just show countries and cities.
But in the case of oil source rock, we're not talking about anything nearly sophisticated as DNA The organic molecules typically inside source rock are the most basic organic compounds possible, simpler even than glucose or caffeine.
Specifically, the source rock organic molecules are the basic hydrocarbons. They are composed of straightforward bonded combinations of carbon and hydrogen.
Click here to see some of the most basic hydrocarbon molecules. The hydrocarbons in oil source rock include these ones, as well as ones only slightly longer and more sophisticated.
These simple hydrocarbons are what is left over when just break down the much more complicated molecules present in living tissue. It's like taking a big tinker-toy structure and smashing it down into smaller pieces. You can imagine the resulting pile would have only basic combinations left.
That's what the simple hydrocarbons are: basic organic pieces. If sedimentary rock with the right physical properties also is sufficiently rich in these simple hydrocarbons, then it might produce recoverable oil.
11:44 AM LINK
Porousness and Permeability
Two physical features of sedimentary rocks that important in the formation of crude petroleum are porousness and permeability.
The porousness of a rock formation (usually a layer within a sedimentary stack, in the case of oil reserves) is basically the volume of the rocks that is taken up by pores, i.e., holes, inside of it. Pores are the pockets inside the solid rock in which oil droplets can form. Without a suffiicient content of pores, there would be no space for the liquid droplets to form.
Besides porousness, the rock must be sufficiently permeable. Permeability is an measure of the connectedness of the pores. This connectedness allows the liquid to travel through the rock once it has been formed.
Even if a rock has plenty of pores, if they are not sufficiently connected, then the isolated drops within the pores won't be able to migrate through the rock and gather together in a liquid reservoir, which is necessary for the oil to be recovered by conventional drilling methods.
If pores in a rock are like rooms in a house, then permeability is indication of how many hallways and doors there between the rooms. A rock that is porous without being permeable is like a house with rooms but no way to get in or out of them.
For obvious reasons, porousness and permeablity of sedimentary rocks are also imporant considerations when building a dam. Here's an interview with Floyd Dominy, former Commissioner of the U.S. Bureau of Reclamation, about the building of the Glen Canyon dam. He mentions how porousness is important in selecting a dam site. He probably means both porousness and permeability in this case. Of course, in the case of a dam, you don't want the rock to be very permeable.
In the case of pertroleum source rock, however, permeability is a good thing.
Sunday, January 13, 2002
5:31 PM LINK
Liquid vs. Rock
Crude oil is a liquid, right? So how is that one speaks of rocks when talking about the source of oil?
The key is to remember that the rocks are the source of the oil. Petroleum geologists always speak in terms of source rock.
The oil is produced in the rock, but to be recoverable, at least by conventional means, it can't stay in the rock. It has to seep out of the rock and into liquid reservoirs below ground.
The underground reservoirs from which liquid petroleum is recovered can be either above or below the original source rock. Deffeyes uses the analogy of a kitchen sponge. When you squeeze a sponge that is full of water, water can come out of both the top and the bottom.
The same is true of source rock when it gets squeezed underground. The small oil droplets that were formed in the rock gets squeezed out, either up or down, and collect together into the liquid reservoirs that form oil reserves.
