Stupid Geology Question...

[smirkymonkey]

Could all the oil drilling in the Middle East have anything to do with the increases in the number of Earthquakes in the region (Iran, Israel & Pakistan just recently)?

I know their are some faults in the area that would increase the risk of earthquakes occurring, but wanted to know if drilling operations could exacerbate the problem? Thanks.

[RC]

1. Drilling, no.

Extracting the oil and underground water -Yes!

[smirkymonkey]

2. Do you have a link to this or an explaination

as to how this may cause the plates to shift??

[A HERETIC I AM]

3. My understanding of the strata containing oil is tht it is like a sponge

a wet sponge, albeit a stony one. If you remove the water from a sponge, it still retains it's shape. They have been taking oil from under Texas, Oklahoma and Pennsylvania for over 100 years. As far as i know, that hasnt had any adverse effects on plate tectonics.

[happyslug]

4. The simple answer is No.

The Simple answer is NO, oil is a liquid and should not have any affect on earthquake activity (Or at least earthquake activity that affects people).

Now we have to understand HOW oil is form. First oil is from plankton that thrived millions of years ago in some shallow sea far from land (as you near land seaweed gets mixed into the mix and helps turn the plankton to natural gas instead of oil). These plankton die and fall to the bottom of the shallow sea. Subsequently to the plankton a layer of limestone (or other porous material) is laid on top of the dead plankton, and on top of the limestone some sort of cap must exist (Generally salt but can be clay or other non-porous material).

If you do NOT have the above, oil can not happen. If no Plankton, no base for the oil. If not enough substance above the plankton not enough pressure to convert the plankton to oil (Also if to much substance i.e. the oil drops below 18,000 feet no oil, for the heat of the earth converts it to Natural Gas). If no limestone, no substance for the oil to seep through and gather together as oil is made by the earth from the dead plankton. If no cap, nothing to prevent the oil from going to the surface and being destroyed by oil eating microorganisms.

Thus you have to have all three. In Texas, Oklahoma and Louisiana, you had the shallow sea, the limestone and salt domes as caps (In Pennsylvania the caps tend to be clay).

Now plate tectonics also come into play, as the Plates moved over the last several million years, the movement did not affect the oil fields unless you had two Plates hitting each other. Both Pennsylvania, Texas and the rest of the US Oil Fields were on the North American Plate which has moved westward since what is now the Great Plains was a Shallow Sea. Thus no earthquake areas in the areas of the shallow sea (Through you did have some in California as the North American Plate pushes into and onto of the Pacific Plate making the Mountains of the West).

In the Mideast, the African plate is splitting in two along the Rift Valley of Africa. This split goes from the center of Africa where the Nile valley, flows north goes south and east of Egypt through the Red Sea and than continues north through the Dead Sea and the River Jordan.

You also have the induction of the Indian Continental Plate (India in the time of the Dinosaurs was an Island Continent, but has since rammed itself against the Asiatic Continental Plate). This interaction between these two plates is forming the Himalaya Mountains and the Mountains of Iran.

Thus the earthquakes of the Mideast (mostly Iran) is being caused by the above. i.e. First the affects of the Indian Plate going under the Asiatic Continental Plate and Second the affect of the
African Plate separating along the Rift Valley, the Red Sea, and the Dead Sea.

As to oil the movement (and interaction) of these Continental Plates shifted the limestone so that the oil could flow through large areas of Limestones and pool under large caps producing the Super Elephants of the Mid-East.

This was unlike the United States where you had little affect on the oil fields by the movement of the Continents and the main geological event that affected the oil fields was the subsequent drying out of the Shallow Sea of the Great Plains and formation of rivers that cut through the various caps when the Great Plains was dry land. These cuts permitted oil to escape from under the earth, but only in areas under the Rivers. In the areas between these river cuts the caps remained keeping the oil beneath them “safe”.

The Great Plains went through several periods of being a shallow sea than becoming dry land again since the original Shallow Sea that produced the oil that use to be underneath Texas, Oklahoma, Louisiana and the other states. Each time the Great Plains dried out new rivers were form and more cuts in the “caps”occurred. It was do to these “cuts” that you had so many small oil fields in the US compared to the Mid-East.

Thus the US had numerous small fields, while the Mid-East tend to have just a few but very large fields. This comes up when you hear people say “If they would drill as many oil holes as they did in the US, they would find more oil”. The answer to that statement is NO, the US had many small fields caused by the above mentioned rivers, the Mid-East did not have subsequent shallow seas like the Great Plains, and when the Mid-East’s shallow sea dried out very few rivers made cuts. Thus the Mid-East tend to have very large fields compared to the US, but very few fields compared to the US (Overall more oil in the Mid-East than in the US)..

As to earthquake, the main earthquake areas are North, East and West of the oil fields (even away from the Iranian Fields which tend to be near the Iraqi border). In the North and East of Iran you have Earthquakes, just like you have earthquakes in Afghanistan and Northern India. All caused by the Indian Plate ramming into the Asiatic Plate.

You also have earthquake along the Mediterranean sea for that is close to the split along the Rift Valley (which also gives some earthquakes to Greece, through Greek and European Earthquakes tend to be caused by the divide between the European Plate and the African Plate more than the newer Rift Valley Split).

Thus while the area of Oil Production are in the same countries as some of these earthquakes, where the earthquakes occur and why they occur have little to do with the existence of oil under ground. Now the super elephant sized oil fields were formed by the same plate movement that is causing the Earthquakes (As the plates push against each other, the movement of the plates took the oil fields with them and stretched them out to form the super fields). Thus the oil fields tend to be behind where the plates interact while the earthquakes tend to be near where the plates interact.

I hope the above explain the interaction between the Earthquakes and the oil producing countries, but just look at a map, while Iran has had earthquakes, Iraq and Saudi Arabia has not. Iraq and Arabia are South and West of the area where the plate they are on is hitting the Asiatic plate (And east of the Rift Valley Split), while Northern Iran is in the area where the plates are interacting between each others, thus you have Earthquakes in Iran and Afghanistan but no so severe ones in Arabia and Iraq.

[smirkymonkey]

5. Thanks for your great answer!

:)

[Tims]

6. Any large scale change

such as pumping large quantities of oil out of the ground can and will alter local geology. They will not cause any change in the general tectonic movement, but they can have the local effect of changing the pressure along nearby fault lines. This could theoretically either cause an earthquake or prevent one. It could simply provide a sufficient nudge to cause the sudden release of tension already present in a fault line or it could act as a safety valve removing pressure so that the tension in the fault is released more slowly. Either way, the actual cause of the earthquake is still the tectonic movement, not anything related to oil removal. You either speed up the occurrence of an earthquake that was going to happen anyway, or you alter its intensity. The total amount of energy released over time at the fault remains the same, only the rate the energy is dissipated is altered (again - theoretically).

I think there have been some studies to see if the frequency or intensity of earthquakes is altered by the intensity of drilling and oil extraction near active fault lines. I don't know what the results of these studies are. There have also been concerns raised about setting off deep explosives used in geophysical oil exploration near major fault lines. Also an oil recovery technique called fracturing, were fluid is pumped under high pressure in order to fracture the surrounding oil bearing rock and thus offer higher oil yields, has come under scrutiny not only for possible ecological damage (the contamination of groundwater) but also for possible negative geological effects. I doubt that there is a definite link, but enough people are concerned to at least fund these studies.

Small earthquakes have been reported here in Texas that are the result of suddenly collapsing salt domes that have been pumped dry of oil. This is really only a more dramatic form of subsidence which is common in Texas where the earth is literally sinking around old oil fields. Many of the oil fields in east Texas are relatively shallow and the collapsing domes have such a significant effect at the surface that many oil companies are now pumping these old dry wells full of brine to prevent further subsidence (and possible future law suits).

[smirkymonkey]

7. Interesting, and thanks...

do you know how deep most oil wells go?? I was wondering also if the motion of the constant drilling (as opposed to just oil removal) would trigger an already volatile fault??

Ultimately, I am trying to find out that if we are aggressively drilling in a quake prone area, and a series of devastating quakes are triggered (say, by Halliburton, for example) what would be the political and energy related implications?

[happyslug]

8. No more than 18,000 feet

Or about 5000 Meters or about 3 miles. Below that level Oil becomes Natural gas by the heat of the earth.

Texas tend to be 1000-13,000 feet deep:

VICKSBURG FAULT ZONE FIELDS - "The oil-bearing trend consists of two plays, producing from depths of 3,800 to 7,100 feet in Frio and Vicksburg sandstone fluvial and deltaic systems."
http://www.tsha.utexas.edu/handbook/online/articles/view/VV/dovhs.html

CORSICANA OILFIELD - "The field produces from a pinch-out trap in an Upper Cretaceous sandstone reservoir at an average depth of 1,050 feet."
http://www.tsha.utexas.edu/handbook/online/articles/view/CC/doc3.html

EAST TEXAS OILFIELD - “On September 5, 1930, after the well reached a depth of 3,592 feet in the Woodbine sand, it flowed live oil and gas on a drill stem test.”
http://www.tsha.utexas.edu/handbook/online/articles/view/EE/doe1.html

PANHANDLE FIELD - “The well was completed on December 9, 1918 to a total depth of 2,269 feet where 10 million cubic feet of gas were produced daily”
http://www.tsha.utexas.edu/handbook/online/articles/view/PP/dop1.html

SPINDLETOP OILFIELD - “The Lucas geyser, found at a depth of 1,139 feet”.
http://www.tsha.utexas.edu/handbook/online/articles/view/SS/dos3.html

FRIO DEEP-SEATED SALT DOME FIELDS - "at a total depth of 3,536 feet in a Frio sand."
http://www.tsha.utexas.edu/handbook/online/articles/view/FF/doftg.html

HASTINGS OILFIELD. On October 1, 1958....Major discoveries have been in the Marginlina, Frio, and Vicksburg formation sands of the Oligocene epoch, ranging in depths from about 5,000 feet to 10,000 feet. The deepest well known to have been drilled at the field was drilled on the Brown Lease by Stanolind Oil and Gas Company in 1953. Its depth was 13,024 feet, and it cost $232,000 to drill.
http://www.tsha.utexas.edu/handbook/online/articles/view/HH/doh1.html

There are and were other fields but at 13,024 that is the deepest well in Texas (Over two miles deep). Also 18,000 feet could be drilled by the late 1930s, what prevented deeper wells was that people serached for oil not Natual gas til the Natural gas shortage of the 1970s.

[happyslug]

9. In Pennsylvania the well depths vary from 69 - 21,460 feet

1859 On August 27, Edwin Drake and "Uncle Billy" Smith struck oil at a depth of 69 1/2 feet along Oil Creek,just south of Titusville, Venango County.

1942 The Venango Development Corporation.... sank a 370 foot deep shaft at Franklin, the only successful oil "mine" ever attempted in Pennsylvania.

1974 The Svetz No. 1 well in Somerset County, owned by Amoco Production Company, set a Pennsylvania depth record by drilling to 21,460 feet.

http://www.dep.state.pa.us/dep/DEPUTATE/MINRES/reclaimpa/interestingfacts/CHRONLOGYOFOILANDGAS.html

[Tims]

10. Vibrations are annoying

I've known several people who have had drilling operations within 100 to 200 yards from their homes. The vibrations can be significant (cracked plaster, objects vibrating off of shelves, etc.) but it really isn't much more than living near a highway with heavy truck traffic. If the vibrations from drilling rigs could trigger an earthquake, the California freeway system would trigger far more.

The bottom line is that people have been drilling in quake prone areas for generations. No clear link between drilling and earthquakes currently exists, through there is no scientific reason to doubt that it can have and effect. Earthquakes are still the result of tectonic movements which drilling cannot effect. The only possible effect is that it could increase the frequency of quakes by prematurely triggering two plates under stress to fail. The resulting quake would likely be smaller that the quake which would have occurred if the strain was left to build and release naturally (though it might have taken a hundred years to do so).

[happyslug]

11. Water is the main oil recovery method

As you should know, oil floats on top of water. People have know this since man first mixed oil and water.

When oil fields are new, the oil tend to flow out at a good rate, but as more and more oil is removed, the rate of oil being pumps drops. One way to get this volume back up is to pump water into the field. Often what happens an oil field has many wells, the deeper ones are stopped from pumping oil, and converted to pumping water into the oil field. This is to lift the oil to the remaining wells. Thus as most fields ages, it contains more and more water. Thus you have one liquid replacing another liquid.

Now water has different characteristics from oil, but both are liquids and share more features than differences. Thus some of these fields are filled with water instead of oil i.e. the fields are NOT empty hulls, just filled with a different liquid. The effect on earthquakes and sinkholes are not as bad as if the old fields did not have ANY liquid in them. Just a note on Oil and its removal.

One comment, water is not added till after most oil fields are past their peak. Thus the fear that the Saudi Arabian oil fields are past peak production for the Saudis are pumping water from the sea into their wells to keep production up. This is one of the reason some geologists believe the Saudis are at or past peak production.

[smirkymonkey]

12. Interesting, Thank you

Everyone.