Gulf of Mexico

Plugging Macondo, the story of how the runaway Deepwater Horizon oil well was finally brought under control

Last May I wrote about the oil drilling disaster in the Gulf of Mexico. This year I can report on the final killing of the runaway well. The story appears in the Spring issue of Mines Magazine, the magazine of the Colorado School of Mines Alumni association. The story appeared there because the two engineers in charge of the operation, Donal Fitterer and Bill McEduff, are graduates of “Mines.” You can read their story here.

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The well was plugged at the top, but top plugs are often temporary solutions. What was really needed was a relief well to intersect the hole just above the oil reservoir, the so-called “bottom kill.” All they had to do was hit a basketball-sized target buried under 5,000 feet of water and 13,000 feet of rock while drilling from a randomly moving floating platform. Sounds like a high-pressure assignment, but Fitterer said, “The number one thing I learned at Mines was the ability to focus on exactly what needs to happen to get the job done. They are very big on giving you too much to do, so you have to make a decision as to what is most important.”

The technique they used was to drill the relief well, using standard directional drilling, to get close to the well at a depth. Once there, they used a ranging vector magnetometer to close in on the target which involves drilling a little, putting the instrument down the hole, then adjusting and drilling some more. The goal was to get the relief well parallel to and near the original well, then intersect the runaway well at a depth near 18,000 feet, which is just above the oil reservoir.

Positioning is achieved using a 300-foot-long assembly, which includes a 30-foot-long cylindrical beryllium copper tool equipped with a transmitter and receiver on opposite ends. Invented by Vector Magnetics, the device emits a current that sets up an electromagnetic field when conducted by the well casing. By interpreting data on the electromagnetic field picked up by the receiver, Fitterer can calculate the precise distance and direction to the blown-out well.

It only takes him two or three hours to collect these measurements, but they must be taken every 30 to 60 feet, and getting the equipment into place at the extreme depths at which they were operating was a very time-consuming process: 24 hours to withdraw the drill bit; 12 hours to lower the ranging tools, take measurements, and retrieve the equipment; and another 24 hours to lower the drill bit back into place. As a result, in the final approach, progress moved at a rate of 30 feet every 2 ½ days.

Once the original well is intersected, they could pump in heavy mud to permanently seal the well. You can watch an explanatory video of the technique here.

Gasoline Prices and the Obama Energy Policy

When President Obama took office, the national average gasoline price was $1.83 per gallon according to the Energy Information Administration. As of this writing, the national average gasoline price is $3.39 per gallon. There are many factors that determine the price of gasoline, not the least of which is turmoil in the Middle East. The price depends on supply and demand and upon the expectations of supply and demand.

I don’t know if the Obama administration is simply clueless on energy, or if there is a determined ideological effort to cripple fossil fuel supplies in order to promote renewable energy, but the effect of administration policy is to discourage and hinder domestic production of fossil fuels.

In September, 2008, soon to be Energy Secretary Steven Chu told the Wall Street Journal, “Somehow we have to figure out how to boost the price of gasoline to the levels in Europe.” Gas prices in Europe averaged about $8 a gallon at the time.

Contrary to administration rhetoric that the U.S. should become more energy independent, administration policy seems to be directed to do all it can to stifle domestic production.

Following the Deepwater Horizon accident in the Gulf of Mexico, the administration imposed a drilling moratorium. That moratorium was lifted last October, but in fact still remains in force. The Interior Department has approved just one drilling application although more than 100 are pending. A federal judge ordered that the de facto moratorium be lifted but the administration has ignored that order. In fact, in early February, the federal judge held the Interior Department in contemp of court for dismissively ignoring his ruling to cease the drilling moratorium which the judge had previously struck down as “arbitrary and capricious.” Ironically, the de facto moratorium of Gulf drilling will deprive the federal government of $1.35 billion in royalties this year.

According to the Heritage Foundation, “Obama also reversed an earlier decision by his administration to open access to coastal waters for exploration, instead placing a seven-year ban on drilling in the Atlantic and Pacific Coasts and Eastern Gulf of Mexico as part of the government’s 2012-2017 Outer Continental Shelf Program.”

 The U.S. has abundant resources of oil and natural gas in shale deposits. According to the U.S. Geological Survey the U.S. holds more than half of the world’s oil shale resources. The largest known deposits of oil shale are located in a 16,000-square mile area in the Green River formation in Colorado, Utah and Wyoming. The USGS’s most recent estimates (April, 2009) show the region may hold more than 1.5 trillion barrels of oil – six times Saudi Arabia’s proven resources, and enough to provide the United States with energy for the next 200 years. But Obama’s Interior Department is reversing Bush-era policy by delaying leases saying they need to take a “fresh look” at the situation.

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The EPA has added costly new regulations to refineries over concern with global warming. The EPA is also denying approval of the Keystone pipeline which would increase the amount of oil the U.S. receives from Canada by over a million barrels per day.

If all this were not enough, the Interior Department has instituted a new “wild lands” policy that will bypass Congress in establishment of wilderness areas which will further delay and restrict access to our mineral resources.

The next time you fill your car with gasoline, don’t blame the oil companies for the high prices, the fault lies squarely with Obama’s energy policy.

Origin of the Grand Canyon

The Grand Canyon of the Colorado River in Arizona is one of the world’s most awe-inspiring places. The canyon is 277 miles (446 km) long, 6,000 feet (1829 m ) deep from rim to river, and 18 miles (29 km) wide at its widest point.

The canyon cuts through the Colorado Plateau, a highland that has existed since the Laramide orogeny which built the Rocky Mountains beginning about 70 million years ago. The canyon exposes rocks which range in age from almost 2 billion years to 200 million years. The earlier sediments represent deposits in warm, shallow seas, while the younger layers represent desert sand dunes.

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The origin of the canyon has been the subject of geological debate. The following story, pieced together from several sources, most notably, the Arizona Geological Survey, is based on the most recent research and age dating.

The Colorado Plateau was uplifted to an elevation of about 2 miles (3.2km) above sea level. One theoretical study suggests multiple stages of subsidence and uplift related to plate tectonic movement.

The Plateau initially tilted to the northeast and rivers, including the ancestral Colorado River, flowed in that direction. Deposition of evaporites and the Green River formation in Utah and Colorado, indicate that these northeast flowing rivers emptied into a series of lakes which were mountain bound, similar to the Great Salt Lake in Utah. (See paleomaps here.) (Some researchers suggest that there was an outlet to the Gulf of Mexico.) Beginning about 18 million years ago, crustal stretching formed the Basin and Range province west and south of the plateau. Also around this time, plate tectonic adjustment began to tilt the Plateau toward the southwest.

Sometime around 10 million years ago, plate tectonic movement began to open the Gulf of California and a river at its north end began to cut northward. At about the same time, the northeastward flowing rivers of the Colorado Plateau reached the southern escarpment of the plateau and began to flow south forming lakes along what is now the course of the Colorado River. Actual cutting of the Grand Canyon probably began about 5.5 million years ago. The evidence and details of the story are continued now by the Arizona Geological Survey “Arizona Geology, Winter 2005.”

The Colorado River [now] leaves the Colorado Plateau at the Grand Wash Cliffs where it flows into Lake Mead. A long, north-south trending valley at the foot of the Grand Wash Cliffs, known as Grand Wash trough, contains lake sediments that were deposited between about 11 and 6 million years ago. While the lake sediments were being deposited, alluvial fans derived from highlands on both sides of the valley were deposited on the flanks of the valley. There is no evidence in these sedimentary rocks of a large river like the modern Colorado entering the valley. Indeed, if the modern Colorado had entered the valley, it would have quickly filled the lake with sand and gravel. A volcanic ash bed near the stratigraphic top of the limestone is 6 million years old, so the Colorado River must have arrived in this area after this time.

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South of Lake Mead the Colorado River traverses 400 km (250 mi) of low desert before arriving at th head of the Gulf of California south of Yuma. Deposit of the Bouse Formation record a brief but deep inundation of basins along the course of the river. The Bouse Formation consists of a basal layer of silt limestone that is typically one to several meters thick and is commonly overlain by up to hundreds of meters of siltstone and minor sandstone. These sediments were thought to have been deposited in an estuary of the developing Gulf of California after a U. S. Geological Survey (USGS) paleontologist first reported the presence of marine invertebrates in 1960. Estuaries generally have variable salinity conditions because, during times of high river flow, fresh water dilutes the salt water while sea water is dominant in times when river input is low. This leads to a mix of marine, brackish and fresh water organisms like those represented by the fossils in the Bouse Formation.

The Bouse Formation is exposed at elevations of up to 536 m (1760 ft), with elevations generally increasing from south to north. If in fact the Bouse Formation was deposited in an arm of the sea, then the lower Colorado River trough must have been uplifted by up to 536 m in the past 5 million years. USGS geologist Ivo Lucchitta proposed in 1979 that not only was the lower Colorado River trough uplifted in the past 5 million years, but that this uplift was part of a more regional tectonic uplift that carried the Colorado Plateau up to its current high elevation. Three discoveries in the past 10 years have cast doubt on the interpretation that the Bouse Formation was deposited in an estuary. In a paper published in 1997, Professor P. Jonathan Patchett of the University of Arizona and Jon Spencer of the AZGS showed that the strontium isotope composition of Bouse Formation limestone was similar to that of Colorado River water, and quite different from sea water. They proposed that the Bouse Formation was deposited by the Colorado River in a series of lakes that filled with river water and spilled over, eventually linking the river with the Gulf of California.

In 2002, during the course of a field mapping project in the Bullhead City–Laughlin area (Mohave Valley), Kyle House of the Nevada Bureau of Geology and Mines and Phil Pearthree of the AZGS discovered evidence that initial inundation of the northern part of the Colorado River trough was marked by southward-transported flood deposits. Such flood deposits would not be expected for initial inundation from sea water derived from far to the south, but they are consistent with an upstream lake spillover and initial influx of Colorado River water derived from the north in the Lake Mead area. These flood deposits are directly overlain by the basal limestone of the Bouse Formation. On the flank of the valley, they found a volcanic ash layer just below the Bouse Formation that was determined by Mike Perkins of the University of Utah to be 5.5 million years old. Bouse deposition was succeeded by a period of erosion, which was followed by deposition of at least 250 m (800 ft) of sand and gravel that is clearly associated with the Colorado River. This period of massive river aggradation ended about 4 million years ago, as another volcanic ash was found near the top of the river deposits.

Yet another volcanic ash indicates that the Colorado River had downcut at least 60 m (200 ft) below the level of maximum aggradation by 3.3 million years ago. Most recently, Rebecca Dorsey of the University of Oregon said that Colorado River sands first arrived in the Salton Trough south of Yuma 5.3 million years ago. Such sands would have been deposited before reaching the Salton Trough if any large body of standing water such as a lake or an estuary existed along the course of the Colorado River. The sand deposits thus reveal the existence of a through-going Colorado River by 5.3 million years ago and mark the beginning of an enormous influx of river sediment that has filled the Salton Trough since that time.

All of these recent studies are consistent with the concept that the Bouse Formation was deposited in a geologically short-lived chain of lakes that were created by initial influx of Colorado River water into previously closed basins. At the mouth of the Grand Canyon, the Colorado River first arrived less than 6 million years ago. Along the course of the lower Colorado River, it appears that all of the Bouse Formation was deposited between 5.5 and 5.3 million years ago and Colorado River sands arrived in the Salton Trough less than two hundred thousand years after deep flooding of Mohave Valley. The influx of Colorado River water and sediment at this time marks the inception of the modern Colorado River.

Tens to possibly hundreds of meters of river sand and gravel were deposited in Mohave Valley and elsewhere in the lower Colorado River trough in the subsequent 1- to 1.5 million years, as a tremendous volume of river sediment accumulated in the Salton trough. This massive aggradation probably resulted from rapid erosion in the Grand Canyon as the Colorado River downcut through that region.

The studies mentioned above have created a new problem for geologists. What are we supposed to make of the marine and estuarine organisms in the Bouse Formation? These organisms require salty water, but have been found only in sediments of the southernmost of the basins in which the Bouse Formation was deposited (the large Blythe sub-basin). Recent calculations show that evaporation in the southernmost lake as it was filling with river water could have elevated salinity to sea-water levels. The organisms, however, would have to be carried from the sea to the lake and delivered in sufficient numbers to provide a reproducing population. This seems like an impossible task, but long distance transport of aquatic organisms by birds has been documented in a number of places.

In conclusion, the abrupt arrival of the Colorado River to the low western desert region as a series of lakes roughly coincides with the beginning of incision of the Grand Canyon. Before this time,

water that flowed off of the west slope of the Rocky Mountains and into the interior of the Colorado Plateau must have terminated in a lake on the Plateau or exited the Plateau along an unknown route. We think it most likely that cutting of the modern Grand Canyon began with spillover of a very large lake in northeastern Arizona and rapid incision of the lake outflow point about 5.5 million years ago. Details of the spillover and development of the Colorado River through Grand Canyon are not known, but we suspect that it involved catastrophic flooding and rapid erosion. As the Colorado River propagated downstream through the Basin and Range province, it sequentially filled, spilled over, and drained a series of formerly closed basins, eventually linking with the Gulf of California by 5.3 million years ago.

But, the Colorado River has not always been free flowing to the Gulf of California. Volcanic flows have dammed the river several times in the last 1 million years.

For a broader view of Arizona geological history, see my seven-part series (links in Article Index).

Hurricanes and Oil Slicks

In true Mencken style (“The whole aim of practical politics is to keep the populace alarmed by menacing it with an endless series of hobgoblins, all of them imaginary.” ) an AP story on the front page of the Arizona Daily Star speculates on dire consequences that may occur if a hurricane meets the oil slick in the Gulf of Mexico.

Here is what the National Oceanic and Atmospheric Administration (NOAA) says about such a possibility:

Most hurricanes span an enormous area of the ocean (200-300 miles) — far wider than the current size of the spill. If the slick remains small in comparison to a typical hurricane’s general environment and size, the anticipated impact on the hurricane would be minimal. The oil is not expected to appreciably affect either the intensity or the track of a fully developed tropical storm or hurricane. The oil slick would have little effect on the storm surge or near-shore wave heights.

The high winds and seas will mix and “weather” the oil which can help accelerate the biodegradation process. The high winds may distribute oil over a wider area, but it is difficult to model exactly where the oil may be transported. Movement of oil would depend greatly on the track of the hurricane. Storms’ surges may carry oil into the coastline and inland as far as the surge reaches. Debris resulting from the hurricane may be contaminated by oil from the Deepwater Horizon incident, but also from other oil releases that may occur during the storm. A hurricane’s winds rotate counter-clockwise. Thus, in very general terms: A hurricane passing to the west of the oil slick could drive oil to the coast. A hurricane passing to the east of the slick could drive the oil away from the coast. However, the details of the evolution of the storm, the track, the wind speed, the size, the forward motion and the intensity are all unknowns at this point and may alter this general statement.

Evaporation from the sea surface fuels tropical storms and hurricanes. Over relatively calm water (such as for a developing tropical depression or disturbance), in theory, an oil slick could suppress evaporation if the layer is thick enough, by not allowing contact of the water to the air. With less evaporation one might assume there would be less moisture available to fuel the hurricane and thus reduce its strength. However, except for immediately near the source, the slick is very patchy. At moderate wind speeds, such as those found in approaching tropical storms and hurricanes, a thin layer of oil such as is the case with the current slick (except in very limited areas near the well) would likely break into pools on the surface or mix as drops in the upper layers of the ocean. (The heaviest surface slicks, however, could re-coalesce at the surface after the storm passes.) This would allow much of the water to remain in touch with the overlying air and greatly reduce any effect the oil may have on evaporation. Therefore, the oil slick is not likely to have a significant impact on the hurricane.

All of the sampling to date shows that except near the leaking well, the subsurface dispersed oil is in parts per million levels or less. The hurricane will mix the waters of the Gulf and disperse the oil even further.

The experience from hurricanes Katrina and Rita (2005) was that oil released during the storms became very widely dispersed.

Besides NOAA, other sources say that storms disperse and/or bury oil already on the beach. Tar balls are common on Galveston Island beaches but less so after a storm. The Marshes should fare the same way. If anything, hurricanes have a tendency to leave beaches cleaner than they found them.