Waterjetting 2c - using Nature's crack system

In this section (part 2) of the series on Waterjetting, the focus is on the way in which high-pressure waterjets grow cracks in their target. As John Field showed, even the presence of microscopic cracks on a glass surface are enough to initiate the larger cracks that lead to failure. In many cases, however, the most useful growth can be achieved if the cracks only extend to the point that they remove a desired amount of material. This becomes important where there are weaknesses and flaws in the material – such as the layers between plies of wood, or even Kevlar - which should not be grown as the jet cuts down through the material. And in a later article this topic will be a part of a discussion as exactly what happens as a jet drills a hole into a target. But, for today, I would like to talk about crack growths in rock and soil, both because it is one of the oldest ways in which water can penetrate into material, and also because it holds the potential to be one of the newest areas into which waterjetting is growing, and will likely further advance into a more significant business.

And to begin consider that, as water penetrates into the cracks in a rock, and grows those cracks slowly, under natural forces, rocks with minerals in them, will see those mineral particles separately broken out. The classic example of this is with gold. One of the ways in which the Forty-Niners found the gold in California was by panning for the gold particles in the rivers, and tracking the gold deposits back up-stream until they reached the original gold deposits of the Sierra Mountains. Not that this was the first time that water transport had helped in gold mining. One of my favorite stories to begin classes is to remind them of Jason and the Argonauts.

Figure 1. Movie poster for the 1963 film version of Jason and the Argonauts (iMDb )

It is a theme that has been made into a movie several times, (see, for example, here) and tells the story of how the Greek Prince Jason and a band of companions go in search of the Golden Fleece, and the adventures that he has along the way. Despite the mythical creatures the story is thought to be likely based on some measure of truth, with the voyage taking place some time before 1300 B.C. But our focus is on the fleece, rather than the voyagers.

Figure 2. Suggested path that Jason followed to get to the River Rhion in Georgia.(Google Earth)

Within the Caususus mountains of Georgia lies the modern town of Mestia, which was thought in Roman times, to be the site of Colchis, where Jason found the Golden Fleece. The reality is not quite as dramatic as the legend since, as the Roman historian Strabo noted

“It is said that in the country of Colchis, gold is carried down by mountain torrents, and that the barbarians obtain it by means of perforated troughs and fleecy skins, and that this is the origin of the myth of the Golden Fleece”

The torrents of water in the Svaneti valley outside Mestia, (Nika Shmeleva Google Earth at 43deg02’29.74”N, 42deg42’25.13E)

It is thought that the miners of the time directed the streams so that they flowed over the veins of gold and eroded out the particles so that the gold was carried down to the valley. Here it was fed through the troughs that Strabo described, and the heavy gold particles were captured as they tangled in the wool of the fleece. To recover the gold the miners would then hang the fleeces in trees, so that they would dry, and the gold could be shaken loose. Unfortunately as the fleeces hung in the trees they provided a tempting target for Greek thieves. (In a later version that I will write about in the next post the sheep fleece was replaced with brush that could be dried and burned to release the gold).

Water was thus, in one of the earliest “automated” mining processes, used to both dislodge and then carry the valuable mineral from the mining site The overall power of water to move soil has been used to wash away material for over a hundred years. In the 1973 War between Egypt and Israel the Egyptian Army gained a significant advantage in the early hours of the war by using waterjet monitors to wash away the defensive barrier along the edges of the Suez Canal, rather than using conventional mechanical excavators.

To deal with the massive earthen ramparts, the Egyptians used water cannons fashioned from hoses attached to dredging pumps in the canal. Other methods involving explosives, artillery, and bulldozers were too costly in time and required nearly ideal working conditions. For example, sixty men, 600 pounds of explosives, and one bulldozer required five to six hours, uninterrupted by Israeli fire, to clear 1,500 cubic meters of sand.

The quoted Sunday Times report of the time suggested that the Israeli Army had anticipated that it would take 24-hours to remove the barriers giving time for their Army to mobilize and arrive. However, using a set of five pumps per breech site the Egyptian Army was able to make an opening in as short as a 2-hour time, with the mobilized water cannon opening 81 breeches, and removing 106 million cubic feet of material in that first day of the war. They were thus able to initially advance into the Sinai with relatively little resistance.

The pressure of the water does not have to be high to disaggregate the soil, but large volumes were needed in that application both to break the soil loose and to move it out of the way. Moving the debris out of the way is an important part of the operation, and while, in the above case it could be just pushed to one side, in many more localized jobs, particularly in cities, that is not an answer. However if the soil can be collected with the water, then the fluid can help to move the soil down a pipe away from the working area. And, more importantly, if the soil can be captured as it is being broken loose, then both can be collected before the water has had a chance to penetrate into the soil around the hole, and so the walls of the hole will not get wet, and will remain stable and not fall in.

One way that we have achieved this is to rotate a pair of waterjets relatively rapidly (depending on the material the jet pressure can range from 2,000 psi to 10,000 psi) so that the surface layer is removed, and to immediately take this away by combining the jet action with a vacuum for removal. (In the initial trials we used a Shop Vac to remove both water and debris). This combination has become known as hydro-excavation, and will be the topic of a couple of posts in the future.

Similarly the use of high pressure to break an ore down into its different parts, so that the valuable mineral can be separated from the host rock at the mining machine, is become a new way to reduce the costs of transporting and processing the ore, and make mining more efficient. As yet this latter is still more of a laboratory development, though it will develop for greater use in the future, and there will be additional posts on this too in the future. But, in both cases, the use of waterjets to effectively rely on extending pre-existing cracks makes the systems work. In the next post I’ll write about a couple of other ways of getting enough cracks into the rock as ways of making it easier to separate and remove valuable materials from underground.

OGPSS - Oil production from the North Caucasus

When the topic of Peak Oil is raised, one of the first responses that is often heard from those trying to explain why a peak isn’t going to happen, at least in the short term, is that technology will come up with new answers. These will allow greater production of oil through access to previously unavailable reservoirs, and an increase in the amount of oil that can be economically recovered from them. It is an argument that has had demonstrable success in the past. An earlier post showed that innovations in technology allowed the region around Baku in Azerbaijan to remain one of the centers of oil production since the time of the first Russian oil pipeline in 1878 through today. The statement is, unfortunately, not universally or ultimately true, but it does provide an introduction to today's topic.

The change from cable-tool drilling to rotary drilling resurrected production in the Caucasus after the Soviet Revolution, and the growth of production to include the areas of the North Caucasus also brought other fields on line. These were initially the fields around Grozny and Maykop and in combination they raised production to around 622 kbd at the start of the Second World War. In more recent times it has been, again, the introduction of the latest Western technology that has helped sustain Azeri production, and new technology is starting to improve and sustain production in the North Caucasus.

The countries, and some key locations, in the North Caucasus (after a map from the BBC News )

Georgia, through the port at Batoum (now Batumi), was one of the early exporters of oil from Russia to Europe.

The production of the northern Caucasus increased from 100,000 poods in 1877 to 1,656,000 poods in 1889. In the latter year Terek furnished 275,731 poods, Elisabetpol 3,000 poods, and Daghestan 3,955 poods, while in the Signakh field, near Tiflia, 55,296 ppods were obtained.

Note: poods were the early Russian measure of production and that there are 8.33 poods per barrel.

In the period from 1884 to 1914 Georgia exported a total of around 165 million barrels of oil of oil. This oil increasingly came from the fields around Grozny (now in Chechnya, Russia) and later from the fields around Maykop (now in the Republic of Adygea in Russia), even though there were considerable signs of oil in Georgia (oil sands near Signakh west of Tbilisi and gilsonite in the Guria district). The Grozny fields were producing about 18% of Russian oil (with the rest coming from Baku) in 1915.

Following the collapse of oil production with the Revolution and the end of Western ownership, it was the use of rotary bits that allowed production to ramp back up, supplying a seventh of Western European imports (John Grace – Russian Oil Supply), and providing needed income to the Kremlin.

During the Second World War the region became a target for German occupation, given that oil from the region was providing a third of German imports in 1940. (Daniel Yergin – The Prize) However although Operation Blau reached Maykop, the smallest of the three main oil concentrations, the oil fields had been destroyed, so that only around 70 barrels per day were left available. The German Army soon became bogged down in the siege of Stalingrad, to the North, and did not reach Baku.

The oilfields around Grozny were first developed in 1893, with 386 wells by 1917 and grew steadily. The Grozny field peaked at around 154 kbd in 1932, while the output from the entire Chechen-Ingushettia region, which fed to the three refineries at Grozny, fell to around 148 kbd by 1980 and to106 kbd by 1985. Grozny then became more of a pipeline terminal.

The first major pipeline, running from Grozny to the refinery at the port of Tuapse had been built in 1927. The pipeline was later extended to also pick up oil from the Maykop fields, and fell into disuse in 1968 when it was replaced with more modern pipelines to the rail terminals and oil terminal at Tikhoretsk, and that pipeline is now being increased in size to carry 250 kbd of oil. Overall the terminal which takes oil from the North Caucasus and Kazakhstan and forwards it to Novorossiysk, on the Black Sea, has a maximum throughput of 640 kbd. Part of the pipeline carried oil initially from Grozny to Baku, but with the onset of the Azeri-Chirag-Guneshli project flow is now reversed.

Grozny has had an unfortunate history with the surface structures being largely destroyed, first in the Revolution, and then by German bombers. The town and facilities were rebuilt and became the center of the local oil business. The Chechen wars of 1994-96 and 1999-2000 then largely destroyed the center of the city. Similarly the oil wells in the region were impacted, in the 1994 war only 100 wells, out of 1,500, were operating by the turn of the year.

The more recent finds, that are resurrecting the promise of the North Caucasus come, however, as do many recent discoveries, offshore. Lukoil carried out a series of explorations in the North Caspian between 1999 and 2005, finding six large fields off the Dagestan and Kalmykian coasts. These were Khvalynskoye, Yuri Korchagin (50 kbd) , Rakushechnoye, Samatskoye and Filanovsky. The fields were initially assessed at around 4.7 billion barrels of oil, with the Valdimir Filanovsky being claimed as the largest new oil reserve discovered in Russia in 20 years. The initial well flowed at 6,400 bd with reserves estimated at 600 million barrels, with 34 billion cu. m. of natural gas. Overall North Caspian production was anticipated to peak in 2013 at 170 kbd, but Filanovsky alone, due on line in 2014, is now anticipated to reach 210 kbd with production initially coming from 11 directional wells with horizontal completions. To reach these levels Lukoil will be investing some $22 billion.

Location of the Korchagin field (Lukoil )

Looking further into the future Lukoil are expecting to be able to further develop the North Caspian to reach a production capacity of 320 kbd of oil and 13 billion cu m of natural gas per year, by 2020. Lukoil expects that the increase in production will be able to offset declines that are anticipated from Western Siberia by that time.

The introduction of modern technology is thus helping to increase production from regions that were, at one time, thought to be exhausted. It should, however, be remembered that horizontal wells have now been around for some 30 years. One wonders what ,so far unpublished, new technologies will appear to help within the decade, since to have an impact they must be widely accepted and adopted, and I don’t hear of much.

Design of the Filanovsky platform (CNGS Group )

Saturday Pick Points

There were only a couple of entries over in Real Climate this week, and they seem to be becoming more remarkable for their defensive nature. But it has been that sort of a week. It really began over at Climate Audit following up on the paper that I mentioned a couple of weeks ago, in which Eric Steig et al wrote about a change in the calculations on Antarctic temperatures, resulting in a greater warming than had been projected in earlier evaluations.

So Steve McIntyre has a look at the data that was used for that re-evaluation, and focused in on data from one of the Automated Weather Stations (AWS) called Harry, which had shown the greatest trend in data. And he found that some of the data that had been originally reported for Harry, instead belonged to a station called Gill.

Writing this up at his site he noticed that the data at the British Antarctic Survey (BAS) was in the process of being corrected. It turns out that it was being corrected because Gavin Schmidt, who writes for Real Climate, had contacted them about the error, though that did not become clear until February 4th. On which day Gavin wrote the somewhat defensive post at Real Climate, sensibly saying that by correlating manned station data with that from satellites and the AWS it had been possible to extend the estimates of actual temperatures, and that within the context of the process that was used, the erroneous data from Harry, and a third station known as Racer Rock, really didn’t make any difference to the results. (Incidentally Gavin’s actions drew a rebuke at Science Policy ).

In the process he admitted that the data from the AWS could be flawed, since the stations were, on occasion buried in the snow. (see photos at the Harry website above). Which was a timely comment, given that Anthony Watts was just posting photos that showed some of the problems in acquiring temperature data in the Antarctic. And Climate Audit being the site that it is, on the 6th the new data was reviewed to see what it changed. The results (bear in mind that there are only a few stations in the area) show that it may not have been as inconsequential as stated.

And so we leave CA for another week, just as another controversy is starting , Steve draws attention to a letter by Michael Mann which is, sadly, another demonstration of how easily the AGW group slip into ad hominem attacks rather than debate the science.. The issue this time is an article by Lawrence Solomon, and it is another take on the Antarctic discussion. It points out that when the data shows that one thing is happening (Antarctic cooling) and you would prefer that it not, you can use statistics to show that the opposite (Antarctic warming) is occurring. He also takes a dig at the “hockey stick” and that is the cause of Dr. Mann’s ire. The controversy is likely to go on into next week, and the latest response is from Mr. Solomon.

That whole relationship between Climate Audit and Real Climate looks to continue to be adversarial, since the new paper that is discussed at RC today has met with a rejoinder at CA suggesting that the data in the paper gives a different conclusion to that drawn.

Well, other than that WUWT points to a post where the new Secretary of Energy is predicting the end of agriculture in California, and has more pictures of inappropriate siting of weather stations, while promising a comment on fossil fuels in the near future.

Gristmill points to a new site on coal that will be interesting to follow. There is also a move to get to 25% renewable energy by 2025, as well as a lead to an initiative in Georgia to restrict coal use. And EPA is starting to work on the new sets of rules that will apply to coal-fired power stations.

Well these stories have kept me fascinated all day (the Antarctic ones) so I am going to stop before I get too far into the backstory . . and off to get back to Peak Oil for the week.