Sunday, June 29, 2014

Tech Talk - the numbers keep going down

One problem with defining a peak in global oil production is that it is only really evident some time after the event, when one can look in the rearview mirror and see the transition from a growing oil supply to one that is now declining. Before that relatively absolute point, there will likely come a time when global supply can no longer match the global demand for oil that exists at that price. We are beginning to approach the latter of these two conditions, with the former being increasingly probable in the non-too distant future. Rising prices continually change this latter condition, and may initially disguise the arrival of the peak, but it is becoming inevitable.

Over the past two years there has been a steady growth in demand, which OPEC expects to continue at around the 1 mbd range, as has been the recent pattern. The challenge, on a global scale, has been to identify where the matching growth in supply will come from, given the declining production from older oilfields and the decline rate of most of the horizontal fracked wells in shale.

Figure 1. Growth in global demand for oil (OPEC MOMR )

At present the United States is sitting with folk being relatively complacent, anticipating that global oil supplies will remain sufficient, and that the availability of enough oil in the global market to supply that reducing volume of oil that the US cannot produce for itself will continue to exist.

Increasingly over the next couple of years this is going to turn out to have created a false sense of security, and led to decisions on energy that will not easily be reversed. Consider that the Canadians have now decided to built their Pipeline to the Pacific. The Northern Gateway pipeline that Enbridge will build from the oil sands to the port of Kitimat.

Figure 2. Route for the Northern Gateway pipeline (Northern Gateway )

The 731 mile long pipeline will carry 525 kbd to the port, and a twin pipe will carry some 193 kbd of condensate back to Bruderheim to help in the processing of the initial crude. It will, sensibly, move the oil that was to have come down through the Keystone pipeline to American refineries instead to tankers out to the Canadian coast, where it will be shipped to Asia to meet their growing demands. Given the investment in the pipe, infrastructure etc once this oil is committed to that market and the US will not be able to gain that supply back when it is needed in a few years.

There is a secondary impact to the opening of that market that may not be evident for a little time, but it something that the Russians discovered after the gas pipeline connected Turkmenistan to China. Suddenly there is a second market for the product, and producers are no longer tied to having to accept the price that the sole purchaser is willing to pay. At the moment, when there is a sufficiency of oil, that is an incidental, with significant impact only in improving the economics of the oil sand operations, but since it now ties the American refineries that would have received this oil more closely to the Venezuelan production it now receives (a somewhat less reliable supplier) this change remains as something of a future concern. It is not likely, in itself, to initially change the price of oil much ( a minor increase) but it will change the names and nationalities of those that profit from the trade.

The problems that the Keystone pipeline had are, to a degree, a function of the lack of concern over the supply of oil to the American market. As long as oil production continues to increase, from the Bakken and Three Forks in North Dakota, and the Eagle Ford in Texas, then there is no clear evidence for concern. But those wells are cumulatively starting to reach peak production, and the next shales on the list (the Spearfish and the Tyler) don’t hold the potential to match the gains that have been achieved to date. Particularly this is when, as the North Dakota DMR notes, the wells see an average decline of 65% in the first year.

Figure 3. Typical Oil production from a well in the Bakken:Three Forks region of North Dakota (ND DMR Oil and Gas Division )

The projections that gains in production continue thus rely on a continued high level of drilling and production with a defined rig count required having been estimated, and an assumed sustained level of production even beyond the time that the “sweet spots” start to disappear.

Figure 4. Projected production from the Bakken:Three Forks formations, assuming well productions are sustained and that the rigs are available. (ND DMR Oil and Gas Division )

At the end of June, 2014 the rig count in North Dakota is less than 190 (DNR says 189, but Kirk Eggleston notes that some 15 of these are moving, so that the real number is 173, a bit less than 225. That suggests that peak production may be delayed, and lowered from 1.75 mbd down to around 1.4 mbd. This reduction in short-term supply will have less impact in the US than elsewhere since it will be used to release oil that the US would otherwise have bought to the world market, but less than anticipated, and at a slower rate than expected. (Note that Eagle Ford production growth rate is also slowing and that this also affects OPEC projections which anticipates that US oil production will grow some 950 kbd this year).

At the same time, as I have noted in an earlier piece the reliance of many models of future oil supply have focused on Iraq as the next major supplier to sustain growth in production, even as other suppliers decline. But those projections are increasingly obsolete. It is unrealistic to expect the oil export business from Iraq to be sustained and continue to grow in the face of the developing civil war. The nature of the conflict makes it difficult to see how it can be easily resolved, and particularly if the country becomes divided, then the oil pipelines become a target of opportunity to attack the financial underpinnings of the different sectors. It is likely that the pipeline from Kurdistan into Turkey will carry increasing volumes up to Ceyhan and thence to the world market, under better security, given that does not now venture into Sunni territory, but the vulnerabilities likely remain.

The result of these declines in anticipated production (not to mention Libya, the Sudan’s etc) is likely to become evident within a year, while demand continues to grow. The balance need change only a small amount however, for the consequences to be dire. As Mr. Micawber said in “David Copperfield”:
Annual income twenty pounds, annual expenditure nineteen [pounds] nineteen [shillings] and six [pence], result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery.

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Saturday, June 28, 2014

Waterjetting 22d - more on shrouds

The use of a shroud to capture the water and debris from waterjet use, feeding it to an exhaust hose, that will then carry it away from the site, has become more universally applied over the last ten years.

There are, however, different ways in which this new combination (which has been given different names depending on the usage) can be applied, and how the components can be best combined for most effective application.

At the low end of the pressure range, feeding a 2,000 psi waterjet at 2 gpm into the soil at the entrance to a suction hose has created a powerful new tool for deep soil excavation. The technique, known as hydro-excavation, has a variety of different applications – one of the simpler demonstrations was shown by Hydro Spy here on Youtube.

The demonstration lasts some five minutes, and helps show why there is still improvement needed in equipment design, since the vacuum intake is not extracting material at a constant rate, but is only being fed by a hand-held lance that it often not cutting very efficiently, while at the same time the head is either buried in debris or being held too high off the surface to effectively capture the loose material effectively.

Figure 1. Components of a hydro-excavation system, the jet is breaking the soil into pieces that are they removed from the hole with the water, through the suction line. (Hydro Spy )

Because the two actions (jet fragmentation and vacuum removal) are separate they are both working at much less efficiency than if the situation were modified. For example, in the video, the lance is used to pry pieces of soil from the wall and too much time is spent with the lance away from the suction line or with the intake to the line buried and not removing material.

Figure 2. Frame from video showing lance being used to pry soil block from the solid – the suction line is not getting any water or soil at this time.

It is often forgotten that, in soils, the jet penetrates to maximum depth in about one hundredth of a second. Thus, to be effective it has to be moved over the surface relatively fast ( as it is in parts of the video) in order to be most efficient. This is, however, most often best achieved by driving the head mechanically, rather than relying on an operator to move the nozzle as fast as it should be moved. In a simple situation such as this it may be, for example, much more effective to use a dual-jet self-rotating nozzle assembly (which can be obtained from one of several equipment manufacturers) since these designs spin the jets over the surface more rapidly and consistently, so that the material is more effectively broken into relatively small pieces.

However in this section we have been discussing the use of shrouds and intakes to the suction line, and this design becomes of equal importance in ensuring that the system works at its most efficient. If the entry to the suction line in blocked because it has been run up against the bottom of the hole, or into a tight cluster of large pieces of material, then there is no production, until the head is lifted away from that seal. (Or if a short rod is attached to the bottom of the inlet to ensure that there is always a gap between the lip of the line and the bottom of the hole).

On the other hand if the inlet is lifted too far away from the surface, say more than half-an-inch, then the suction force pulling the pieces into the line becomes significantly less effective and production will again suffer. This is made worse where the floor of the opening is very uneven, since this makes it more difficult to maintain the gap at which the suction is most effective.

It becomes more effective – whether removing soil in this way or removing paint from a ship hull at much higher pressures – to integrate the jet action with the design of the shroud/inlet to the suction line. The two cases are otherwise different in that in the softer material the jets are cutting quite deeply (though hopefully no more than about half-an-inch at a time) into the soil, which causes the jet to rebound back up into the shroud body and makes water and debris collection relatively easy.

This is not the case with the removal of paint and coatings, where the layers are often relatively thin, and the jet will rebound, often parallel with the underlying steel that it does not have the power to penetrate. (Nor is this desirable, other than for the jet to penetrate into any corrosion pits in the surface and clean them).

With thin coating removal, since the surface is otherwise relatively smooth, the shroud can be mounted on wheels that allow the operator to set the gap thickness between the shroud and the surface. (The closer the shroud lip to the surface, the higher the force that holds the shroud to that surface, but also the higher the force that the motors must apply to move the shroud against the friction forces that are created). The suction force in this case will hold the shroud against vertical walls and even against the underside of ships hulls, bridge decks, etc. provided that the geometry of the head is optimized to provide that balance of enough suction to hold the head, without it getting too high for the trouble the traversing motors).

There is one other, final thought, in those cases where the jets are cutting into and along paint and other coatings. In some cases the coating can be best removed where the jet is attacking along the surface, rather than almost perpendicular to it, as is quite often the case in head designs. This can give a better and more efficient surface cleaning, but if the jets are at too great an angle to the surface, the operator runs the risk of seeing the jets carry the debris out past the edge of the shroud, making it much more difficult to capture and remove.

One way of getting around this problem is to incline the jet path within the shroud, so that at the distant end of the jet path within the shroud it intersects the path of the next jet around the design, which has sufficient force to stop the jet moving further out. We have successfully demonstrated that this does work in an application, where the jet was cutting relatively shallow grooves in the surface, and with greater penetration the jet will rebound upwards out of the slot, and more easily captured by the overlying shroud.

Figure 3. Showing how, by aiming the jet path into that of the next stream around the shroud the energy of the jets can be contained within the shroud envelope and the splashing outside of that envelope is much reduced.

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Sunday, June 22, 2014

Tech Talk - More on Iraq

A single picture is sufficient to tell the story of the fate of the Baiji Refinery in Iraq. Recently reached by the ISIS forces, it has been the largest refinery in Iraq, with a capacity of 310 kbd, and has been used to provide products for domestic use. Since it would provide fuel for both sides in the conflict it had been left largely intact, but that “understanding” seems to have fallen apart.

Figure 1. View from space of the fire at the Baiji Refinery in Iraq (Slate)

The remaining significant refineries in Iraq are at Daura near Baghdad which can produce 210 kbd, although promised at 280 kbd and Basra in the south, which can produce 140 kbd. There are an additional 11 very small refineries located around the country.

The conflict has already led to a drop in Iraqi exports of around 300 kbd and while this will not immediately impact the United States, given that imports have been declining in the face of growing domestic production, it will affect the overall global market, with longer term impacts on price and availability. India, for example, is already worried. It is quite possible that Iraq will partition, with the northern tier ending up Kurdish.

Figure 2. The Kurdish part of Iraq (Talking Points Memo)

This region has already run a separate pipeline through its own territory up into Turkey and thence to Ceyhan. From there it is tankered, and the Kurds have just sold a shipment to Israel, which arrived at Ashkelon on Friday and unloaded that night. The report has, however, been denied by the Kurdish Ministry. Three more tanker-loads destined for other customers are now in process at Ceyhan. The tanker was one which has, until recently, been unable to find a market.
In May, the Kurds took a further step by leasing two tankers, loading them in Jihan and looking for buyers. Attempts to sell oil to Morocco and other countries were rebuffed, out of solidarity with Iraq and concerns over legal action. It now seems that the Kurds have re-discovered their old ally Israel, which agreed to purchase the oil. To avoid a direct sale, the Kurdish tanker unloaded its oil onto another tanker. It’s unclear if the purchase is a one-off deal or the start of a permanent arrangement.
But the Kurdish pipeline is currently limited to a capacity of 100 kbd, whereas the main pipeline running up the center of the country (and through ISIS territory and control) can handle 600 kbd. The potential for a continued drop in Iraqi exports flowing north to Turkey of over 500 kbd is thus now quite possible. However the oilfields in the Kurdish territory are only, at present, producing around 120 kbd. Yet, by the end of the year it is projected that the pipeline can be expanded to handle flows of up to 400 kbd, with that capacity being reached as additional oilfields around Kirkuk are connected into the system and production raised. In the meantime additional oil is being trucked up to Turkey.

The impact of the conflict has already caused bidding on the Nassiriya oilfield and refinery to be postponed indefinitely.

Figure 3. Location of Nassiriya (Red point) (Google Maps)

Bidding on development of the 4 billion barrel oilfield, and associated 300 kbd refinery, was scheduled to have taken place on Thursday, but after being postponed in December and January has now been put off indefinitely.

At the same time Lukoil remains optimistic about expanding the West Qurna 2 field over the next year. The field has started production, and reached 200 kbd and Lukoil is hoping to start filling tankers in the third quarter of this year. The project was shared with Statoil, but they dropped out in 2012. West Qurna is in the South of Iraq, and at present a considerable distance from conflict.

Figure 4. The location of the West Qurna 2 field. (Statoil)

The field is anticipated to ultimately be capable of yielding 1.8 mbd of oil. In order to handle higher flow rates a new agreement has just been signed in which Lukoil will build two new pipelines from the field down to the off-shore terminal at Fao.

As long as the conflict remains north of Baghdad, and the oilfields in the South are not threatened then the major restriction on plans to grow exports from the south to 6 mbd may continue to lie with the Iraqi bureaucracy and the delays in installing the necessary infrastructure needed to support both production and also transport of the oil to the offshore terminals. There has also been some reduction in targets, for example Zubair which had been producing at 200 kbd was originally scheduled to produce at 1.2 mbd a target that was dropped to 850 kbd last year. A 200 kbd gas and oil separation plant (GOSP) has just been contracted, with completion in 2016.

This does not discount, however, that sabotage and terrorist attacks will not have some impact. The main pipeline to Turkey has been closed for months due to such attacks, but while that pipeline runs through Sunni territory, the lines from the Southern fields are all within Shia controlled land, and those in the north are now controlled by the Kurds. Oil companies have, however, as a precaution, begun repatriating some of their employees. Gazprom has just begun production from the Badra field. Originally projected to begin, at 15 kbd, in 2013. Production has now begun, although it is now anticipated that it will be another couple of months before the field reaches that initial 15 kbd target, and 2017 before it peaks at 170 kbd. Gazprom have, at least publically, “no problems” at the site.

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Saturday, June 21, 2014

Waterjetting 22c - More on shroud design

Lowering the pressure in a hose connected to a cutting head, by connecting it to a vacuum pump, will pull a certain amount of the water and debris released from a cutting/cleaning event into that hose. However to ensure that all of this material is captured, rather than just a fraction, requires a little more care and effort in the system design.

At the end of the last post on this subject, I began discussion of the use of shrouds to help to contain the ejecta and to direct it towards the suction line.

Figure 1. Schematic section through a shroud of a device, designed to mine high-level radioactive waste.

There are a number of different lessons that we learned as we developed this tool, and this piece will discuss a number of them. During the development and demonstration of the device we had to use a simulant, and a relatively weak cement was chosen, which would allow us to design the tool to operate it where we could see it, and easily interact with it.

Figure 2. Cutting test under way (no shrouds were used in this early test series)

The easiest way to drive the nozzle system was to run the high pressure tubing through a fixture that contained a hollow shaft electrical motor. This saved a lot of space, and allowed the high pressure tubing to feed into a distribution manifold under the motor, which fed the high-pressure water to a set of rotating nozzles.

Figure 3. Test rig without jets to show the design of the test head.

In figure 2 the jets issue from two self-rotating nozzle sets, themselves fed through a rotating feed tube, itself rotating around a central axis, and driven through a belt drive and gearing.

Various different patterns were cut into the simulant, as the different heads were moved over the surface, with the pattern controlled by the different rotation speeds relative to the overall head speed over the surface.

Figure 4. Computer image of the jet paths over the surface, in one combination of parameters for a head similar to that shown in Figure 3.

The design of the head was aimed at producing a set of jet passes (given that each jet was slightly inclined to the surface) which would produce pieces of simulant that were never larger than half-an-inch in size. Yet at the same time the goal was to remove 4 cu. ft. of waste each minute. The larger we could break out the particles, the less cutting we would have to make into the waste itself, saving energy and time, while at the same time increasing the overall volume we could release in that time.

Figure 5. Deeper cut into the simulant.

At the same time if the cut depth was too great, then several new problems would arise, apart from the initially obvious one of producing particles that would be bigger than the suction hose could easily handle. (Though we overcame that hurdle by running the particles through a high-pressure jet pump that effectively cut any oversize particles down to an acceptable size as part of its design).

The suction line needed more than just the water from the cut, to be able to pick up all the debris from the cutting operation. Air had to be drawn in around the sides of the shroud, yet at the same time the walls of the shroud had to come down to restrict the amount of that air and keep the suction strong enough at the surface to remove all loose material. This is done by fitting a rim of bristles (such as form the head of a paint brush) around the edge of the shroud that come down to brush over the outer edge of the cut, stopping a lot of the material from escaping out from the edge, while limiting the amount of air that feeds into the shroud, and in this way holding the suction pressure inside the shroud.

Figure 6. Early test showing a square shroud with bristles around the edge as it cuts into the waste. (Part of a previous pass has been filled with clay as part of the test). The shroud was larger to ensure that all ejecta was captured – as shown.

During the tests we found that the metal rim should, optimally, be no more than half-an inch from the surface of the material, after it had been cut, to pull all the material from the bottom of the crevices. But the edge of the head has also to pass over the surface in successive passes. So that high points left by deep cutting (Figure 5) will catch on the head, and can interfere with the rotation of the head on the next pass.

The aim of the cutting head design was, therefore, to leave a relatively smooth surface (of the sort shown in figure 3) over the waste after each pass, so that the head could be fed automatically down a fixed amount without any risk of it catching on large peaks left by the previous cut. This risk could also be lowered a little by slightly tilting the head backwards as it moves over the surface, since this allows slightly larger points to enter the head, where they are attacked by the jets before the driving mechanism has to pass over them. This tilting also makes it easier for the head to clean right up to the walls of the tank, where otherwise the edge of the shroud would hit the wall and stop the jets from removing that last rind of material from the edge. (Though it could be cleaned by a subsequent pass with the head turned up parallel to the wall and moved over it in that way – though this wouldn’t capture all the material as easily, due to wall curvature.)

Tilting the jets at a high angle so as to cut material at the edge of the shroud was also a possible problem, since it made it easier for the water to escape from the edge of the shroud, and out into the main body of the tank, which was undesirable. But I’ll talk about that in a later piece. Let me just note that, when these factors were all combined no material escaped from the edge of the shroud.

Figure 7. Test late in development, where a head similar to that shown in figure 1 is cutting over waste, without any material being ejected from around the shroud edges.

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Monday, June 16, 2014

Tech Talk - Thatcher, Putin, Coal and Gas

Back some forty years odd years ago when Edward Heath was Prime Minister of the United Kingdom, and the coal industry was still nationalized, the miner’s union went on strike, just after the Christmas Season. This followed an overtime ban that had started the previous November. The strike began on January 9, 1972 and lasted 7 weeks. Tellingly, just after it began some 17 schools had to close, as they had no heat in their buildings, without coal. Within a month the Government had to declare a state of emergency, and factories began to close due to a lack of power. Sensibly the Government of the day gave in to miners’ demands and they went back to work at the end of February.

Two years later there was a relatively similar series of events, with an overtime ban, followed by a three-day workweek as power cuts and blackouts developed, but this time Edward Heath also called a General Election, assuming he had the national sympathy. He was wrong, he lost.

These lessons were not lost on Margaret Thatcher, who had noted that it was not smart to offend the miners when the nation still relied on coal for much of its power, and when, in the winter, there was not a lot of coal in reserve at the power stations (because of the preceding overtime bans leading into winter). Thus, in 1984 when she, in turn, had to face the wrath of the National Union of Mineworkers (NUM), she had made sure that the situation was much different. Prior to the strike she had arranged for coal stockpiles to be built up over a period of three years. In addition the strike began on March 5th. It started because of the Coal Board decision to close 20 mines (since the earlier strike the number of miners had already fallen from 250,000 to 187,000 and the closures would cut another 20,000 from that number). It crumbled a year later, with a vote to return to work on March 3, 1985. The mining industry never recovered, and by the turn of the century the NUM was down to around 5,000 members.

I was reminded of those days by the latest clash between Gazprom and the Ukrainian government. In the past, when the Russians demanded that Ukraine pay its gas bill, the timing usually took place at the beginning or in the heart of winter. The problem that this gave the Russians was that they were supplying Western Europe through Ukraine, and any shut-off in the supply of natural gas to Ukraine had immediate consequences in Europe, which has become increasingly dependant on that gas. The result of the timing of the disputes was, therefore, generation of considerable diplomatic pressure leading to a relatively rapid resolution, without Russia getting all the deals that it wanted.

This time, however, it may be that Russia has learned, as Margaret Thatcher did, that timing is critical in this type of situation. Instead of waiting to November to call in the bill, Gazprom has presented it in June, when European demand for natural gas is lower. In addition the Nord-Stream gas pipeline is in place. This carries roughly 2 trillion cu. ft. a year of natural gas 760 miles into Germany, without passing through Ukraine. The twin pipes were completed and on line by October 2012.

Figure 1. Nord-Stream (Baltic Sea pipeline) bypassing Ukraine with 55 billion cu m of natural gas a year, (Daily Mail), out of a total sale of 262 billion cu m.(Spiegel)Note a second major pipeline from Yamal goes through Poland.

And while there has been talk about bringing in natural gas through Nabucco, that has slowly faded in the face of reality. Gazprom (as Brenda Shaffer has noted) has done remarkably well in gaining control of the different feeds and pipelines that come out of the East and head west into Europe. For example:
Moscow has taken steps to block the entrance of Iran into European gas markets; in 2006, the Russian company Gazprom bought a pipeline from Iran to Armenia and limited its size to ensure that it could be not be used to carry Iranian gas into Europe.
Consistently supplies have been confined to pipes that are under Russian control. It has a percentage of the Interconnector that carries natural gas into the UK and there has been little regard paid as it stepped in and took interests in other national pipeline companies across Europe.

So Gazprom can now wait while Ukraine exhausts its own reserves. It is reported to have some 13.5 billion cu m on hand, but it needs to have 18-20 billion at the start of the winter, if it is to get through. By stopping the flow now, Russia is having Ukraine burn those reserves between now and winter, while keeping the nations further west supplied. This means that the pressure will become that much more intense on Ukraine as winter starts to approach, and there is no alternate source of supply.

Gazprom has not hesitated to profit from this in the past, and is already in a position to demand whatever price it sees fit.
Ukrainian and Russian officials have been fighting about gas pricing since Yanukovych was ousted. After Russia annexed the Crimean Peninsula, it hiked gas prices for Ukraine 81 percent, from $269 per 1,000 cubic meters of gas to $485. That price was the highest in Europe, and Ukrainian officials refused to pay, calling it politically-motivated retaliation.

Gazprom has since lowered its price demand to $385, broadly in line with prices for other European countries. Ukrainian officials have sought to pay less and have said the way Russia was structuring the deal meant they would remain vulnerable to price hikes if they did anything to displease the Kremlin.

“Any price they offer is in the form of a discount that can be undone at any time,” said Pierre Noel, an energy security expert at the International Institute for Strategic Studies.
Don’t hold your breath waiting for this to be resolved.

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Saturday, June 14, 2014

Waterjetting 22b - Steep seams and shrouds

It was not until we started to move the auger that I described last time, that I realized how heavy and cumbersome it remained. It is true that we could lighten it considerably (and we did in the UK version), but it was still largely a platform mounted device that was relatively easy to move on the surface, but which would be much more difficult to move around in the confined spaces underground.

In this regard it is worth comparing two photographs.

Figure 1. Coal being transported in the pipes at the Hansa hydraulic mine in Germany.

Notice in this first one how the coal is confined, there is no dust, and the tunnel is relatively clean and clear. Contrast this with the typical mining operation where the coal is carried from the working face to at least the main haulage drifts, and often all the way out of the mine using conveyor belts. (The method of transport that would also likely be used in a typical underground auger section).

Figure 2. Conventional belt conveyor carrying coal underground. (Famur )

Note that in the second photo the belt occupies most of the space in the roadway making passage more difficult, and that the coal is openly exposed. The problem that this occasionally generates is that the coal transfers from one belt to another as it moves through the mine by falling off the end of one belt onto the next. This puts dust into the air, and if not properly maintained coal dust can accumulate under the belt and around the support rollers and drives. If not cleaned this can create heat through friction, and can lead to disastrous fires.

Figure 3. Studying a belt fire underground (Office of Mine Safety and Health Research )

Confining the coal, and using the water that mined it as a transport fluid – or at least part of such – has many advantages.

The Russians were aware of this as they developed some of their different mining machines. One of these was a small monitor that could be pushed up a seam, from a lower drift (without the need of a higher one), by adding segments as the unit was jacked forward.

Figure 4. Russian GVD monitor

The monitor could be advanced up the seam, cutting a channel about 3-ft wide, and to the height of the coal. This relatively narrow channel confined the water and the coal produced, so that both ran back down to the drift, where they could be either enclosed in a pipe, or run into an open flume, that would carry the coal away. Once the drive had reached the end of the section, then the two hydraulic cylinders that sat under the monitor could be turned, so that, from a protected section down-slope, the monitor could successively ream out strips on either side of the entry, until the roof collapsed, or the operation holed through to the previous panel.

Figure 5. Schematic showing the sequence of extraction in a) a coal seam with a relatively strong roof b) a seam with a weak roof, where a pillar of coal is left between successive lifts, typically around 30 ft, so as to provide additional support to the roof as the coal is mined out.

Production from these machines averaged about 76 tons/hour from seams that were in the range from 2 to 4 ft thick, this was more than double the production output achieved by more conventional means, with significantly less manpower.

However while there are some conditions where gravity helps to bring the coal and water back together, there are many cases where this is not possible due to other constraints. This is where it becomes necessary to use a shroud to confine the jets, debris and water so that they can be extracted together, often using a vacuum to assist in the process.

Figure 6. Rendition of the combination of three cutting jets rotating around a vacuum tube to slice into material and remove it.

The particular device shown in Figure 6 was developed as a way of remotely slicing into high-level radioactive waste for the Pacific Northwest National Laboratory. The waste is held in underground storage tanks, where the levels are too high for human access. As a result the waste had to be broken into pieces and removed remotely.

The initial problem was that the tanks, though holding perhaps half-a-million gallons of waste, had only small (18-inches or less) ports through which they could be accessed. Thus a relatively small tool was required, yet the mining rate had to exceed 4-cu. ft/minute. The situation required an excavation system on the end of a robotically controlled arm. But the arm would have to be more than 60-ft long (in the end a cousin of the arm used on the Space Shuttle was used). Any mechanical force applied at the end of such an arm would have tremendous leverage on the holding fixture, and a relatively low overall force would have to be found, yet one capable of cutting material perhaps as strong as a weak cement.

The answer came in the form of the device shown in Figure 6. By placing three cutting jets to rotate around a central tube, connected to a vacuum line, one could cut into the material and break out relatively small pieces, which could be aspirated away with the cutting water. (The requirements were that there would be no water left in the tank for any significant amount of time). Because the bottom of the tank was some 40 or 50 ft below ground level a small, high-pressure (10,000 psi) jet pump was developed by Michael Mann, capable of drawing particles of up to an inch in size into the line, and then projecting them up with sufficient energy to carry them out of the tank.

Figure 7. Basic system conceived to mine high-level radioactive waste and remove it from a storage tank.

While this description of the system makes the tool seem to be relatively simple to build and operate there are a number of features to the design that are fairly critical in order for it to work well, and I will cover some of those next time.

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Tuesday, June 10, 2014

Tech Talk - Optimism is becoming harder to sustain

For some time the nations of OPEC have been suggesting that demand for their oil will remain relatively stable in the near future, as increased production from the non-OPEC nations is expected to more than meet demand increases. Thus, for example, in the May Monthly Oil Market Report OPEC anticipates that global oil demand will increase by 1.14 mbd this year, while non-OPEC production will increase by 1.38 mbd, allowing a slight reduction in the volumes OPEC market, which continues to fluctuate around 30 mbd. In the longer term, however, as previous annual oil company prognostications of future supply have emphasized, the MENA countries are going to be pulling an increased weight in supply. For example ExxonMobil has noted:
The Middle East is expected to have the largest absolute growth in liquids production over the Outlook period — an increase of more than 35 percent. This increase will be due to conventional oil developments in Iraq, as well as growth in NGLs and rising production of tight oil toward the latter half of the Outlook period.
At the same time BP pointed out that in just a couple of years demand for OPEC oil is likely to start to steadily increase.

Figure 1. BP view of the increased demands to be made on OPEC oil with time. (BP Energy Outlook 2035)

A large part of that increase has been expected to come from Iraq. With the end of the Iraq war, and the government encouraging development there were some claims that production might eventually rise to over 13 mbd (ahead of both Russia and Saudi Arabia). But those optimistic views had to be measured against the reality that the country has taken a long time to recover back to the 3 mbd levels of exports that it had achieved before conflict.

Figure 2. The fall and recovery of Iraq’s oil production. (EIA)

At present OPEC reports that Iraq was producing at 3.298 mbd in April, making it second only to Saudi Arabia (at 9.579 mbd) among the OPEC nations. There still seemed to be some chance that the country might be able to reach some lower target figures, such as those suggested in the OGJ.

Figure 3. Anticipated Iraqi exports and their market region (OGJ)

Regrettably violence is now significantly increasing in the country, with Mosul being over-run by Sunni militants. This puts them in charge of the main pipeline to Turkey, as well as giving them potential control of some of the adjacent oilfields.

Figure 3. Known Iraqi oilfields in 2010.

Euan Mearns has written of the potential for oil from the Kurdish regions and Turkey has just allowed a second tanker to sail from Ceyhan carrying oil from that region to the market, without Bagdad’s permission. The oil is being delivered through a new pipeline capable of carrying 100 kbd from Kurdistan into Turkey. The main pipeline (shown in Figure 3) can carry as much as 600 kbd and runs from Kirkuk and perilously close to Mosul. The new pipeline runs through Kurdish territory until it reaches Turkey.

The declining influence of the central government over the northern territories of Iraq does not bode well for future production gains. Conflicts are getting worse, and the country is approaching the point where it could well be partitioned, since the government forces seem unwilling to take on the insurgency. Violence has already spread to the Al-Bayji refinery some 130 miles north of the capital. This is the largest refinery in the country, and currently produces below its 300 kbd capacity, all of which is used for domestic consumption.

The problems that this reveals are unlikely to be resolved soon, it is much more likely that they will continue to escalate over the next months, if not years. The impact on Iraqi oil production should not be underestimated. While the oil in the Kurdish region can make its way through the smaller pipeline that is under Kurdish control, the greater flow rates needed to sustain future growth in supply cannot be met by that pipe.

In the South developments in the Mesopotamian region around Basra from the fields of Rumaila and Majnoon will likely continue, with production being shipped out from the new facility offshore, although this is already quite significantly behind schedule.

Figure 4. Oil fields of Southern Iraq (IEA )

One has only to look at the degrading situation in Libya, where production has fallen from 1.6 mbd to a current level of less than 200 kbd, with no path forward now evident for production levels to be restored. Those familiar with the region doubt that there will be much improvement in the situation this year, and if the country follows the Iraqi path (figure 1) then it is unlikely that the world will see significant Libyan production for this decade.

That loss of a million barrels a day is likely to become increasingly evident as world demand continues to grow at greater than that level each year. When this is combined with the increasingly inability of Iraq to increase production as it moves back into more vicious internal strife, then one has to ask from where can future gains in oil production be anticipated?

The major oil companies have urged complacency having bet on Iraq and OPEC coming through (and in the process assumed that Saudi Arabia would also increase production significantly above 10 mbd, something that they have consistently declined to commit to doing). As Libya and Iraq remove that surplus from the table then the question becomes where else can it come from?

It is increasingly unlikely that US increases in production can be sustained for long, given the very short high-level life of the new wells completed in shale, and as the sweet spots in the current fields are consumed. Thus within a couple of years we are now likely to see an increasingly desperate search for new reserves. But those reserves take years to find and develop (as well as large amounts of money), and if the crisis comes at a faster pace than most now expect, then $100 a barrel oil may seem an absurdly cheap price to have had to pay. It may even have an effect on the next Presidential election.

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Saturday, June 7, 2014

Waterjetting 22a - Mining horizontal coal

Over the last few posts I have discussed some of the problems that arise in dealing with the use of waterjets in mining coal, when the material mined has to be collected and transported away from the face where the coal is extracted. I thought I would follow on that thread in a few more posts, ending up, hopefully, where I began back in the process of removing thin layers of material (such as rust) from flat surfaces.

But to get there I am first going to go back to coal mining. One of the problems with adapting what we might call conventional hydraulic mining to coal is that many of the coal seams around the world are relatively flat – it is, after all, the way in which the vegetation that became coal was laid down. Thus the gravity that can be used in a steeply dipping seam as a way of carrying away the coal and the water together, is not initially that helpful.

There are several different ways that have been suggested over the years to solve the problem. Initially these were based on existing mining machines, and methods for mining the coal, but with the teeth of a conventional machine replaced with high-pressure waterjets. One such, as I have written earlier was the MS&T Hydrominer, where the cutting teeth along the edge of a coal plow were replaced with oscillating dual-orifice waterjets to cut a kerf around the coal being mined.

Figure 1. Artist’s impression of the initial Hydrominer, with jets cutting a slot one foot deep ahead of the wedge shape of the plow.

The water used was less than that conventionally used on a mining machine to suppress the dust generated as coal is mined from the solid, and the coal loads onto the armored face conveyor on which it rides down the face.

That particular design was based on an earlier mechanical machine, the Meco-Moore, which I had previously seen working on a longwall in the United Kingdom.

Figure 2. Meco-Moore mining machine set up to mine coal. The cutter jibs cut slots and the coal then collapses onto the transverse conveyor.

However this concept required a considerable investment in the supporting longwall equipment both to hold up the roof and to remove the coal. An alternative approach was to continue to conventional roof-and-pillar mining which is the most popular method of underground coal mining in the United States, but again replacing the cutting teeth with waterjets. The first of these was conceived by IIT Research Institute in Chicago, under Dr. Madan Singh.

Figure 3. A high-pressure waterjet continuous miner.

Unfortunately in this configuration the system did not work well. The jet pressures used were too high, and in consequence the volumes of the jets too low to achieve a deep penetration into the coal.

When the jets were replaced with a combination similar to that of the Hydrominer, and in a device we called RAPIERS, a slightly better performance was achieved, but the demand for innovation had, by that time passed for a spell, even though this particular machine was developed with considerable technical input and financial assistance from the Jet Propulsion Laboratory in Pasadena.

Figure 4. Progression of the RAPIERS machine in room-and-pillar mining.

Both of these machines required that a second set of machines sit behind the excavator and carry away the coal that had been mined, again at significant cost, and they also required machines to support the roof.

There is a different type of machine that is often used at the edge of the productive limit of surface mining. As seams near the surface get deeper so the cost of removing the overlying material becomes too expensive to justify continued mining. At that point companies may bring in an auger which can drill long holes into the coal, and remove the material as with conventional smaller augers that might be used for drilling in dirt (or even drilling holes in wood).

Figure 5. Conventional auger mining (Rosamine )

Because the auger drills a hole to the size of the following scroll, it is relatively easy to carry the coal back out of the horizontal hole, which might exceed 300 ft in depth. But there is a problem with the machine, in that the cutting force to push the auger teeth into the coal at the face of the machine has to be carried through the entire string of augers.

Because of the string of segments this becomes more difficult to control with longer depths, and in addition there is a friction loss due to the continual rubbing of the scrolls against the floor and sides of the hole. Together these act to limit the machine range, since there is little to steer the machine other than the direction of the hole, as it deepens.

Figure 6. Picks on the face of the auger, with early jets mounted in the center of the head to cut a central hole.

If, however, the picks on the face of the auger are largely replaced with waterjet nozzles, particularly at the outer edge of the auger, and with the flow directed there, rather than, as shown in Figure 6, towards the center, then an outer free face – up to a foot deep, can be cut ahead of the cutting head. With larger auger heads the nozzles can be placed across the face, to break the rib of coal, should it start to get too large – especially since the coal needs to be fragmented somewhat to feed down the auger.

Figure 7. Waterjets across the face of an auger (courtesy W.A. Summers)

The reduction in the amount of force that this allows on moving the auger into the coal can be illustrated by example. In developing a version of the machine we built an artificial coal face, made up of coal pieces and cement. It is a little more resistive than conventional coal, however the student, Chris Cannon, had little difficulty pulling the machine into the face with a come-along, even though he only had one uninjured arm at the time of the test.

Figure 9. Chris pulling the 2-ft diameter auger into the artificial coal seam.

By confining the coal and water it was possible to recover both, so that the water could, if needed be recycled.

I’ll continue the thread next post.

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Friday, June 6, 2014

Tech Talk - what the EPA Plan neglects

One of the problems, I suspect, with predictions of future energy use and production is that physical reality can become entangled in the politics of the day. Thus news that tends to negate the optimistic views of future American oil and natural gas production is subsumed by the need to keep the level of those predictions hecause of other political needs.

President Obama has now announced his decisions on a new incentive to combat his perception of the future as it sits threatened by the increased carbon dioxide produced by the burning of fossil fuels, particularly coal. As announced by the EPA, the Clean Power Plan “will maintain an affordable, reliable energy system, while cutting pollution and protecting our health and environment.”

The proposed rule has the intent of lowering carbon dioxide emissions by 30% from the levels of 2005, by 2030. As with many energy-related plans this one will take some time to implement, particularly since individual states have some input to the final program that will be put in place. More to the point, it will influence the thinking of power generators and legislators over the next few years.

Beyond the actual implementation, the real impact will be in the planning departments of the utility companies around the country. There is at least an even chance that, at some time in the future, these will become the regulations that must be followed, and as future power plant construction is planned, so the options that will be considered will now be changed to accommodate these likely regulations.

Realistically the closure of coal-fired plants will likely be followed by the construction of more natural gas plants, since the overall electrical energy needs of the country are unlikely to fall significantly. In the short term this is unlikely to be a problem. However as one moves into the intermediate term (say more than 5 years out) the old plants will have gone, and the country will become increasingly dependent on natural gas, in the same way as Europe is at present. As the old coal plants are demolished, they, and the coal mines that supply them, cannot be resurrected within a five-year period given the amount of permitting, financing and overall planning that is now required for such construction.

Natural gas has advantages over coal, in that it can be supplied by pipeline that makes it less susceptible to weather. But by the same token it is rarely stored on site, but metered along the pipeline as demand rises and falls. As history has shown, this can lead to critical shortages when, at times of high demand, the pipeline cannot keep up with demand.

At present the likelihood of problems seems remote, wells continue to be sunk and production in increasing in fields around the country. But if one goes beyond the picture that is projected as reassurance to those concerned for energy supply in the future the numbers revealed are not that comforting.

Figure 1. The changing picture of natural gas demand (EIA)

One begins with the prediction that the US has about 100 years of natural gas supply with a total extractable volume in reserves and resources of over 2,718 Tcf. It is a reassuring number but, as with the total volumes of either oil or coal in the ground, it does not really give that much information on what will be available as demand continues to rise.

Consider that, increasingly, the volumes of natural gas that are being sought are in shales, where the well must turn and drill along the shale horizon, before being fracked to produce gas and oil within the rock.

Figure 2. Number of rigs defined by type of well (Baker Hughes via EIA and Penn Energy)

The increasing dominance of horizontal well completions brings with it a considerable increase in well costs. You can see this as the technique became of increasing importance after 2005.

Figure 3. Change in the average cost of natural gas wells (EIA )

Well construction prices have continued to rise since that time, with numbers now running up to and beyond $10 million. The rising costs makes it harder to achieve a reasonable return on that investment, particularly as there has been no great increase in the overall price of natural gas to reflect its increased popularity, in large part because of the rush to drill and produce the known reserves.

Figure 4. Recent changes in natural gas prices (EIA )

As a result the number of rigs working in the natural gas fields has fallen, to the lowest levels of the recent past.

Figure 5. Change in the natural gas rig count over the past year. (Baker Hughes )

If you can’t make a profit on the merchandise, then after a while you stop trying to produce it. Despite the optimism that leads folk to anticipate large volumes of low-priced natural gas being able to sustain us into the foreseeable future if the companies cannot make a profit, after a while they stop. Which means that prices will go up, re-opening the cycle, but on a higher step. In time this will bring natural gas prices back up to around $8.00 per tcf, which will make the industry more comfortable.

What it will not do, however, will be to favorably impact the economics of the electricity business, where doubling the cost of fuel has a quite negative effect on prices and overall economics. But concerns over the rising price to be paid has had little impact yet on political decisions on energy in Europe, and one has to presume that a similar blindness to energy price consequences will also prevail in the United States. After all there is lots of natural gas around, it just has to be perceived as remaining a cheap fuel to validate the political plans . . .right ??!!

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