innovoilinnovoil note from the Editor]]>, 10 Apr 2019 16:04:04 +0000
Transport is at the centre of worldwide oil demand. Of the 100 million or so bpd consumed globally, around 65% goes on transport.
Electric vehicles (EVs) are threatening around 25 million bpd of oil that are used by passenger and light vehicles.
So far, EVs are being held in check by range and charging concerns. While incremental improvements to batteries are slowly adding to EV driving range, charging times are still an issue. It takes around 15 minutes for even the highest-end vehicle chargers at commercial charging stations to provide 80% of a battery’s capacity. When you’re competing against two minutes to fill a conventional car, this is nowhere near fast enough. And that is an extreme rate. Most chargers are much, much slower.
An EV’s lower range also means you need to charge more often. A new ICE car gets about 40-50 mpg, translating to an effective range of 650 km. EVs come in around 200-400 km, which translates to more frequent charging, and more time lost.
In the end, convenience is a prime determining factor for the pace of technology adoption. While the ability to charge at home overnight is touted as an attractive feature of an EV, it is irrelevant when you are far from home with a low battery. And anyway, in Europe at least, the majority of consumers do not have off-street parking in which to charge an EV.
This landscape makes Battrion’s new battery technology, which we cover in this month’s InnovOil, interesting. Most EV batteries use graphite anodes made of horizontally aligned graphite flakes. The lithium ions must migrate their way around these flakes. Horizontal graphite flakes make for longer slower pathways for those ions, slowing down charge times. Battrion aligns the flakes vertically, giving lithium ions a shorter route, so charging time falls.
Oil demand from cars is set to remain broadly flat as falling demand in the West is balanced by rising demand in the rest of the world. However, the global oil industry will not see its single biggest customer disappearing overnight. NB Research’s forecasts are still only pointing to around 60 million pure electric EVs, less than 5% of the 1.8 billion cars in service, by 2030, displacing a modest 1 million bpd of demand, a volume that is likely to be absorbed by increased demand from other sectors.
Marine bunker fuels account for a much smaller slice of the oil market – around 4 million bpd – but that market will transform steadily as regulators have their way. The IMO’s emissions regulations are forcing shipowners to move quickly to reduce SOx emissions. One solution is to replace fuel oil with LNG. In this issue we also cover the largest dual-fuelling project to date – conversion of the container ship Sajir to dual fuel. While there are still other technologies available to deal with SOx emissions (scrubbers or cleaner fuels), the Sajir conversion could be the start of a trend that will erode another, albeit smaller, market for oil.
The pace at which new approaches displace oil from transportation will be dictated by a combination of regulation, price and technological change. The last of these three arrives in small, low-profile steps. Read about those first here, in InnovOil.
Controlled burn]]>, 10 Apr 2019 13:37:29 +0000
LumaSense’s optical pyrometers help keep sulphur recovery units at the right temperature
The main reason refineries produce sulphur is simple – they have to. Regulations on sulphide gas emissions and sulphur content in fuels makes removing sulphur compounds necessary. Regulation has led where engineering already operated – sulphur wrecks process plant and pipework.
Sulphur recovery is usually a back-end process in a refinery. Removing sulphur compounds from sour oil and gas needs a carefully controlled band of temperatures – too cold and the reaction becomes inefficient or stops altogether; too hot and the reactor could be damaged. That makes sulphur recovery units expensive to install (around US$2-5 million) and difficult to run.
Around 90-95% of refineries use the Claus process to make sulphur. Hydrogen sulphide is burned with oxygen over a pre-heated catalyst bed (generally activated alumina) to produce water and sulphur dioxide. Then, more hydrogen sulphide is added to end up with water and sulphur. The Claus reaction is an equilibrium reaction, so the feed hydrogen sulphide is cycled through additional reactors, converters and condenser beds two, three or more times, until no more can be economically reacted – depending on the plant leaving between 0-5% of the gas. The first reactor in the step does the most work, removing 60-70%.
The burning process begins at reactor temperatures up to 925°C for flame stability, but optimisation comes at around 1,300°C. At each stage liquid sulphur must be condensed for extraction, for which the gas stream needs to fall to 140°C. Going outside these ideal operator ranges has serious consequences for the reactor, the refinery and the environment.
Temperature range
If the temperature gets too high it can damage the reactor, reduce its lifespan or in extreme cases cause the unit to leak hydrogen sulphide, which can be deadly at high concentrations. In low temperature cases the catalyst bed can be damaged, reducing the efficiency of the process to the point where unconverted hydrogen sulphide is vented through the stack. Since the reaction is exothermic this can happen if the mixture of gas and oxygen is wrong and the reaction gets out of control. The operator naturally wants to run the process at the highest safe level of throughput and constant accurate temperature measurement is the key to that.
For most refineries the sulphur recovery unit is an essential part of the overall flow process. If it stops, the refinery stops. Refineries commonly install a second sulphur recovery unit and additional hydrogen sulphide tanks, but this increases the investment needed.
If temperatures fall too low, ammonia and other contaminants will not be destroyed and will damage the reactor and catalysts. If the temperature falls below 925°C the reaction become unstable and can stop. If the temperature gets out of control on the upside it is not easy to correct quickly – heating or cooling rates above 50°C per hour can cause thermal shock. Cooling the reactor too fast can damage it (like pouring cold water on a hot plate). Ammonia, benzene, toluene, and xylene isomers found in the feed gas need temperatures of at least 1,250°C to be destroyed. While every sulphur reactor works to different tolerances, a safe temperature range is surprisingly narrow – 50°C either side of about 1,250°C. One approach to monitoring is to measure gas concentrations at each end of the process, but this does not give data on the inside of the furnace. Furnace temperature is the key measurement to optimising the reaction.
Watchful eye
However, the hot and caustic atmosphere inside a reactor makes it hard to gather data. In theory physical thermocouples can provide data, but are quickly consumed and replacing them requires the reactor to be powered down.
LumaSense has developed a range of optical pyrometers which avoid contact with the environment they are measuring as they operate by analysing the infrared light radiation emitted inside the reactor by the incandescent gas. Two independent infrared detectors measure different wavelengths on each sensor. The reactor chamber is a volatile environment of multiple gases (superheated steam, hydrogen sulphide, oxygen, nitrogen, sulphur dioxide and those pesky trace contaminants), all of which can interfere with an accurate temperature reading. By measuring two wavelengths a compensation calculation can be applied to balance out the emitted light and get an accurate reading.
LumaSense’s pyrometer also measures temperature gradients in parts of the furnace, such as the secondary combustion zone at the back of the furnace, where combustion products exit the reactor. The temperature of the reactor varies by much more than the target combustion range. For example the reactor wall is one of the cooler parts of the chamber – around 200°C cooler than the hottest part. Using infrared energy provides more data on heat distribution in the reactor. The reaction core is usually 1.5-2 metres into the furnace (depending on the size of the furnace and the burner design) and is the key area to measure. LumaSense gives the operator a full thermal image of the reactor, to support better decision-making in managing the process.
Anomalies can be detected in as few as 20 milliseconds, but in order to avoid burying the operator in readings the system provides a reading every second. It is accurate to 0.3% (4-5°C). When the pyrometer fails it can be removed and fixed without shutting down the reactor (they are usually installed in pairs) to support continuous operation.
Lumasense’s pyrometers are aimed at allowing operators to run at higher throughputs and with more uptime, while keeping these high-energy systems safe.
Smart lengths]]>, 10 Apr 2019 13:36:07 +0000
Software company Cimteq can help make a cable factory smarter
The complexity of making a cable brings to mind the old rhetorical question about how long is a piece of string. An appropriate image, as the length of a cable is one of the factors that make cable manufacturing difficult, although there is more to it than that.
Short simple cables, think phone chargers, can be easily mass-produced. Their design is a number of strands of metal conductor, normally copper or aluminium, twisted together and covered by plastic insulation. Once designed, mass production is trivial, and the customer simply selects from a product menu.
However, long complex cables used in oil and gas projects come with many more challenges. Subsea cables are exposed to corrosive salt water. They suffer violent impacts. Downhole cables have to operate reliably at high temperatures.
While cables find their way into just about every operation across the industry, the largest and most complicated are subsea umbilicals. These contain multiple different conductors of power, data, hydraulics, injection gas, and can stretch for thousands of metres. To prevent signal contamination conductors need to be insulated against each other, as well as armoured to protect against their harsh operating environment.
That makes them expensive. Lifespans are partly a function of layout – conductors can wear against each other. Poor layout makes the cable less flexible, also shortening life. Good cable design is, in short, a key input to maximising life and minimising depreciation.
Good design
Cimteq, a company based in Wrexham, UK, has developed a software suite to support the design and manufacture of cables. The company’s design tool – CableBuilder – helps the designer specify the detailed construction of a cable, and then anticipate the manufacturing issues to be solved by reflecting the actual manufacturing conditions on the shop floor.
It models the real world through a user-configurable set of machine and production rules. Doing this means that design and manufacturing both sit in the real world, not a theoretical perfect one. This in turn means less manufacturing wastage, quicker production runs and better quality assurance.
When it comes to the actual cable build, a key problem to manage is length. If a batch of a thousand pieces of a one-metre cable contains 1% that are too short, you lose 10 items, a small investment that can be made up quickly in the next batch.
If a single 1,000-metre cable is 1% short, the entire cable may be wasted. Overspecifying length may be an expensive way of covering that risk, and also, if the cable is designed to a specific length and task it has to be exactly the right size. Overspecification also generates waste and scrappage.
Equally, in a 1,000-cable batch you can discard failed cables, but if there is a manufacturing fault along a single 1,000-metre cable you have a much larger problem. Just locating where the fault lies in the cable is a challenge. In the event of a repair, it is difficult to correct the fault without weakening the cable or leaving a join, which might critically alter the outer diameter. In the worst case scenario, a fault might render the whole cable a failure.
Every process, element and metre contains a chance of error. The key data capture point in manufacture is length. Length counters are commonplace, and detect stops in production and communicate with operators to initiate repairs. They can also schedule an inspection once a set length of cable has been run. The next step for smart length counters is to alert other machines in the process to stop or slow down in sync. They can finally provide data on how an order is progressing.
Running on
Cimteq steps in here with its Cable Manufacturing Execution System – CableMES – which collates and collects length data from a user-designated set of machines (using the Historian tool to process data) and presents this to the operator on a tailored dashboard. This allows the cable manufacturer to hit exact lengths, and also combine data capture from test equipment live, to identify quality issues quickly.
While some materials used to make cables may be similar to one another, they function very differently. The supplier’s product codes can only differ by a single digit and human error can easily cause the wrong material to be used.
By logging the materials, CableMES’s Scan Materials feature provides an early warning of a difference between the bill of materials and raw materials. Catching this early can save tens of thousands of dollars in wasted time and material.
Cimteq believes that its suite of products is a central part of the expansion of the concept of smart factories into cable manufacture, which has historically been slow to adopt IT as a core component.
While basic sensors are becoming commonplace, it is rare to find a cable plant in which the data they produce is integrated and processed intelligently. The challenge is not one of computing power – while there are a lot of sensors, data processing can be effectively carried out on basic IT architecture. So, integrating Cimteq’s solutions into a medium-sized plant comes in at around US$100,000. Most of Cimteq’s work is retrofitting, which avoids disrupting production.
A length counter is the most versatile sensor for cable manufacturing and provides the minimum number of sensors to go into a smart factory. However, there other sensors that can provide usable information if it is properly communicated.
Temperature and pressure gauge readings can be collated with cable quality to find savings in materials and prevent scrappage. An automatic diameter measurement system can spot deviations in the dimensions of the cable, which may reveal an internal flaw. Scales too can reveal how a fault can be related to material use. Together, these can help speed along the diagnostic process.
Combining the pieces
The true genius of the smart factory is how it combines data from multiple sensors. Take a vibration sensor – this can detect abnormal vibrations with more sensitivity than a human being ever could. Vibrations are both a sign and a cause of a larger malfunction.
While on its own a vibration sensor can be used to diagnose and pre-empt a potential fault, by combing its data with data from a length counter and timing system, the length of cable made while the machine was vibrating can be tracked down and checked to ensure it was not damaged while the machine was malfunctioning.
In the end, data is only as good as the actions it can dictate. By using the data to control hardware and enabling people to make quality decisions, the smart factory comes to life.
A digital twin can aggregate the information from smart assets and product design knowledge to make a real time model of the factory. Not only can this help manufacturers organise the factory, it can form the basis of intelligent automated decisions. Digital twins can be written in a language more easily understood by a computer, so smart assets can better understand one another.
Automation is another distinguishing factor of a smart factory. While it is arguable that automation has been the basis of a factory since the Industrial Revolution, a smart factory combines automation with machine communication.
Robots, like the autonomous mobile robots visible in every report on Amazon’s warehouses, are an example of how advanced automation has become. These can be added to a factory without having to alter its layout and free up more valuable human staff from the dull work of moving components.
These can take orders from connected assets to bring raw materials to a machine before it runs out, or remove finished products.
3D printing has a place in a smart factory. Forget the crude plastics coming out of cheap consumer printers – complex and high quality metal and electronic parts can be made to order. A diagnostic system in a machine can communicate with an on- or offsite 3D printer to create a replacement part, reducing downtime. A smarter and better connected AI can look up a stock database to see if a spare part is available or make decisions on how urgent a repair is. With advanced enough predictions, replacements can be made or ordered before a part wears out.
The cable market was hit by a decline in demand around the turn of the century. However, the global energy transition will drive demand for energy cables by an estimated 5% per year until 2023. Investments in the renewable energy sector will drive investment in high-voltage cables, while electric vehicle growth, particularly in China and India, will see low-voltage cable demand grow.
Cable makers can use this growth to optimise their operations. As the factory evolves, it will be the smartest that thrive.
Pseudo dry gas]]>, 10 Apr 2019 13:34:47 +0000
A new liquid removal technique could make more subsea tiebacks viable
Tieback projects for marginal gas fields often face critical problems such as water and hydrocarbon condensation, which causes slugging. Larger diameter pipes are more prone to slugging, but reducing pipe bores increases friction and pushes pressures up. More problems arrive when maintenance demands temporarily reduce pressures. A tieback that works at 100% of design pressure slugs up when pressures are dropped for a turndown.
The usual solutions are to remove liquids at the wellhead, or to add compression, with its attendant power requirement, CO2 emissions and maintenance of components.
Effectively dry
WorleyParsons group company INTECSEA, via the Group Programme Management Office (GPMO) Innovation Hub, has developed another approach, in a new technique christened “pseudo dry gas”.
The approach installs up to four piggable liquid removal units in line with the gas flow. INTECSEA is currently keeping the exact process used confidential, but the units appear to be passive, with no moving parts in the gas stream. All supporting equipment (single phase pumps, controls and power distribution) are field-proven and readily available equipment.
The first unit removes part of the liquids. As gas flows up the system changes in pressure and temperature cause additional liquids to condense, which are successively removed by later units. The residual liquid hydrocarbons are reabsorbed into the gas stream towards the surface. Liquid removal is not complete but is effective enough to create an effectively dry gas hydraulic system.
The result is less need to compromise on pipe sizes, and so larger bores and less frictional pressure. With less pressure comes savings on power as well – because pseudo dry gas operates at a lower overall pressure.
After removal the separation units pass liquids up a second pipe, which is 4-6 inches (100-150 mm) in diameter.
The new system has a natural redundancy. If one of the four units fails then the system will still work, albeit with reduced performance. Sour gas will cause problems for pseudo dry gas, as it does for other systems. Coping with sour gas would increase capex dramatically, so there is no expectation of its use with sour reserves.
As conventional deepwater long-distance gas tiebacks use two pipes anyway (to allow turndown operations), INTECSEA sees the pseudo dry gas solution as not leading to a dramatic capex increase. The material and work remain the same, but are simply distributed differently, though capex costs do rise by around 5-8%. However, it looks like this added investment can bring a production win. According to integrated modelling from the OGTC (which we have not seen), recoverable reserves in the Northern North Sea could rise by around 40 bcm using INTECSEA’s tech.
Another benefit is that pseudo dry gas allows plant to be turned down by 90% – 10-15 points more than is common today. While in standard subsea tiebacks turndown causes a substantial liquids hold-up to build up in days, with pseudo dry gas the smaller volumes of liquids being transported mean slower liquids build-up, and so quicker restarts. Finally, it may well turn out that reducing pressure on wells increases their expected lifespan.
With lower production and tieback costs on offer, pseudo dry gas might make stranded gas fields in the North of Shetland, East and West Africa, offshore Australia and New Zealand and parts of the Mediterranean commercial.
Returning to that OGTC study, results are reported to include a 26% improvement in recovery rates over conventional subsea tiebacks, driving an increase of NPV by 34% over the next best development option.
For subsea compression to achieve similar recovery rates multiple stations in different locations would be needed, with associated fuel consumption and CO2 emissions.
The first trial of the pseudo dry gas system is scheduled to take place in the first half of this year. INTECSEA is in the process of qualifying the liquid removal units, which is likely to be done as a joint project with the OGTC and to include a number of operators and contractors. The current next step in the project is building the piggable liquid removal unit for test on a flow loop.
INTECSEA is looking to identify a pilot field for a live test by 2022.
Making shock waves]]>, 10 Apr 2019 13:33:48 +0000
China’s Xian University is developing an exploding wire fracking technique
A team at Xian University led by Professor Zhang Yongming is expecting to trial an exploding wire plasma generator as a fracking technique in April 2019.
An “exploding wire” setup feeds a large and steeply rising current (released from capacitors) down a 0.5-mm thick wire. A current rise of above 100 amps per microsecond is needed to vaporise the wire, releasing the energy needed to create the explosion.
The current melts the wire into spheroidal droplets (unduloids), but the current rise is fast enough then to vaporise the unduloids before they can move. As the current continues to increase resistance also rises, until the vapour becomes a plasma. As this expands it creates a powerful shock wave, disrupting the plasma and so cutting the current.
Prof Zhang’s theory is that the shock wave can be used to fracture deep and dense rock formations. While details are sketchy, it appears that the plan involves extracting the “energy rod” after each shot and pumping high-pressure water (and presumably proppants) into the fractured formation before the next “shot” is fired.
Reports seem to suggest that the device can deliver pressures of 200 megapascals (29,000 psi), and has created fracture zones of around 50 metres. The system has already been reportedly used to release coal-mine methane – a significant problem in China’s coal mines, and also now a significant source of energy. Coal-mine methane (distinct from coal-bed methane, CBM) is widely used in China to power mine power plant and to generate heat for mine services. The device also appears very similar to the plasma well-stimulation process developed in Russia by Novas Energy and now licensed in the US by Propell.
The Novas system is designed for re-stimulation of stripper wells rather than fracking new ones, and Novas claims that its effects on reservoir rock extend out to 1,500 metres from the well bore. Novas has conducted numerous stimulation jobs and the resulting data appears to corroborate that effect, though InnovOil could not find any recent test results or progress announcements either from Novas or Propell.
Novas appears to place its exploding bridge wire (EBW) inside a fluid container, which looks like a means of moderating the pressure pulse from an intense/short-range pulse to a less intense/longer-range combination of pulses with a very wide frequency range.
Shock waves
As it seems likely that the Xian device will be completely destroyed by its own detonation, its use in fracking looks problematic. Again, details are not in the public domain but presumably the capacitors are kept on the surface, with new detonators being dropped at intervals into the well-bore. There is no hard data on how proppants are to be deployed into the fractured rock between shots.
The same “exploding wire” approach is used in the detonators for implosion-based nuclear weapons, as it provides an almost instant and precisely timed set of triggers for the detonators that fire the explosive lens.
However, while the EBW is common to both solutions, Prof Zhang’s work is completely detached from nuclear weapons development. EBWs operate 1,000-10,000 times faster than a conventional heating wire. Because of their use as triggers for nuclear weapons EBWs are heavily regulated in the US, and cannot easily be exported. US attitudes to the proliferation of EBW technology are likely to obstruct the use of Prof Zhang’s solution outside China, if indeed it is successful anyway.
On the Radar]]>, 10 Apr 2019 13:30:49 +0000
Liquid metals deliver solid performance
Scientists from Melbourne’s RMIT University have developed a way to convert carbon dioxide (CO2) into solid carbon at room temperature.
Their technique uses a specially designed liquid metal composed of gallium, indium and tin, with a layer of cerium oxide and cerium nanoparticles on the outside. The gallium core makes the alloy a liquid, while the cerium outside makes for an efficient electricity conductor and a chemically active surface.
By adding a small amount of the liquid metal to an electrolyte liquid (dimethylformamide-based in RMIT’s experiment) along with dissolved CO2 and passing an electrical current through the mixture, flakes of carbon develop on the metal’s surface.