May 31, 2008

Bitumen and Politics

The story of congestion-busting marvel and how it has been delivered on budget and six months ahead of schedule.

The delivery of this vital piece of infrastructure is a sorry tale of government incompetence. The Tugun Bypass is years overdue and has cost taxpayers hundreds of millions of dollars more than it should have.

Here are some facts that you won't hear at the community open day:

• Every metre of the 7.5km four-lane bypass cost taxpayers $72,800 – making it one of, if not the most, expensive road built in Australia on a per-kilometre basis.

• It was first mooted more than 12 years ago to fix traffic delays experienced by commuters between Currumbin and the NSW border.

• In 2001 the bypass was estimated to cost $157 million with work due to start the next year. Nothing happened.

• By 2002 the cost had jumped to $240 million.

But the NSW Government intervened to scupper it on environmental grounds. During the 2004 election an alternative route costing $360 million was unveiled.

Months later the cost of the original route also jumped to $360 million after Queensland agreed to meet an array of environmental concerns raised by the NSW Government. The bill then went up to $518 million before settling at $543 million in February 2006 when work finally began.

So the cost to taxpayers of five years of inaction, bureaucratic bungling and infighting between governments is a grand total of $386 million.

For that price increase and the years of traffic delays, there better be more than just free sausages for locals at Sunday's open day.

By Steven Wardill

Rubberised Bitumen


Increasing pressure by the vehicular traffic on the road is compelling highway authorities to look for high performance bitumen, obtained by modifying it with natural rubber.

Because of the positive elements in it and being cost effective, rubber-modified bitumen is an ideal proposition in the construction of highways, say experts.

Attempts had been made to modify the bitumen with plastomers and elastomers. ``Of these it was found that the natural elastomer, natural Rubber , was the most suitable modifier because of a number of reasons.

The advantages of NR in bitumen are that it is cost effective; does not induce stiffness to force road to brittle; improve resistance to flow at high road temperatures; easily blend with bitumen and its is readily available, he said. Besides, the natural rubber modified bitumen (NRMB) has superior properties in terms of penetration, softening point and elastic recovery, less affected by temperature fluctuations and improves skid resistance thereby enhancing road safety, he said.

NRMB roads are more resistant to brittleness, less rutting or permanent deformation and more resistant to fatigue and conserves energy.

Roads surfaced with NRMB provide at least 50 per cent more service life than ordinary bitumen roads while the price of NRMB is 7 per cent more than that of the other. Besides, experience has shown that the NRMB roads could cut maintenance cost by 30 per cent. Also, the fuel consumption of vehicles plying on such roads is expected to be reduced by 10 per cent, he said.

Meanwhile, according to two experts with the Rubber Board, different types of bitumen as polymer-modified bitumen (PMB), NRMB, and crum rubber-modified bitumen (CRMB) are being used in the country in road construction, especially in highways and the performance is observed to be promising.

Based on this, the Indian Road Congress (IRC) has approved the use of modified bitumen and consequently the Union Ministry of Road Transport and Highways has already issued guidelines and instructions for its use in highway construction.

The preliminary performance study of these roads conducted by the Central Rod Research Institute (CRRI), New Delhi, is observed to be promising. ``There is positive response from the National Highways Authority of India to use NRMB/CRMB for their renewal works and development projects,'' they said

May 30, 2008

Bitumen


Bitumen is black material with origin dating back 4000 years B.C. In Latin it was called Pixtu-Men.

Mis(sed) Concepts

Bitumen is often confused with tar. Although bitumen and coal tar are black and sticky, they are distinctly different substances in origin, chemical composition and properties.

Bitumen is an oil based substance. It is a semi-solid hydrocarbon product produced by removing the lighter fractions (such as liquid petroleum gas, petrol and diesel) from heavy crude oil during the refining process.

Coal tar is produced by heating coal to extremely high temperatures and is a by-product of gas and coke production.

Bitumen shall not be confused with petroleum pitch which, though derived from crude oil, is a substance produced by a different process . Petroleum pitches are the residues from the extreme heat treatment or “cracking” of petroleum fractions. They are quite different in properties and chemical composition from that of refined bitumen.

Naturally-occurring bitumen, sometimes also called natural asphalt, rock asphalt, lake asphalt or oil sand, has been used as an adhesive, sealant and waterproofing agent for over 8,000 years. But it occurs only in small quantities and its properties are quite different from refined bitumen.

Asphalt

Asphalt is typically a mix of approximately 95 per cent aggregate and sand, and five per cent of bitumen, which acts as the binder. Asphalt is fully recyclable and recycling has increased significantly in recent years.

In North America, Asphalt refers to Bitumen.

Bitumen Types

· Refined from Crude Oil produced in refineries. ( most common)

· Tar - produced from coal.

· Natural bitumen ( mine from nature requires refinement)

Grades

· Paving Grade

· Roofing Grade.

Chemical Composition

The two groups of Hydrocarbure are namely Asphaltine, and Maltin.

· There is 5-30% Asphaltin in bitumen which causes the hardness of the bitumen.

· Maltin is made of grease and resin.

Process

The heaviest derivative which is separated from crude oil in the Vacuum Distillation unit is the residue of the vacuum distillation which is briefly referred to as “vacuum bottom” or VB. This residue is the main feed for bitumen producing unit.

The feed is oxidized using air till the feed reaches desired properties of bitumen such as the penetration number and softening point .

Controliing the operating parameters such as the temperature of reactor, residence time in the reactor, and the air to feed ratio it is possible to produce different grades of bitumen.

Proper additives in the process enables the production of modified bitumen like Polymer Modified Bitumen (PMB) which is highly resistant.

Another bitumen product is bitumen emulsion which is gradually substituting cutbacks for its environmental cleanliness as well as energy consumption savings.

May 29, 2008

Bitumen Cartel Exposed by EU



The European Commission has fined some of the region's top oil firms including Shell and Total for their role in a cartel that fixed the price of bitumen.

In all the companies were fined $338m (£180m; 266.7m euros), with Shell getting the largest penalty of $137m.

The fines were based on the size of the companies, the extent to which they were involved, and whether or not they had previously broken competition law.

UK oil firm BP informed officials of the cartel and cooperated in the probe.

Shell - The Repeat offender

The Commission said that between 1996 and 2004, eight suppliers and six road builders worked together to control bitumen prices in the Netherlands.

Along with Shell, it implicated the international oil firms BP, Total and Kuwait Petroleum.

Total received a fine of $25.7m for its part in the affair. Kuwait Petroleum was told to pay $21m.

BP escaped without any fine at all because of its role as whistle-blower and help with the subsequent investigation.

But Shell was penalised very heavily.

"The fines for Shell were the highest because it was a repeat offender and because it played a leading role in the cartel," said the Commission's spokesman Jonathan Todd.

The fines were the seventh largest total penalty the regulator has ever imposed in a cartel case.

Shell has previously been fined by the Commission for price-fixing in the markets for PVC and propylene.

The company said it would examine the decision in detail before deciding whether or not to appeal.

New rules

The Commission also took a hard line towards the Dutch road building firm Koninklijke Volker Wessels Stevin.

It said the company had tried to impede its investigation by denying inspectors access to its premises and forcing the national police force to become involved.

The company was ordered to pay a fine of $34.6m.

The bitumen probe reflects the Commission's determination to clamp down on companies which break EU competition laws, especially those which do so repeatedly.

Courtesy -BBC

F1 Track in Singapore

Shell Cariphalte Racetrack was selected by the Singapore Land Transport Authority (LTA) as the binder material solution to be used by main contractor, for the racetrack due to its ability to withstand the demanding conditions created during a Formula One race. The inaugural Singapore Grand Prix will be staged on a new street circuit, which will be open to regular motorists throughout the year.

With its high shear and stress properties, Cariphalte is a well-designed, high-performance binder that allows enhanced road performance in terms of resistance to extreme heat, rutting (or deformation), cracking, stripping and ageing. The physical properties that make Shell Cariphalte Racetrack suitable for these high-stress surfaces is a Styrene Butadiene Styrene (SBS) concentration which ensures a three-dimensional network within the bitumen. The product is designed to have increased stiffness at high temperatures, to better withstand high temperatures and has a substantially increased elasticity, helping to reduce cracking.

Cariphalte Racetrack meets all Fédération Internationale de l'Automobile (FIA) stringent track requirements and has been used on other high-stress surfaces, including Bahrain's Formula One track and Malaysia's Sepang circuit. Products from the Cariphalte range were also recently used for the runway upgrade at Singapore’s Changi Airport to accommodate the Airbus A380.

May 28, 2008

Kenya - To produce or to Import ?



Image
Kenya’s sole refiner is to adjust its charges by about 10 per cent to $2.35 per barrel (159 litres) from October.

It will be the second increase in two years after another one was effected in 2006 by the Kenya Petroleum Refineries Ltd, raising the processing cost from $1.70 to $$2.15 per barrel.

“The refinery has written to us about the plans. Margins are already depressed and we will have to pass on to consumers,” said industry sources .
Industry players however, are opposed to the plans saying it favours importation of white oil.

“In order to process crude oil, there has to be a positive processing margin. If the processing margin is negative, you are better off importing refined products,” said a source who did not wish to be named.

For a long time now, the processing margin at KPRL has been negative, sometimes to the order of $40 per metric tonne or more, meaning oil companies will not prioritise processing in the Mombasa refinery, even at a marginal processing fee of say $1 per barrel.

“The main advantage of importing oil products is that you import only those products that you require, in the quality that you require, and when you require them,” added our source on condition of anonymity.

Each quarter, Kenya’s sole refinery receives some 450 000 tonnes for processing into various white products on behalf of oil markets and consumers. Under the law, oil marketers are required to process 1.6 million tonnes of crude every year at the facilities.


KPRL refines 75 per cent Murban (light) and 25 per cent Arabian medium. The Kenyan supply pattern is normally driven by dual purpose kerosene and diesel demands, meaning select crudes and also select yields that maximise the two products are prioritised.


Gulf Energy - a new entrant to the local market cites KPRL’s capacity to produce high end products competitively as the main reason why locally processed products cost more than imports, putting pressure on profit margins.

KPRL’s products, including liquefied petroleum gas, unleaded premium gasoline, regular petrol, automotive gasoil, industrial diesel, fuel oil and special products like bitumen and grease are sold into the Kenyan market and exported to neighbouring countries including Tanzania, Uganda, Burundi and Rwanda.

Total demand for products in these markets is estimated at five million tonnes per year, three million of these are consumed in Kenya alone.

Bitumen Supply Delay_ Another day at the Court

A lawyer representing Kirinyaga Construction Company asked the High Court to refer a dispute involving Sh78 million to an arbitration panel.

However, the company’s suppliers Bobbin EPZ Limited, insisted the dispute could only be heard and determined by the court, since no contractual agreement was entered between the two parties.

Mr. C.N. Kihara asked Justice Jessie Lessit to block Bobbin EPZ from enforcing bank guarantee payments until the matter was resolved.

The lawyer submitted that Kirinyaga, which is associated with Mathira MP Ephraim Maina, was ready to make payments for monies owed to Bobbin for the supply of bitumen. He, however, called on the court to determine the amount due for payment.

Soured relationship

Kirinyaga moved to the High Court after it discovered that the delivery was 200 tonnes less than what had been ordered from Bobbin.

After a series of meetings and communication between Kirinyaga and Bobbin to resolve the dispute, the relationship soured and the matter was referred to the Milimani Commercial Court.

By a written agreement, Bobbin was to supply Kirinyaga with 6,000 metric tons of bitumen at a cost of Sh 39,450 per tonne.

However, Mr Kihara told the court that there were delays in delivery. Thereafter, the relationship between the two deteriorated and the construction company moved to court.


Bobbin went ahead and presented the cheques for payment despite Kirinyaga’s pleas against that. Mr Kihara asked Justice Lessit to restrain them as they would expose his client to losses.

Bobbin, through Muthoga Gaturu and Company Advocates termed the suit before Lessit as an abuse, claiming that the orders sought by Kirinyaga Construction were illegitimate and lacked merit.

They further claimed that the four bank guarantees of September 2007 issued by National Bank of Kenya for Sh78 million were issued after Kirinyaga had been satisfied with the delivery of materials to their site in Sagana.

Bobbin said they only delayed delivery in December and January due to the post-election violence and the failure of Kirinyaga Construction to honour earlier payments.


May 27, 2008

Saudi is Spending 129 Billion


SAUDI ARABIA.

Saudi govt annual earnings from a modest 70 billion has risen to 300 billion per annum last year due the high oil Price.

The good news is besides funding Islamic education in western countries, Saudi is investing back , where the mouth is.. Pls read on....

State oil giant Saudi Aramco plans to invest US$129 billion on new energy projects in the next five years, the company's executive vice president of operations said on Sunday.

Saudi Arabia is the world's largest oil exporter and Aramco is expanding to increase crude, gas, refining and petrochemical capacity.

About US$70 billion of the total would be spent by international and domestic joint ventures, and the remaining US$59 billion on projects solely undertaken by Aramco, Khalid al-Falih told Reuters.

The US$129 billion figure is nearly US$40 billion higher that previous estimates given by Saudi official for expansion.

The world's largest oil company by production and reserves has drawn up an exclusive list of 27 selected Saudi and international construction and engineering firms vying for the contracts due to be awarded.

Seven decades of large-scale commercial production has managed to deplete only 28% of Saudi Arabia's proven reserves. Estimates point to recoverable oil of 200 billion barrels, enough to last, at last year's average production level, for over 100 years.

Another complex is planned to be located at Yanbu. Aramco has a 25% stake in a 240,000 bpd refinery venture in China's Fujian province which will chiefly draw on Saudi heavy crude to produce gasoline and petrochemicals.Sinopec is mulling a second joint venture refinery with Aramco in Shandong province.

A US$5 billion refinery investment is being mooted on Mindanao island in the Philippines, where Saudi Aramco has a 40% stake in a refinery.

Total investment would be higher as it would include some of the US$65 billion that Aramco is investing in projects that are already under way.

Aramco's oil output capacity would reach 12 million barrels per day by the end of 2009, Falih said.

Aramco capacity does not include production from the Neutral Zone between Saudia Arabia and Kuwait. Including the zone, Saudi Arabia is aiming to reach a total crude capacity of 12.5 million bpds.

Improving Bitumen Performance


The actual performance of the bitumen is just one part of the total performance of a bitumen / aggregate mixture. This depends on a number of factors including the design of the mixture, the way it was mixed and how it was laid and compacted. As bitumen is an integral part of the total mix, advice on how to avoid and correct errors would need to cover many factors and types of mixture.

It is possible to add some guidelines to optimize the performance of bitumen, mainly in hot bitumen/aggregate mixtures, based on the knowledge of bitumen itself.

Tips

Minimize the time during which hot bitumen is exposed to air. Bitumen hardens and loses some of its adhesive property when it is exposed to a combination of air and heat.

Bitumen shall be kept dry and away from contamination by water at all times. When it comes into contact with water it will foam.

Keep bitumen within the range of temperatures recommended for the type and grade. Bitumen solidifies as it cools and becomes unworkable, and the viscosity may increase if it is overheated. It is sensible to use bitumen at the lowest temperature that will permit it to be mixed, transported and compacted but in any case the maximum storage temperature relating to the grade should not be exceeded during the mixing process.

Temperature control is a major factor in the quality control of a bitumen / aggregate mixture. Avoid contaminating the bitumen, particularly with petroleum based solvents that reduce the Flashpoint and the viscosity and increase the penetration.

Just 0.1% diesel oil in a bitumen / aggregate mixture can lower the flash point and increase the penetration significantly.

Stability is an essential quality in the performance of a bitumen / aggregate mixture. it depends on friction and cohesion within the mixture. Too much bitumen actually acts as a lubricant for the aggregate particles, reducing friction and therefore the mixture's stability.

The cohesion or internal binding force in the mixture increases as the proportion of bitumen in the mixture is increased, until it reaches the optimum. if the amount of bitumen is increased further, stability decreases. it is therefore essential to ensure that the optimum proportion of bitumen is used in any mixture.

Finished mix should be frequently observed. Early warning signs that further checks should be made:
  • If the distribution of bitumen on the aggregate is not uniform, the temperaturein the mixing operation was too low
  • If the mixture looks stiff & dull rather than black and shiny there may be toolittle bitumen in the mixture
  • If the mix lies slumped on the floor ,there may be too much bitumen in it.
  • Blue smoke coming from the mix can indicate overheating
  • Steam coming from the mixture indicates the presence of too much moisture

May 26, 2008

Add Color to Bitumen


Bitumen manufacturing exploits the advanced technology available to the oil industry for the development and quality control of petroleum products. Its application is leading to the establishment of new levels of understanding of bitumen's qualities and its potential advantages to end-users. The use of gas chromatography with electronic measurement apparatus to identify the chemical composition of bitumen made from various feedstock, and the correlation of this information with measurements of their road performance, is one such example of the practical benefits of this work.


The continual international increases in road traffic, particularly heavy freight -carrying vehicles, and the cost of maintaining existing highways and constructing new ones have brought new demands from bitumen users. They want the bitumen of the future to
include specific improvements to their characteristics, particularly in the following sectors:

  • Resistance to degradation at high temperatures
  • Improved ageing, i.e. resistance to degradation with time
  • Improved workability, allowing road courses to be laid under a wider range of temperatures and weather conditions so that the effective season for roadwork isextended.
  • Resistance to cracking and deformation
  • Tolerance towards poor workmanship
  • Increased adhesion to minerals

An example of the results of the work is the marketing of one of the first modified bitumen incorporating an elastic-thermoplastic copolymer. The result is a hard or semi-hard binder with an enhanced plasticity range, excellent adhesion to aggregates and enhanced fatigue and deformation characteristics. In common with other products of this type, it requires a specialized blending plant.

Colored bitumen offer great scope for imaginative application where there is a need to differentiate surfaces according to their use or to have a surface in harmony with its environment. They may be divided into two distinct types.


The first type comprises bitumen that have been specially prepared by selecting feedstock with a low proportion of asphaltene. Pigments are then mixed into the bitumen. The result is a colored bitumen where the colors are muted by the presence of asphaltenes. This limits their application to a certain extent.

The second type may accurately be described as translucent binders to which colors are added. They perform the same function as bitumen and can be made successfully in a broad range of colors, but they are not made of the same material as conventional bitumen.

The development of modern bitumen although not as fast as the super-computer it consistently exploits the results of today's advanced technology to meet the future demands of mankind.

May 25, 2008

Bituminous Pavements

Modern asphalts roads, with a solid base course and protective replaceable wearing course, are now designed to last for over 40 years and with correct surface maintenance they can last even longer.

Noise reduction

Use of asphalt road surfaces can significantly reduce noise both inside and outside the car, preventing accidents by alleviating a source of stress that contributes to driver fatigue. After speed and alcohol abuse, driver fatigue is the next most frequent cause of accidents.

Standard asphalt roads have the lowest noise levels of the traditional road surfaces and the recent development of porous and silent asphalts have reduced noise levels even further. A standard asphalt surface produces half the noise generated by a standard concrete surface and porous asphalt reduces this by a further 50 per cent.

Surface water dispersal

New asphalt technology ensures rapid dispersal and drainage of surface water, reducing water spray and therefore improving visibility for the driver in wet conditions. The new porous asphalt materials dramatically reduce blinding spray and by dispersing surface water they also reduce the risk of aquaplaning and increase the visibility of road markings.

Skid resistance

Drainage and texture of the road surface are the two crucial elements that aid skid resistance. Much research has been dedicated to the removal of water and provision of vehicle tyre grip. The drainage capability of porous asphalts and precision in aggregate mix play a vital role in skid resistance.

Today’s asphalt surfaces have been developed to provide a skid resistant texture, without the need for protruding aggregates that contribute to traffic noise. They therefore also give the driver a smoother ride.

Asphalt surfaces that provide higher levels of skid resistance can be used where safety is paramount, for example, outside schools or where there are extreme road gradients or bends.

Easy maintenance - less traffic disruption

Asphalt roads can be easily opened and quickly reinstated to install or repair utilities. This speed in accessing water mains, gas pipes, or telephone cables is crucial in minimising the associated congestion and driver frustration.

Clearer lane marking with coloured asphalts

Another recent asphalt advance has been the development of coloured surfaces. These are increasingly used as a safety mechanism to make it easier for drivers to identify lanes set aside for special uses, such as bus lanes, bus stops and cycle paths. Coloured asphalt is also used to alert driver attention to dangerous areas such as hidden junctions or sharp bends.

Totally recyclable

Asphalt is 100 per cent recyclable and is routinely milled and re-laid along with fresh materials, saving money and preserving non-renewable natural resources.

Recycling also reduces the use of virgin quality gravel, preserves landfill and saves transport.

Versatile and flexible

Asphalt surfaces can be ‘tailor-made’ – appropriately formulated and designed to support the traffic load and climatic conditions of a specific road. There are asphalt solutions for motorways, urban, suburban and rural roads and its flexibility is particularly useful in coping with the stresses of large traffic loads on bridges.

In areas where roads have to cope with frequent freezing and thawing, thanks to the elasticity of bitumen, asphalt surfaces can be designed to tolerate extreme temperature cycles. Where studded tyres are used in cold climates, the maintenance advantages of asphalt are also critical.

After construction the flexibility of asphalt allows for easy surface improvement and road widening, as new requirements arise.

Courtesy-Eurobitume

Factors Affecting Asphalt Compaction




Compaction is the process of densifying, or reducing the volume of, a mass of material. Most practitioners consider achieving appropriate compaction critical to the performance of an asphalt pavement. For asphalt mixtures, compaction locks the asphalt-coated aggregate particles together to achieve stability and provide resistance to deformation (or rutting) while simultaneously reducing the permeability of the mixture and improving its durability.

There are many factors that affect the compactability of asphalt mixtures. Among those factors are the properties of the asphalt mixture, the type and density of the underlying base course material, the thickness of the asphalt layers, and the environmental conditions at the time of placement. If any of these factors change, the final modulus, stiffness or strength of the mix will be directly affected. Additionally, the final compactability of the mix is affected by the type of rollers, the number of rollers, and the rolling patterns used during the compaction process.

Asphalt Mixture and Pavement Variables
There are a wide variety of asphalt mixtures currently being used in North America. Among those mix types are dense graded mixes, open graded mixes, and stone matrix asphalt (SMA) mixes. Within the realm of dense graded mixes, some of the mixes are fine graded mixes, some are coarse graded mixes, and some are very densely (uniformly) graded mixes. Some of the open graded mixes are used for friction course layers while some are used as a permeable base course layer. SMA mixes, which are usually very dense graded, typically have a significantly different gradation than normal dense graded asphalt mixes and incorporate an increased amount of mineral filler as part of the gradation. Gap graded asphalt mixes are also used by some agencies.

There are also many types and grades of asphalt binder materials currently being used. A few of those binders are still graded using the penetration system, some are still viscosity (AC) graded, while most meet at least some of the criteria for a Performance Graded (PG) asphalt binder. Further, some of the asphalt binders are polymer modified, using either elastomeric or plastomeric type materials. Asphalt rubber binders are also used in some asphalt mixtures. Each of these types and grades of asphalt binder materials will affect the degree of stiffness obtained in the asphalt mixture, both at the time of construction and throughout the compaction process.

The effective asphalt binder content of the asphalt mixture also affects workability and compactability. As the asphalt binder content increases, the film thickness on the aggregate particles increases. At compaction temperatures, this increased film thickness enhances the lubricating effect of the asphalt binder, and, up to a point, makes mix compaction easier.

Aggregate Influences
There are a wide variety of aggregate types currently being used in North America. Some of those materials are sedimentary, some are igneous, and some are of glacial origin (gravel). In addition, the absorption, soundness, angularity, surface texture, and degree of flat and/or elongated particles all affect the properties of the different aggregate materials and, therefore, the properties of the asphalt mixture into which they are incorporated. In particular, the amount of crushed coarse and fine aggregates in the mix has a direct affect on the stiffness and compactability of the resulting mixture.

Volumetric Property Considerations
The volumetric requirements for the various asphalt mixes vary widely. In many jurisdictions, voids in mineral aggregate (VMA), voids filled with asphalt (VFA), and air void (AV) content requirements are included as part of the mix specification specifications. In some places, Hveem mix design methods are still popular and, in general, the Hveem mix design methods do not require the calculation of the VMA or VFA values of the mix. It is well known that the volumetrics of the asphalt mixture have a direct affect on the performance of the mix under traffic. The volumetrics, however, also have a very dramatic affect on the stiffness of the mix during the compaction operation and on the ability of the contractor to achieve the desired level of compaction.

Environmental Effects
The environmental conditions at the time of mix placement can directly influence the amount of compaction obtained by affecting the time available to compact the mix—the cooling rate of the mix. Air temperature, base temperature, wind velocity, and solar flux or cloud cover (to a minor degree) all govern the cooling rate of the mix and the ability of the contractor to obtain the desired level of density in the asphalt mix. The environmental conditions are different on each project and will affect the level of density obtained with each pass of the compaction equipment.

Base Conditions
The effect of the base type and condition is also a factor which affects the level of stiffness or compaction achieved in the new asphalt layer. The amount of compactive effort needed depends, in part, on whether the new asphalt layer is placed on top of the subgrade soil, an aggregate base course, a cold mix asphalt layer, a cracked asphalt pavement layer, a new asphalt concrete layer, or a Portland cement concrete pavement layer. In addition, the thickness of the asphalt layer being placed is also a factor to be considered when attempting to compact the mix. Thinner asphalt layers will cool faster than thicker layers.

Lift Thickness and Particle Size
In general, thick lifts of asphalt mix can be compacted more easily than thin lifts. The thicker the lift, the longer the heat is retained, and thus there is more time for the rolling to take place.

As a general guideline, for finer dense graded mixes (those plotting above the 0.45-power chart maximum density line), the minimum lift thickness should be three times the nominal maximum aggregate size. Similarly, for a coarse graded mix (plotting below the maximum density line), the lift thickness should be at least four times the nominal maximum aggregate size. These guidelines provide sufficient lift thickness for the aggregate particles to re-orient and pack together during the compaction process.

Mix Temperature
It has been said that the three most important factors that affect the ability of a contractor to achieve the desired level of density in an asphalt mix are, in order of importance, temperature, temperature and temperature.

Asphalt mixes can be divided into two primary categories as far as the resistance to compaction is concerned. Some mixes are stiff and are difficult to compact. Some mixes are tender and move excessively under the action of steel drum rollers. The tender mixes generally will check or crack in the “middle temperature zone.” Instead of gaining density when the mix is rolled in the middle temperature zone, density is often lost when the mix moves in front of the steel wheels on a double drum vibratory roller or a static steel wheel roller.

The roller pattern used to compact a stiff mix is typically significantly different than the roller pattern used to compact a tender mix. Because of the three temperature zones usually found when compacting a tender mix, the stiffness of the mix at a particular temperature may not be related at all to the final density of the mix.

The temperature of the asphalt mix is continually changing during the rolling process. The rate of cooling of the mix is related to a number of factors such as the thickness of the layer being compacted, the temperature of the mix at the time it is extruded from under the screed on the paver, the properties of the asphalt mix (dense graded or open graded), as well as the environmental conditions such as air temperature and wind velocity.

The temperature at which an asphalt mix is produced affects both the ease of compaction and the time available for compaction. The time available for compaction increases with mix temperature, but there are limits as to how high the production temperature can be in order to avoid damaging the asphalt binder.

The continually changing mix temperature is the primary factor that makes prediction of the ultimate density of the mix when rolling is completed so difficult to estimate during the actual rolling process itself.

The goal in compacting an asphalt mix is to produce a smooth, stable and durable asphalt pavement. Understanding the factors affecting compaction is an important step in achieving this goal.

By James A. Scherocman, P.E. and Dwight Walker, P.E.

Jim Scherocman is a consulting engineer specializing in asphalt pavement design and construction.

Stolt-Nielsen Enters Asian Bitumen Tanker Market





Stolt-Nielsen S.A. (SNSA) (Oslo Børs: SNI), announced today that it has signed an agreement with Xinshun Shipyard in China for the purchase of up to six 5,900 deadweight ton (dwt) bitumen tanker newbuildings due for delivery from February 2010. Under the terms of the agreement, SNSA has placed firm orders for two ships and holds options to purchase a further four ships. It is intended that a new division of SNSA will be established in Asia-Pacific that will provide logistical services for the distribution of bitumen.

Mr. Niels G. Stolt-Nielsen, Chief Executive Officer of SNSA, said, "This investment in new, superior performance bitumen tankers represents our entry into an attractive sector, in a region where SNSA has long been one of the leaders in the chemical products transportation market. We are very pleased to have secured these high quality newbuildings from the Xinshun Shipyard, which will allow us to meet the demanding intra and inter-regional transportation needs of our oil refiner and industrial customers."

Oil and Nigeria


The prices of Bitumen and Oil is climbing day by day and as Mr.Narayanan was quoted saying that the real value of the natural resources in Nigeria is not helping Nigerians.

The attack on Shell Facility, bombing the pipeline , kidnapping the Engineers by Nigerians, beside politics the fundamental reason may be poverty and uneven sharing the of the resources.

Militants in Nigeria have blown up an oil flow station belonging to the Shell company in the Niger Delta, causing it to cut some of its production.

It is the fifth attack on the oil industry in recent weeks, reducing output and pressuring global prices.

It is not yet clear which group was responsible for the attack.

Several previous ones have been blamed on supporters of the militant leader Henry Okah, who is currently awaiting trial on treason charges.

The attack came a day after a Nigerian federal court ruled Mr Okah, from the rebel Movement for the Emancipation of the Niger Delta (MEND), should be tried in secret.

Shell accounts for around half of Nigeria's 2.1 million barrels per day of oil output, and has already been forced to cut production because of a pipeline bombing last month.

"A few oil delivery lines are affected and some oil has spilled into the environment," a Shell spokesman said after the latest attack.

"We are mobilising containment booms to stop the spread of oil and have also shut in some production volumes."
Source- BBC

Husky's Bitumen venture



Husky Energy Inc. officially opened its $500-million Tucker oil sands project in October, 2006, on time and slightly under budget – a rarity in northeastern Alberta.

The goal was to produce 30,000 barrels a day of bitumen by late this year. It's not even close.

At the end of December, output was at less than a 10th of the goal, just 2,700 barrels a day. Peak production is now predicted for 2010, 11/2 years late, as Husky pours in $200-million more for drilling and redrilling to rescue Tucker, a project the firm insists is excellent, with a strong reservoir.

Despite the energy boom, $100-plus oil and the promise of huge growth, the oil sands are far more challenging for developers than conventional reserves. And technical challenges and related delays are shaping how the oil sands develop. Enbridge Inc., for example, said this month that these issues have significantly slowed its plan to connect Alberta with Texas by pipeline.

The quickly emerging production method in the oil sands called steam-assisted gravity drainage – SAGD, pronounced sag-D – can be especially tricky, as Husky has discovered at Tucker. Rather than mining bitumen, Husky and others drill wells and inject steam to recover the resource.

“Tucker is a challenge,” Husky chief executive officer John Lau told investors in April during a quarterly earnings conference call.The company has been working for more than a year to fix the problem, rethinking where it drilled its existing wells and drilling new ones.

“We have relooked at our drilling position,” Mr. Lau said.

SAGD is a technology four decades in the making. The general idea was conceived by Roger Butler, an Imperial Oil Ltd. engineer in the late 1960s. In 1978, Imperial drilled one of the world's first horizontal wells to test Mr. Butler's vision. The modest first step was a success. Mr. Butler then took early retirement, working with an Alberta government agency and the University of Calgary to refine the process through the 1980s and 1990s.

It was just seven years ago, in 2001, when EnCana Corp. opened the first commercial SAGD project at Foster Creek, south of Fort McMurray. Now, SAGD has been embraced by the industry as the future of the oil sands, with hometown and global players all putting down big bets, from Calgary-based EnCana Corp. to Britain's BP PLC, Norway's Statoil ASA and Japan Canada Oil Sands Ltd.

In January, the oldest oil sands miner, Suncor Energy Inc., marked a turning point when it said all new production in its planned $21-billion expansion would come from SAGD.

The oil sands are best known for the sprawling mines north of Fort McMurray, where the resource is shallow enough to be stripped away by shovel and truck.However, most of the bitumen in the oil sands lies deeper and cannot be mined. For SAGD, operators drill what are called “well pairs,” two wells that dive several hundred metres into the reservoir and then traverse it horizontally, one well about five metres above the other.

Steam is injected into the top well, warming the glue-like bitumen, which then drips downward – the gravity drainage – where it is collected and carried to the surface by the lower well.

At Tucker, which is near Cold Lake, Alta., several hundred kilometres south of the oil sands mines, Husky originally drilled 32 well pairs to a depth of about 450 metres, with each horizontal well stretching about 700 metres below the surface. The bitumen reservoir is about 40 metres thick and SAGD developers aim their well pairs to ride along the bottom of the reservoir, to get as much oil out as possible.

Husky missed.And even though it was just a near miss, five or 10 metres too deep, it is a costly mistake. The wells were drilled too close to what is called “bottom water.” The injected steam won't properly circulate through the bitumen reservoir because it is being soaked up by an aquifer.

“This is energy exploration,” said Graham White, a Husky spokesman. “The recovery of bitumen, especially with SAGD, is still something that's fairly new. … [And] it can be a matter of metres where you're going to get better production and where you're not.”

In a regulatory filing, Husky said its choice to inject steam at a particularly high pressure looks like a mistake too, with steam being pushed downward and to the side – rather than billowing up into the reservoir.

“Steam likes to move where it can move,” said Richard Gusella, CEO of Connacher Oil and Gas Ltd., a junior oil sands producer that started injecting steam at its 10,000-barrel-a-day Great Divide project last September and is currently reaching predicted production rates.

Heating a reservoir is not easy, Mr. Gusella said, noting that evenly distributing heat along the length of a horizontal well is among the big challenges, trying to hit a narrow mark between 250 and 255 degrees.

“Nothing is ever simple; there are a hundred things you run into, but we're pleased,” Mr. Gusella said. “It's not a perfect world. It's still early days. We're appropriately cautious and careful.”

Husky is redrilling an undisclosed number of the 32 well pairs, has drilled eight new pairs and wants to drill another eight pairs this year.

But while still a young technology, SAGD and future variations will eventually surpass mining in the oil sands. EnCana Corp., in a 50-50 partnership with ConocoPhillips Co. of Houston, aims for 400,000 barrels of bitumen a day, bigger than an existing mine, though those are expanding as well.

Nexen Inc. and partner OPTI Canada Inc. will open a 72,000-barrel-a-day operation this summer and are also aiming for about 400,000 eventually. And while Husky is struggling with Tucker, it is working on a project called Sunrise with BP PLC that could produce 300,000 barrels a day.

Suncor wants to add 272,000 barrels of SAGD to its current SAGD output of 40,000 barrels a day by 2012, transforming the company that opened the first oil sands mine in 1967.

Given that the method is relatively unknown beyond the engineers in Alberta, investors who are wildly bidding up the stock prices of oil sands companies as the price of oil climbs ever higher should be wary, analysts say.

And Husky isn't the only miss. Total SA's SAGD project was supposed to be at 10,000 barrels a day this year. It has not managed to generate commercial production and Total won't reveal the current rate.

“This is still an art form, not a science,” said Justin Bouchard, an analyst at Raymond James in Calgary. “There's lots of things to learn. The technology is in its infancy.”

By David Ebner

What Iran Has

Iran Year:
2002
Energy Production (Quads) = 10.4460 Energy Consumption (Quads) = 5.8775

Oil (Thousand Barrels per Day)




Refinery




Stock



Production
Output
Imports
Exports
Build
Consumption

Crude Oil
3444.30



0.00
2093.60
0.00
0.00

NGL's
86.20


0.00
0.00
0.00
0.00

Other Oils
0.00


0.00
0.00
0.00
0.00

Refinery Gain
-6.53










Gasoline


242.44
65.51
0.00
0.00
296.26

Jet Fuel


17.23
0.00
0.00
0.00
17.23

Kerosene


156.40
0.00
12.39
0.00
144.01

Distillate


452.32
0.00
12.63
0.00
431.81

Residual


449.23
12.00
192.54
0.00
216.34

LPG's


55.55
6.77
0.00
0.00
64.41

Unspecified


120.46
8.00
10.03
0.00
180.28

TOTALS
3523.97
1493.63
92.28
2321.19
0.00
1350.34

Natural Gas (Billion Cubic Feet and Quadrillion Btu)

Gross Production (Billion Cubic Feet) 4273.12
Dry Imports (Billion Cubic Feet) 173.04

Vented and Flared (Billion Cubic Feet) 289.58
Dry Exports (Billion Cubic Feet) 23.66

Reinjected (Billion Cubic Feet) 1059.45

Marketed Production (Billion Cubic Feet) 2924.08

Dry Production (Billion Cubic Feet) 2648.63
Dry Production (Quadrillion Btu) 2.7969

Dry Consumption (Billion Cubic Feet) 2798.01
Dry Consumption (Quadrillion Btu) 2.9547

Coal (Thousand Short Tons and Quadrillion Btu)

Production
Imports
Exports
Stock Build

(1000 Tons)
(Quads) (1000 Tons)
(Quads)
(1000 Tons) (Quads)
(1000 Tons) (Quads)

Hard Coal



720
.0167
25 .0006
0 0.0000

--- Anthracite
0
0.0000









--- Bituminous
1245
.0289









Lignite
0
0.0000 0
0.0000
0 0.0000
0 0.0000

Coke



0
0.0000
0 0.0000
0 0.0000

Total Coal
1245
.0289 720
.0167
25 .0006
0 0.0000

Consumption : (1000 Tons) = 1939
(Quads) =
.0451

Electricity (Million Kilowatts, Billion Kilowatt Hours, and Quadrillion Btu)

Capacity
Generation

(Million kw)
(Billion kwh)
(Quads)
(Billion kwh) (Quads)

Hydroelectric 2.803
7.970
.0811
Total Imports .957
.0033

Nuclear 0.000
0.000
0.0000
Total Exports .799
.0027

Geothermal and Other 0.000
0.000
0.0000
Losses 9.288


Thermal 31.419
124.714


Totals 34.222
132.684
Consumption 123.554