Dilbit is diluted bitumen. Per the Alberta Oil Sands Bitumen Valuation Methodology, "Dilbit Blends" means "Blends made from heavy crudes and/or bitumens and a diluent usually condensate, for the purpose of meeting pipeline viscosity and density specifications, where the density of the diluent included in the blend is less than 800 kg/m3." If the diluent density is greater than or equal to 800 kg/m3, the diluent is typically synthetic crude and accordingly the blend is called synbit.

Why dilute bitumen?

Bitumen and heavy oils

Heavy crude oil

Heavy crude oil or extra heavy crude oil is any type of crude oil which does not flow easily. It is referred to as "heavy" because its density or specific gravity is higher than that of light crude oil. Heavy crude oil has been defined as any liquid petroleum with an API gravity less than 20°.Extra...

 are often produced from remote deposits such as the Athabasca oil sands

Athabasca Oil Sands

The Athabasca oil sands are large deposits of bitumen, or extremely heavy crude oil, located in northeastern Alberta, Canada - roughly centred on the boomtown of Fort McMurray...

 in Alberta

Alberta

Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 and the Orinoco tar sands in Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

. Before 1980, most produced bitumen was transported by truck, but trucking is seasonally restricted and relatively inefficient and expensive compared to pipeline transport

Pipeline transport

Pipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....

. However, bitumen in its undiluted state is too viscous

Viscosity

Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...

 and dense

Density

The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 to be transported by pipeline. To create a fluid capable of transportation by pipeline, bitumen must be mixed with a fluid that has much lower viscosity and will keep bitumen from precipitating

Precipitation (chemistry)

Precipitation is the formation of a solid in a solution or inside anothersolid during a chemical reaction or by diffusion in a solid. When the reaction occurs in a liquid, the solid formed is called the precipitate, or when compacted by a centrifuge, a pellet. The liquid remaining above the solid...

 out of the mixture. By 1985 and demonstrating the effectiveness of dilbit, Alberta Energy Company was operating dual pipelines to transport diluent from Edmonton to Cold Lake

Cold Lake oil sands

The Cold Lake oil sands are a large deposit of oil sands located near Cold Lake, Alberta.Cold Lake is east of Alberta's capital, Edmonton, near Alberta's border with Saskatchewan, and a small portion of the Cold Lake field lies in Saskatchewan.In 1980 a plant in Cold Lake was one of just two oil...

 and dilbit from Cold Lake to Edmonton.

How is bitumen diluted?

The most common diluent used to dilute bitumen is natural gas condensate

Natural gas condensate

Natural-gas condensate is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields....

 (NGC), especially the naptha component. Due to insufficient quantity of natural gas condensate, bitumen shippers also use refined naptha and synthetic crude oil

Synthetic crude

Synthetic crude is the output from a bitumen/extra heavy oil upgrader facility used in connection with oil sand production. It may also refer to shale oil, an output from an oil shale pyrolysis. The properties of the synthetic crude depend on the processes used in the upgrading. Typically, it is...

 (SCO) as diluent. Although SCO requires a higher volume percentage to achieve the same viscosity, at least one study found that SCO provides better blend stability than NGC. Shippers dilute bitumen before shipment in order to meet viscosity and density requirements found in common carrier

Common carrier

A common carrier in common-law countries is a person or company that transports goods or people for any person or company and that is responsible for any possible loss of the goods during transport...

 pipeline tariff rules. By selecting different diluent types and blend ratios, bitumen shippers attempt to lower component costs, increase blend value, and maintain pipeline transportability. The blend ratio may consist of 25 to 55% diluent by volume, depending on characteristics of the bitumen and diluent, pipeline specifications, operating conditions, and refinery requirements.

What happens to the dilbit?

Diluent can be removed from dilbit by distillation and reused as diluent. Alternatively, the entire dilbit can be refined. As dilbit contains hydrocarbons at extreme ends of the viscosity range, dilbit can be more difficult to process than typical crude oil. As such, dilbit is normally only a small portion of a refinery's total feedstock.

Alternatives to diluent

• Heated pipelines
• Constructing upgraders
  Upgrader
  An upgrader is a facility that upgrades bitumen into synthetic crude oil. Upgrader plants are typically located close to oil sands production, for example, the Athabasca oil sands in Alberta, Canada or the Orinoco tar sands in Venezuela....
  
   closer to production

See also

• Canadian Centre for Energy Information
  Canadian Centre for Energy Information
  The Canadian Centre for Energy Information is a non-profit organization created in 2002 to meet an urgent need for information on all aspects of the Canadian energy system from oil, natural gas, coal, thermal, and hydroelectric power through to nuclear, solar, wind, and other sources of energy...
  
  
• Dilbert
  Dilbert
  Dilbert is an American comic strip written and drawn by Scott Adams. First published on April 16, 1989, Dilbert is known for its satirical office humor about a white-collar, micromanaged office featuring the engineer Dilbert as the title character...
  
  
• Drill bit
  Drill bit
  Drill bits are cutting tools used to create cylindrical holes. Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes....
  
  
• History of the petroleum industry in Canada (oil sands and heavy oil)
  History of the petroleum industry in Canada (oil sands and heavy oil)
  Canada's oil sands and heavy oil resources are among the world's great petroleum deposits. They include the vast oil sands of northern Alberta, and the heavy oil reservoirs that surround the small city of Lloydminster, which sits on the border between Alberta and Saskatchewan...
  
  
• Syncrude
  Syncrude
  Syncrude Canada Ltd. is the world's largest producer of synthetic crude oil from oil sands and the largest single source producer in Canada. It is located just outside Fort McMurray in the Athabasca Oil Sands, and has a nameplate capacity of of oil, equivalent to about 13% of Canada's consumption...
  
  
• Suncor

External Links

• Southern Lights Diluent Pipeline