All oil that is produced spends some time in a pipeline. A pipeline is the most inexpensive method of transport available, however, the high initial investment demands a long term commitment. A pipeline can begin at a wellsite (where it is usually called a "flowline") or at a battery, and then goes through various transitions before it reaches a refinery. The stages employed in the Lloydminster region can be identified as: the producing well, transport to a battery (by truck or flowline), the Battery (the cleaning and treating process), a Feeder Pipeline (such as the Husky Pipeline), and the Major Trunklines (for example, Enbridge and Express).
The life expectancy of a well, the volume it produces, and the well’s distance from the battery dictates whether the oil is flowlined or trucked to the battery. The cleanliness of the oil is not an important concern unless it will compromise the flow, however, corrosion caused by saltwater is a problem.
Oil, whether pipelined or trucked to the battery, can be more than 50% saltwater and can include some sand. At the battery it is cleaned to less than .5% S & W (sediment and water). Treated oil is taken from the battery’s sales tanks by a booster pump, and transferred through a Lease Automatic Custody Transfer (LACT) station. The LACT system monitors the cleanliness of the product and meters the transferred volume. Oil that does not meet specifications can be sent back to the battery for further cleaning. The booster pump also provides head pressure for the shipping pump which brings the oil up to pipeline pressure. Condensate can be added at any place in the system before the shipping pump, taking advantage of the lower pressures. A series of check valves prevents the higher system pressures from pushing the oil back into batteries.
Husky Oil operates a large gathering system in the Lloydminster region which collects oil from as far away as the Cold Lake fields in the north and Turtleford in the east. This gathering system culminates at the Lloydminster Pipeline Terminal and from there is distributed to the Husky refinery, the upgrader, and the pipeline to Hardisty. Husky Synthetic Blend (HSB) produced by the Upgrader is also handled by the pipeline system. The Lloydminster pipeline terminal has several tanks with total a capacity of 1,000,000 barrels. The three basic products stored in these tanks are: Lloyd Blend crude which is approximately 20% diluent (condensate), Husky Synthetic Blend produced by the Upgrader, and diluent (a term which includes condensate and closely related thinning materials). Diluent is pipelined in from the Hardisty terminal and also is recycled from the oil processed by the refinery and upgrader. The entire Husky pipeline system is controlled remotely at the Lloydminster Terminal by an SCADA computer monitoring system.
Husky sends its Lloydminster output through another section of pipeline to the Hardisty terminal which also has a 1,000,000 barrel tank capacity. Husky owns this section as well and it consists of four lines which branch into five at Wainwright. Husky has dedicated each of these lines to a specific purpose. One handles diluent coming from Hardisty, two transport HSB, and one carries Lloyd Blend. The additional line from Wainwright to Hardisty handles that areas output (Wainwright Blend).
Husky uses positive displacement screw type pumps driven by 500-1000 horsepower electric motors, and centrifugal pumps driven by 600 or 2500 hp electric motors. The Husky Mainline (from Lloydminster to Hardisty) can move up to 1000 m3/hr of Lloyd Blend, 600 m3/hr of HSB, 150 m3/hr of Condensate, and 180 m3/hr of Wainwright Blend. The system operates at licensed pressures up to 1440 psi. Production is tanked at Husky’s Hardisty terminal before it is sent down the trunklines. The trunkline transports all types of crude through the same pipes, however, these different products command different prices and must not be mixed. Unlike Husky’s pipeline where turbulence is not desired, turbulence is used to maintain separation of products in the mainline.
Pipeline cleaning is accomplished through flushing and the use of cleaning "pigs." A cleaning pig has cup seals which make it act like a hydraulic piston and it is pushed along the pipe by product while scrubbers scrape the sides of the pipe. "Pigs" cannot go through a pump and must be installed and removed between them at special junctions in the pipeline called "pig traps".
Pipelines are closely monitored and controlled by increasingly sophisticated electronic and computerized equipment. They move high volumes of crudes, safely and efficiently to often distant markets.