Oil sand hydrotransport technology has become increasingly important to Syncrude Canada Ltd. and the oil sands industry. Oil sand slurries are complex, multiphase mixtures of bitumen, coarse solids, fine solids, water and air that can exhibit time‐dependent behaviour, wherein pipeline friction losses increase drastically with time. Four separate experimental programs were conducted to study the effect of bitumen on pipeline hydraulics using 100 mm and 250 mm (I.D.) recirculating and once‐through pipeline loops. The results show that pipeline friction losses increase as a bitumen coating forms on the pipe wall. The effect is more pronounced at 50°C, but also occurs at lower temperatures.

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A recent development in the oil sands industry is the hydrotransport of oil sands ore by pipeline from the mine to the extraction plant. Hydrotransport offers economic and technological benefits in mining and extraction operations by eliminating existing bottlenecks, such as conveyors, stackers, tumblers, and screens (McDonell et al., 1995). oil sands ore is transported directly from the crusher to the primary separation vessel without an intermediate tumbler to mix the slurry and condition the ore. It has been demonstrated that an oil sands can be conditioned in a pipeline so that satisfactory recovery of bitumen is achieved at a temperature of 50°C to 60°C. However, as variables such as oil sands grade and residence time change, the operating conditions that will ensure both effic i e n t transport of the slurry and optimal conditioning of the ore need to be known.Good conditioning of an oil sands ore involves two important microscopic processes. First, bitumen is separated from the sand particles as the sand-bitumen interface is displaced by a sand-water interface. Second, the liberated bitumen droplets collide and coalesce with each other and with air bubbles to form larger, more buoyant droplets that are readily separated from the slurry. Droplets that are sufficiently large break up due to shear forces in the fluid. The processes of bitumen liberation and droplet growth and breakup are complex functions of slurry composition, interfacial properties of the constituents, flow conditions, and chemical composition of the water phase. Furthermore, the interfacial properties of the bitumen and the chemical composition of the water phase may vary in time.If the conditioning process occurs during hydrotransport, the state of the dispersed bitumen may influence flow conditions in the pipe. Small droplets are uniformly distributed in the slurry, whereas larger droplets may accumulate at the top of the slurry and adhere to the pipe wall. Given the high viscosity of bitumen, adhesion could result in the creation of a substantial layer of bitumen and consequently an undesirable increase in the pressure required to pump the slurry. Such behaviour was, in fact, o b s e rved by Sanders et al. (2000) in their pilot tests of oil sands hydrotransport. For instance, when a high-grade oil sands slurry was c i rculated through a pipe at 48°C, the pressure gradient increased with time and bitumen accumulated in the upper portion of the pipe. The pipeline friction loss for the slurry was up to three times greater than that of a tailings slurry (i.e., one containing very little bitumen) with a similar * Author to whom correspondence may be addressed. E-mail addre s s : yxu@nrcan.gc.caBench-scale experiments were conducted to study the behaviour of oil sands slurries. While a slurry was being stirred with a standard impeller, the mass of bitumen, M ad , that adhered to a steel probe dipped into the slurry was measured. M ad remained small up to a critical adhesion time, τ ad, and then increased rapidly. τ ad depended on ore grade, t...

The process for extracting bitumen from oil sand has long been a major area for research and development work at Syncrude. Through this work, many new enabling technologies have been developed - the Tailings Oil Recovery (TOR) vessels, the Inclined Plate Settler (IPS), the Naphtha Recovery Unit (NRU), and the Clark Warm Water Extraction (CWWE) process are a few. These developments have resulted in improved naphtha and bitumen recovery, reduced energy costs and improved environmental performance. This paper focuses on another enabling technology in the Extraction area - oil sand hydrotransport. This paper discusses the research and development activities since 1989 that have culminated in the construction and startup of the Extraction Auxiliary Production System (EAPS) in 1993. Learnings from the operation and testing of EAPS have provided important data for the design of hydrotransport - based, bitumen - production systems. These learnings will also serve as a base for development of technology for application on remote lease(s). However, this is not the only new technology required for remote application. This paper will also focus on other new enabling technologies required for off-lease development. Introduction The Extraction Auxiliary Production System (EAPS) (or Plant 24) was constructed in 1993 to demonstrate, at commercial scale, the viability of oil sand hydrotransport technology that had previously been demonstrated on a pilot scale. This commercial scale demonstration was required if hydrotransport was to be considered in the transition to the North Mine. A new hydrotransport system was added to an existing crusher to provide direct slurry feed to the existing primary separation vessels. This bypassed the existing bottlenecks in the mine and extraction areas such as the collection conveyors and stackers, the plant feed conveyors, the tumblers and the screens. The capital for the project was extremely limited and maximum use of existing infrastructure and equipment was required to meet the intended budget of $l2M. P. 625