EFFECT OF ASPECT RATIO ON PRESSURE LOSS AND CHARACTERISTICS OF LOW REYNOLDS NUMBER FLOW THROUGH NARROW SLOTS
In steam assisted gravity drainage (SAGD), bitumen flows through slots whose width is selected based on the particle size of the formation sand to prevent sand production. These slots are susceptible to several failure mechanisms such as plugging, scaling, and fouling. Given the flow optimization that should also be achieved, understanding the phenomenon of flow through these slots is essential. This coupled problem of sand control and flow optimization can be solved if only effects of the slot properties are known and
described comprehensively. This study investigates the significance of longer slots in achieving desired
flow conditions. The effects of aspect ratio (the ratio of the orifice axial length to the aperture size) of a
rectangular orifice on the flow of a highly viscous fluid (dynamic viscosity, μ = 110 mPa.s at 45 °C) at low Reynolds numbers (Re < 1) is studied. The rectangular shape is selected to represent the slots in slotted liners well completions that are used in SAGD applications. Experiments are performed using different size orifices made on coupons and are located inside a pipe. Aspect ratios (AR) within the range of 1 ≤ AR ≤ 75
are used at different flow rates while keeping Reynolds numbers constant. The results show that increasing
aspect ratio leads to increase in both static and non-dimensional pressure drops. The wide range of aspect
ratio covered is a unique aspect of the present study when compared to the literature that gave the same definition to the parameter.