Peculiarities of hydrodynamics of pumps for the extraction of high-viscosity oil

Special features of the offshore fields currently under development are the high production rate of wells (~104 bpd) and the high viscosity of the produced water-oil emulsion ~102-103 сP, depending on the water cut. There are no special pumps designed for these conditions, so the production is carried out by the traditional centrifugal pumps suitable for the low-viscosity applications. For the selection purpose their testing on benches is performed according to the methods adopted in the oil industry at a frequency of up to 58 Hz (3500 rpm). The only difference is that instead of the traditional low-viscosity working fluid (water) high-viscosity Newtonian fluids (such as glycerin and oil) are used. Such tests only approximately correspond to well conditions; the following factors are not taken into account: the change in the properties of the liquid along the pump, the increase in the energy efficiency of pumps at increased shaft speeds, and, finally, the non-Newtonian rheology of the extracted emulsions...