Pipe inclination effects on high viscosity oil-gas two phase flow characteristics

There is a growing interest in the exploration of high viscous unconventional reserves attributable to its huge reserves amidst an increasing decline in low viscous conventional reserves. In this paper, the effects of upward pipe inclination and liquid viscosity on two phase flow characteristics have been carried out experimentally in a 0.0256m ID pipe inclined at an angle of 15°. Air and mineral oil were used as test fluid with oil viscosities ranging from 0.7-5.0 Pa.s. The superficial velocities of gas and liquid velocities were varied respectively from 0.3 to 10 m/s and 0.06 to 0.3 m/s. Electrical tomographic capacitance sensor readings and visual observations revealed four flow patterns. Two phase characteristics measured include pressure gradient, liquid holdup, and slug flow features, i.e. slug frequency and slug liquid holdup. Analysis of the pressure gradient exhibited a gradual increase with increasing superficial gas velocity at a constant superficial liquid velocity which steeped when the superficial liquid velocity was increased. A similar trend was observed for pressure gradient as the angle of inclination is increased.