An understanding of the behaviour of wet crude oil in pipelines is important to the selection of, not only the appropriate pipeline size, but also of downstream equipment. Does the mixture flow as a true emulsion, or a liquid-in-liquid dispersion? As important as this subject is, little is known about it. There have been very limited published works on it.
In this book, I present an approach to the problem. The thrust of this approach is a development of new, theoretical concepts to align with observed realities. A few new terminologies are introduced. An existing widely-held notion is challenged - the notion that an oil/water mixture is either emulsified or not emulsified.
The overall objective of the book is to present an algorithm which can be incorporated in hydraulic analysis of pipeline systems, to take care of the behaviour of oil/water mixtures. Adoption of the algorithm should lead to more realistic predictions of pipeline pressure profiles.
Raphael Sunday Awoseyin December 1995
| A | = pipe cross-sectional area, sq. m |
| Ap | = surface area of liquid droplet, sq. m |
| d | = pipe internal diameter, m |
| dp | = liquid droplet diameter, m |
| D | = geometrical diameter of centrifugal pump impeller, m |
| Ei | = emulsification index |
| fn | = Fanning friction factor |
| gc | = gravitational conversion factor, 4.18 (108) (lb. mass) (ft.)/(lb. force) hr.2 |
| H | = liquid head, m |
| L, l | = pipe length, m |
| n | = number of pump impellers |
| N | = rotational speed, rpm |
| NRE | = Reynolds number |
| Pemul | = energy for emulsion |
| Pshear | = energy for shearing |
| q | = volume flow rate, m3/s |
| Q | = liquid flow rate, m3/s |
| u | = droplet velocity, m/s |
| U | = average flow velocity, m/s |
| α | = emulsion viscosity constant |
| ε | = pipe internal surface roughness, m |
| φ | = water cut |
| ρ | = fluid density, kg/m3 |
| Δp | = pressure drop, Pa |
| Δpf | = pressure drop due to friction, Pa |
| μ | = dynamic viscosity, Pa.s |
| η, η' | = efficiency |
| ω | = rotational speed, rad/s |
| Subscripts | |
| e | = emulsion |
| o | = oil |
| w | = water |
| d | = dispersed phase, or droplet (depending on context) |
| cont | = continuous |
| disp | = dispersed |