INTRODUCTION
•Production of water is usually associated with the production of crude oil and natural gas
•The produced water may be water that exists within the petroleum reservoir as connate
water
or bottom water.
•Water-flooding operations, water is injected into reservoir to
enhance the recovery
Produced and treated water quality
•Produced water always has to be treated before it is disposed or injected into the
reservoir.
•The purpose of the treatment is to remove enough oil from the water such that the
remaining amount of oil is the water and the oil droplet size are appropriate for the
disposal or injection of the water.
Produced Water Treating Technology
•Suspended Solids Removal
•Suspended Oil Removal
•Chemical Treating for Control of Bacteria
•Chemical Treating for the Control of Scale
•Corrosion Control Techniques
•Other Chemical Treatment Needs
Suspended Solids Removal
•suspended solids have a tendency to plug the injection formation thereby tending to
cause the produced water injection pressure to increase and the produced water
injection flow rate to decrease.
•Suspended solids that are present in the water will exist as distinct particles of varying
sizes and densities dispersed throughout the water phase.
•Particles that are heavier than water will tend to drop to the bottom of the pipe,
vessel or other type of container at various rates.
•Stoke’s Law describes the vertical velocity at which a particle falls through a liquid
phase.
Stoke’s Law
•Where :
•Δρ = difference in density of the dispersed particle
and the continuous phase,
•g =“g-force” acceleration factor,
•gc = gravity acceleration constant,
•dp = dispersed particle diameter, and
•μL = viscosity of the continuous phase.
it is clear that the settling velocity can be increased by:
1. Increasing the size of the solid particles (i.e. by using chemical agents), or
2. Increasing the difference in density between the oil droplet and the water phase, or
3. Lowering viscosity of the water (i.e. by operating at the highest possible temperature), or
4. Increasing the “g-force” imposed on the fluid (i.e. by centrifugal motion)