Produced Water Treatment

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)