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)