What is teh best practical way to deal with FeS issues in the existing produced water treatment systems. Certain reservoirs turns sour producing lot of H2S and starts getting mixed with Iron already present in the produced fluid resulting in the production of FeS.
The FeS produced can become neutraly bouyant when coated with oil and genarets lot of issues in the gas flotation and media filters units in the existing PW treatment systems.
What are the options available to deal with this issue. I.e mechnaical and chemical.
If chemical, what type pf chemical is better for dealing this issue i.e. adding oxidation chemicals to drop the iron, adding Chelating chemicals to keep the iron in the solution etc.
If mechnical, any new technology that can treat the produced water to its required specification and still deals with the FeS despoit. Or is there retrofit options available to be implemented in the existing gas flotation and media filter units.
Please sugegst a process scheme for a PW treatment system to meet oil in water (
Hydrochloric acid can be used to dissolve iron sulohide that contain iron and sulfur at a molar ratio close to unity. Non-acid formula can be used to remove iron sulfide scale, however, their ability to dissolve iron sulfide depends on the molar ratio of iron to sulfide. To prevent the formation of iron sulfide, squeeze treatments to the formation were found to be very effective
Thank you very much for sharing your opinion.
you are right that squeeze treatment is very effective for bottom hole to reduce sulphide scaling. We now see lot of interest from operators in teh middle east to deal with the FeS deposit blocking surface equipment. FeS getting coated with oil makes it even worse.
Not sure if acid treatment is suitabe for surface water piping esp when we deal with 100k barrels of water or more which is typical. please share you experience more on surface treatment of oil coated FeS. in particular, if possible.
H2S in water poses a big water treatment problem. Possibly you need to combine chemical and physical method. You initially apply oxidants such as oxygen, chlorine, chlorine dioxide, hydrogen peroxide, ozone and potassium permangate which eventually and unfortunately will lead to the formation of polysulfides and other metal complexation which can be physically removed after coagulation or floccuation. Generally iron complex removal much be treated on case specificity because you have also to consider NOM as well as pH. So try a combination of different methods.
Thank you very much for your insight Gift. HIghly appreciate your time.
Not sure if activated carbon is the right solution to remove oil coated iron sulphide particles as the sole reaosn for raising this topic is here is that even proven Wallnut filters fails dramatically when they experience oil coated FeS particles in their system.
Personal exprience carrying out onsite analysis on FeS indicates that there is no readymade available that can be considered as "one size fit for all".
Detailed study on the water chemistry and staibility mechanism of FeS is significant whilst deciding the type of treatment required i.e chelating, dissolving FeS using chemicals or physical separation of FeS after it has been formed etc.
Presence of nasty components such as Ashpaltenes vary the impact of FeS significantly.
More holistic approach would be required whilst delaing with FeS to operate the Pro. Water treatment system more effective and efficiently.
Regards
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Coating