Scaling problem is common in oilfield due to high concentration of salts in produced water and pressure temperature variations. It can be minimized and control by using scale inhibitors. In case of scale formation, it can be cleaned by using proper scale dissolvers (commonly acid, water or chelating agents).

For proper scale dissolver job, it is necessary to know the nature and solubility of scales that are to be removed. Some easy tips are used to analyses scale for cleaning purpose. It is;

  1. - Check its solubility for water, Weiher it is water soluble salts (Cl) based.
  2. - Check its solubility for acid(HCl,)Weither it is acid soluble i.e CO3 based.
  3. - Check its solubility for Organic Solvent, Weither it is Organic soluble.
  4. - You can check it solubility for Hydrogen Florid (HF) if it is not soluble in the above. It will tell you if it is Silicate based.

After the above initial physical tests, proced it for %age of the given salts, by determination of the major component i.e Na, Ca, Mg, Sr, Fe via AAS or Titrametric, colorimetric and gravimetric methods.

  • In case of Step 01 above, report it as NaCl, CaCl2, MgCl2 and SrCl2.
  • In case of Step 02, report it as Na2CO3 CaCO3, MgCO3, SrCO3 and FeO3.
  • In case of Step 02 and Step 03, report it as Organic Solvable.
  • In case of Step 03, report it as Silicates.

In the light of the above tests, you can recommend the washing solvent for its cleaning purpose.

Scale %age Composition Analysis: For the of %age composition determination, analyze the scale for Na, Ca, Mg, Sr, Fe, SO4 and Carbonate (Titrometrically or Via AAS). In the light of the above physical test calculate in term of %age as per above step 01 & 02. The detail composition analysis can help us in the determination of the source of scaling, so we can control it by proper treatment accordingly. --Wali Ullah Khan 21:22, 13 June 2013 (PDT)