Composition useful in sulfate scale removal
The present invention discloses a novel aqueous composition for use in removing petroleum-contaminated barium sulfate scale from a surface contaminated with such, said composition comprising: a chelating agent and a counterion component selected from the group consisting of: Li 5 DTPA; Na 5 DTPA; K 5 DTPA; Cs 5 DTPA; Na 4 EDTA; K 4 EDTA; TEAH 4 DTPA; and TBAH 5 DTPA; a scale removal enhancer; and a non-ionic surfactant. There is also disclosed methods to use such compositions.
1. An aqueous composition for use in removing petroleum-contaminated barium sulfate scale from a surface contaminated with such, said composition consisting of:
a chelating agent having chelating agent components, said chelating agent components including Ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), Tetraethylammonium hydroxide (TEAR), and Tetrabutylammonium hydroxide (TBAH)
said chelating agent and a counterion component selected from the group consisting of: Na 5 DTPA; K 5 DTPA; Cs 5 DTPA; Na 4 EDTA; K 4 EDTA; TEAH 4 DTPA; and TBAH 5 DTPA;
a scale removal enhancer;
a non-ionic surfactant;
distilled water;
potassium hydroxide; and
wherein the non-ionic surfactant is a linear alcohol ethoxylate surfactant having a chain length of at least 6 carbon atoms and wherein said aqueous composition has a pH ranging from 10 to 11.
2. The aqueous composition according to claim 1 , wherein the scale removal enhancer is selected from the group consisting of: potassium carbonate; potassium formate; cesium formate and cesium carbonate and combinations thereof.
3. The aqueous composition according to claim 1 where the non-ionic surfactant is a linear alcohol ethoxylate surfactant selected from the group consisting of: alcohol ethoxylate surfactants having a chain length of at least 8 carbon atoms.
4. The aqueous composition according to claim 1 where the non-ionic surfactant is an alcohol ethoxylate surfactant selected from the group consisting of: alcohol ethoxylate surfactants having a minimum degree of ethoxylation of 9 or higher.
5. The aqueous composition according to claim 1 where the non-ionic surfactant is an alcohol ethoxylate surfactant selected from the group consisting of: alcohol ethoxylate surfactants having a HLB value of 13 or higher.
6. The aqueous composition according to claim 1 , wherein the scale removal enhancer is present in the composition in an amount ranging from 5 to 20 wt % of the composition.
7. The aqueous composition according to claim 1 , wherein the scale removal enhancer is present in the composition in an amount ranging from 10 to 15 wt % of the composition.
8. The aqueous composition according to claim 1 , wherein the scale removal enhancer is present in the composition in an amount of approximately 10 wt % of the composition.
9. The aqueous composition according to claim 1 , wherein the chelating agent and counterion are present in the composition in an amount ranging from 5 to 40 wt % of the composition.
10. The aqueous composition according to claim 1 , wherein the chelating agent and counterion are present in the composition in an amount ranging from 10 to 30 wt % of the composition.
11. The aqueous composition according to claim 1 , wherein the chelating agent and counterion are present in the composition in an amount ranging from 10 to 20 wt % of the composition.
12. The aqueous composition according to claim 1 , wherein the scale removal enhancer is selected from the group consisting of: K 2 CO 3 ; KOOCH; CsCO 3 ; CsCOOH.