Cleanup of filter cake is a difficult task and becomes more challenging when dealing with weighting materials such as manganese tetraoxide. Mn3O4 is a strong oxidizing agent and can be used as a catalyst due to its active phase, which will result in complex interactions with most cleaning fluids.

The reaction of selected organic acids and chelating agents with Mn3O4 particles as a function of time and temperature were studied. Atomic absorption was used to measure manganese concentrations and X-ray diffraction to analyze solids remaining after the reaction.

White precipitate of manganese citrate was produced following the reaction of citric acid with Mn3O4 up to temperatures of 284°F. The amount of precipitation increased with temperature and initial chelate concentration. GLDA reacted with Mn3O4 particles completely at 190°F. However, a large amount of white precipitation produced. Similarly, a white precipitation was observed with oxalic and tartaric acids. The reaction of DTPA with Mn3O4 particles in glass reactor produced Mn(silicates) at 212 and 284°F. This study will help drilling/completion engineers to avoid using such chemicals to prevent formation damage after filter cake removal treatments.

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