Cleanup of filter cake is a difficult task and becomes more challenging when dealing with weighting materials [e g, manganese tetraoxide (Mn3O4)]. Mn3O4 is a strong oxidizing agent and can be used as a catalyst because of its active phase, a nonstoichiometric Mn3O4 composed of an octahedral Mn2O3 phase and a tetrahedral MnO 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 was studied. Solubility and compatibility tests of Mn3O4 particles with cleaning fluids were conducted using a high-pressure/high-temperature (HP/HT) see-through cell. Reaction kinetic tests were conducted using a three-neck round-bottom flask. Atomic absorption was used to measure manganese concentration, and X-ray diffraction was used to analyze solids remaining after the reaction. A white precipitate of manganese citrate was produced following the reaction of citric acid with Mn3O4 up to 284 degrees F. The amount of precipitate was increased with temperature and initial acid concentration. An amino polycarboxylic acid chelating agent derived from L-glutamic acid (GLDA) (a chelant) reacted with Mn3O4 particles completely at 190 degrees F. However, a large amount of a white was precipitate produced. Similarly, a white precipitate was observed with oxalic and tartaric acids. The reaction of diethylene triamine pentaacetic acide (DTPA) (a chelate) with Mn3O4 particles in a glass reactor produced Mn (silicates) at 212 and 284 degrees F. The results of the present study will help drilling/completion engineers avoid using such cleaning fluids to prevent formation damage after filter-cake-removal treatments.