Introduction
Some crude oils react with acid to form a black asphaltic sludge by the coagulation of unstable colloidal material in the oil. The sludge is a mixture of asphaltic compounds, resins, paraffins and other high-molecular weight constituents of crude oil. Sludge can stabilize emulsions, cause plugging of pore spaces and may be responsible for the poor performance of matrix treatments in some reservoirs.
Anti-Sludging Agent is used in acid fluids to control acid sludging problems during matrix treatments. It is also a good emulsion-preventing agent to be used to prevent emulsions caused by acid mixing with the produced oil.
Physical Properties and Hazards

Chemical Properties and Application
Anti-Sludging Agent
is a good surface-active agent for low pH systems. It provides low-surface tension properties to matrix treatment fluids and water-wets sandstone and limestone formations. Anti-Sludging Agent
functions by stabilizing the colloidal asphaltic material in the oil and preventing the contact of cationic counter ions of the acid (H
+
), iron (Fe
3+
) and/or calcium (Ca
2+
) with the colloid.
Anti-Sludging Agent
is also effective in preventing and breaking emulsions due to its unique chemical nature.
Anti-Sludging Agent
is compatible with most additives in stimulation fluid systems. It is also readily biodegradable and presents lower toxicity to organisms than other surface-active agents.