Overflush
The overflush is the fluid stage of the stimulation treatment cycle that is pumped after pumping the main treatment fluid. Normally a weak acid or brine is used as an overflush fluid. When the main treatment fluid, which is normally a mixture of Hydrofluoric and Hydrochloric or organic acids, comes in contact with the formation, it could produce some byproducts. The objective of overflush is to displace the main treatment acid and also to flush out any byproducts or non-reacted mud chemicals out of the wellbore after the culmination of the treatment cycle.