Study and evaluation on deep-penetrating acid used for removal of mud pollution in Block W588

In Block Wang 588, drilling mud pollution is mainly caused by solid-phase invasion and noncompatibility of filtrate with formation water.Through optimization, a new surfactant DS-101 acid mixed system has been developed, which is a kind of highly efficient deep-penetrating acid, with high solid phase dissolving capability.Experiment results indicate that this system is stable under high temperature conditions.It has not only strong sludge dispersion and dissolution ability, but also an obvious plugging removal effect of mud contamination.Core testing shows that the core permeability recovery rate can reach up to 127% with this acid.