Abstract: Heavy oil well blockage occurs frequently in dilution exploration process in TAHE oilfield, which influences the production seriously. The SARA analysis of the blockage indicates that about 57% of it is asphaltene. This work investigates, based on the analysis, the solubility properties of the plug in different mediums and develops a new composite blockage removing and inhibiting agent RPDA-02. Its saturation solubility for the blockage is up to 2.0 g/g, much higher than the reference agents. The blockage inhibition performance of RPDA-02 shows that the inhibition time for asphaltene deposition is more than 60 days. The field test shows that temperature changes have little impact on the performance of RPDA-02. A continuous agent injection process is developed based on the conditions of the oilfield, which can well solve the problem of blocking and has no undesired effect on the subsequent processing of produced liquid.