Abstract: A new type of well completion fluid system had been developed in order to prevent reservoir damage caused by the leakage of working liquid in the process of gas storage well completion.High water absorbing material which can absorb water dozens to hundreds times its own weight,was used to control the free water in the well completion fluid system.The water absorption ability,water retention,and thermal stability of strong water absorption materials were evaluated and selected;the performance of strong water absorption temporary plugging system was evaluated,too.The results showed that the system had a good temporary plugging performance,temporary plugging pressure could reach more than 20 MPa,and gas reverse breakthrough pressure was less than 1 MPa.Field application showed that when 8 m3 perforating fluid was injected into the formation after perforation,followed by 2 m3 well killing fluid,no serious leakage occurred,effectively preventing the leakage of working liquid.Strong water absorption temporary plugging technology provided technical guidance for completion of similar low pressure and medium permeability reservoirs.