Abstract: In the view of the well bore blockage issue in Dina-2 gas field，according to the chemical composition of well head foreign matter and well bore blockage，it was considered that the well bore blockage had three sources which were formation sand，crystal of carbonate scale under certain environment and organic matter. This paper summarized the unplugging measures experience of tubing perforation，plugging removal of coiled tubing，and replacement of pipe column and cleaning pitshaft. According to the actual situation of long opening thickness，non- full diameter pipe column，far distance between well bore block site and perforation bottom，this paper analyzed the feasibility of chemical solution such as plugging removal of acidization；it is considered that the acidization is a better solution at present.

Key words: Dina gas field, pitshaft, blockage, chemical deplugging