Discussion on the Application of Super-Absorbent Polymer in Gas Drilling to Dry Wellbore

In gas drilling,formation water flow may lead to instability of water-sensitive mudstone and shale.To solve this problem,the feasibility of applying super-absorbent polymer(SAP)to dry wellbore was investigated.A laboratory experiment was made to evaluate the absorption capacity,absorption velocity,salt resistance,temperature resistance,compressive strength,pH value adaptability,modification methods,ability of passing through bit nozzle,recycling and reuse of such materials.The results indicate that super-absorbent materials provide strong and fast water absorption,the absorption capacity is less sensitive to temperature and pressure and highly sensitive to salt content,which can be improved by modification methods.The SAM can return to the surface successfully after absorbing water and then recycled. However,they can’t be reused because of difficult dehydration.It is suggested that super-absorbent materials are feasible in both materials and technology for drying wellbore.This research provides new ideas and methods for wellbore drying in gas drilling.