Development and Performance Evaluation of Shale Self-Absorption Hydration Inhibitor

To control the hydration of shale due to high hydrophilicity and capillary self-absorption effect,laboratory research on self-absorption hydration of shale was carried out.A self-absorption hydration control agent (FZXJ) was developed by means of the proportional optimization with complex synergism of various surfactants as well as comparative evaluation on the rock surface dripping and soaking effect.The results indicated that the developed agent had a contact angle of 78.8°,remarkably reduced water amount absorbed on shale surface to 0,kept the rock sample in whole and possessed good compatibility with polymer drilling fluid.Characterized by fabulous amphipathic property and absorption preference,the agent could actively prevent the self-absorption effect of shale and lower water absorption before the formation of mud cake.Acting synergetically with shale inhibitor and blocking agent,it can improve wellbore stability.In a word,the agent had a promising application effect in oilfields.