Research and development of anti-high pressure sealing material and sealing characteristics in hydraulic fracturing borehole

In order to solve the downhole field application problem of hydraulic fracturing technology which is restricted by the difficulty of sealing holes, in this paper, on the basis of summarizing the existing hole sealing materials and sealing methods at home and abroad, through a large number of basic experiments, the influence of auxiliary materials such as ordinary cement added with special composite cement, swelling agent and water reducing agent on the basic properties of anti-high pressure sealing materials such as setting time, fluidity, compressive strength and swelling multiplication rate was studied. The best water-cement ratio of 0.5, 20%-25% of special composite cement, 4% of compound expander and 1.6% of naphthalene water reducer were determined to ensure the early strength and high strength of the anti-high-pressure sealing material with the premise of flowability and expansion rate. It also conducted on-site industrial experiments in Pinggang Coal Mine of Longmei Coal Group, and its parameters such as solidification time and compressive strength met the performance requirements.