Preparation and Evaluation of Thermosensitive Plugging MaterialsBased on Shape Memory Polymers

Considering the insufficient ability of traditional plugging materials to seal fractured leakage, shape memory polymers (SMPs) were introduced for plugging. A thermosensitive plugging material was prepared based on SMPs for their “temperature-controlled deformation” property. Then, its glass transition temperature and shape memory performance were evaluated by the thermo-mechanical dynamic analyzer and shape recovery test. Moreover, the simulation tests of fracture plugging were carried out to assess the plugging capability of the polymers on fractures and explore the plugging mechanism. The research results indicated that the deformation temperature(glass transition temperature) of the thermosensitive plugging material could be regulated in the range of 80–120 ℃ according to the locations of the leakage layers, featuring excellent shape memorizing performance (with a shape recovery ratio of more than 95%). In addition, the temperature resistance of this material was good, with the initial pyrolysis temperature between 230 and 258 ℃, which meant that the material could be applied in a formation temperature environment of 80–120 ℃. The compound of this material and the traditional plugging material could successfully seal the fractures with width ranging from 3–5 mm. The research results can provide a reference for the preparation and application of this new material to fracture plugging.