Nanoparticles and polymers complexes as a harmless shale plugging inhibitor for ocean water-based drilling fluids

Due to the stringent environmental regulations that have been gradually proposed, the additives of WBDFs with low toxicity and degradability have become crucial. Clays and nano-micron fractures are the main causes of wellbore instability in ocean shale formations. In this paper, the plugging inhibitor was designed based on the skeletal structure of molecule, functional groups and molecular weight. Then the silane coupling agent was used to modify silica nanoparticles. And further the ZY-1 as a harmless plugging inhibitor was created by graft copolymerization of transition product and AA-AAK. These evaluation results demonstrated that ZY-1 not only was nontoxic and biodegradable, but also displayed a decent thermal stability (150 °C) and plugging inhibitive performance. What's more, this paper proposed the underlying inhibition and plugging mechanisms based on the structure and function of ZY-1.