L. Li, Y. Xi, M. Hubler, J. Nemecek
University of Colorado at Boulder,
Keywords: nanoparticles, injection technique, wellbore, well cement
Summary:Well cement has been commonly used in the underground constructions, such as oil wells for oil and gas extraction and sealing wellbore in CO2 storage formation. For the safety of long-term operation of the wellbores, leakages in wellbore cement must be sealed. Nanoparticles in various slurries can be used to seal cracks in well cement. This study investigated the feasibility to use an electrochemical method to inject nanoparticles into well cement not only to repair wellbore leakages and initial defects but also to extract the harmful ions (e.g. chlorides) simultaneously. Various experimental parameters were studied including different surface charges, types and sizes of nanoparticles and the intensity of injecting power supply. The penetration depths of the nanoparticles were evaluated by different techniques for porosity of well cement. The purpose of the study was to develop a new injection technology that can be used for repairing the leakage of well cement for the oil and gas industry as well as for CO2 storage formations.