New Wellbore-Integrity Classification for Gas Migration Problems and New Cement Formulations Using Graphene Nano Platelets to Prevent Gas Migration through Cemen

Gas migration, one of the primary problems related to the integrity of oil wells, is caused by cement failures. Gas migration can result in costly well repairs and may endanger personal, equipment, and result in severe operational difficulties and environmental issues. The ultimate objectives of this research were to provide a comprehensive review of the problem and to provide a solution to the problem using Graphene Nano Platelets (GNPs).;An intensive review was performed to understand the cement failures. The reasons behind these failures were analyzed and classified with respect to their locations in the wellbore. Recommendations and potential solutions for these problems were also suggested. A new classification was established and would work as a roadmap to understand the oil well cement failures and would help prevent their occurrence.;An intensive laboratory work was conducted to better understand the cement and the cement testing methodologies. In addition, GNPs were added to the cement to enhance its properties. The evaluation of the neat cement and the new cement formulations included testing their mineralogy by implementing X-ray diffraction (XRD) analysis, testing the mechanical properties of the set cement, testing the stability and rheology of the liquid slurry, and evaluating the chemical shrinkage of the cement. In addition, the effects of adding GNPs on the hydration process of the cement was studied using isothermal calorimeter. The findings of this investigation showed that GNPs played a key role in regulating the microstructure of the hydration products of the cement, which enhanced the toughness of the cement without affecting its stability and flow-ability. The GNPs also aided in controlling the propagation of micro cracks within the cement matrix.