The ultimate goal of cementing is to provide well integrity through zonal isolation during well construction process. As chemistry being one of the main disciplines contributing to the development of several new technologies to achieve long term well integrity in oil and gas wells, several case histories will be discussed in this section. This section will present the application of low-carbon geopolymer based cement free system offshore, epoxy-based sealant injection, seal-healing cement and cementitious swell packer to address sustained casing pressure. The session will also discuss wellbore shielding spacer and industry proven tool for cement placement as lost circulation mitigation measures. Additionally study of rock physical and mechanical properties and use engineered slurry system to prevent cross-flow will also be reviewed in this session.