Material for Zonal Isolation of Shallow Formation: State-of-the-art and Development of Alternative Material

Abstract

Shallow depth cementing remains a challenge in well construction due to its unique characteristic of low temperature and low formation pressure. Potential flow zones such as shallow gas and shallow water flow increase difficulty in ensuring proper zonal isolation. This study is divided into two phases including the evaluation of existing zonal isolation materials and the development of new alternative materials. In the first phase, this study examines various commercially available barrier materials used in cementing operations of shallow formation Norwegian Continental Shelf. These materials include neat G cement, industrial rapid hardening cement, gas tight cement, and geopolymer. Their performance was evaluated under equal conditions to assess their effectiveness. The second phase covers further development of low-density geopolymer for shallow depth cementing. Two approaches are used including a water-extended system and the use of glass bubbles as lowdensity filler. The outcome of each study includes performances of each material and newly developed material, which are under review and published in seven papers: four scientific journals, and three technical conferences. Paper I and II reveal the state-of-the-art of various cementitious materials for shallow depth cementing such as Neat G cement, rapid hardening cement, and gas tight cement. Moreover, these studies present its limitations and shortcomings at low temperatures. Paper III considers the in-depth rheology of various cementitious materials and comparing to gas-tight cement behavior which has been proven to be able to mitigate shallow gas migration. Paper IV, V presents the gained knowledge in low-density granite-based geopolymer through water-extended approaches by optimizing precursor particle size distribution and selection on different slags. Paper VI reveals the role of lime (CaO) in the early strength Development of low-density granite-based geopolymer. Different reactivity of lime obtained from different calcination temperatures was used. Paper VII presents the development of a low-density granite-based geopolymer using glass bubbles and observes its impact on rheology and strength development.