Elaboration of mending additives for the cement sheath repair

Abstract

The dynamic loads and internal stresses applied onto a well during its operation period, gradually leads to deterioration of the cement sheath that usually exists behind the casings. Such mechanical and chemical exposure causes the cement to develop severe cracks that enables cross feeds behind casings and uncontrollable flow between formations leading to oil-gas mixture and migration of hydrocarbons into freshwater aquifers causing immediate harm to local water sources [1], affecting the zonation capability of the cement itself behind the casings.
 This issue has been in the industry of oil and gas for ages, leading us to investigate the possibility of maintaining the integrity of the cement stone behind the casings through the principle of self-healing materials, through this principle a self-healing cement was formulated adding secret agents into the ordinary cement powder which will be able to cure cracks in the cement stone under special conditions without human intervention. This can be an effective measure for loss of well integrity prophylaxis and eliminates well shutdowns for well workover operations.