Disclosed is a sealing apparatus for use in establishing a seal around a tubular, and a method of use of the sealing apparatus. The apparatus includes a deployable sealing arrangement which can be engaged with an internal wall of a tubular so as to form a sealed area. The wall of the tubular may then be perforated within the sealed area, and sealant injected through the perforation. Accordingly, the apparatus permits both perforation and sealant injection to occur within a common sealed area, assisting to ensure that the injected sealant will always be appropriately aligned with the established perforation, thus maximizing the injected volume of available sealant. Isolation of the sealed area from fluid inside the tubular also prevents or restricts contamination of the inside of the tubular with sealant or fluids around the tubular, and sealant cannot be washed away by fluid within the tubular.