Abstract: Implementations described and claimed herein provide systems and methods for breaking cement within an annulus of a wellbore. In one implementation, an annulus cement breaking system includes a cement compression tool operable to be disposed within an inner bore of a casing having a longitudinal length. The casing is disposed within a wellbore formed in a subterranean formation having a cement layer disposed within an annulus formed between the casing and the subterranean formation. One or more actuation elements are coupled with the cement compression tool, and the one or more actuation elements are operable to engage the inner bore. The one or more actuation elements are transitionable between an unactuated state and an actuated stated. The actuated state operable to engage the inner bore of the casing, thereby radially expanding the casing and compressing the cement layer.

Abstract: The present invention relates to an anti-fouling coating composition that comprises a marine biocide and a binder which is a hydrolyzable film-forming seawater-erodible polymer. The polymer contains sulphonic acid groups in quaternary ammonium salt form.

Abstract: A boat hull or part thereof produced by applying layers of curable resin to a mould or former and curing the resin in the mould or on the former. A layer of a non-biocidal antifouling material is applied to the mould, or to the outermost layer of resin if using a former, so that the non-biocidal antifouling material forms the outermost layer of the boat hull. A non-biocidal antifouling material used as the outermost underwater surface of a boat hull has fine grooves extending in the longitudinal direction of the hull. The grooves can be formed by applying the non-biocidal antifouling material to a grooved mould when using the process described above. Alternatively the underwater surface of a boat hull can be clad with a grooved non-biocidal antifouling material.

Abstract: A marine surface having a coating comprising a silicone rubber-silicone oil mixture produced by cold-curing an oligomeric silicone rubber having hydroxyl end groups in the presence of a silicone oil. The coating acts as an anti-fouling composition to prevent or reduce accumulation of organisms such as barnacles, algae and the like on the marine surface during prolonged exposure to sea-water.

Abstract: A top coat paint for ships' hulls comprisinga. a film-forming copolymer containing from more than 50 up to 80 per cent by weight of units of at least one tri-organo tin salt of an olefinically unsaturated carboxylic acid, the balance of the copolymer being units of at least one olefinically unsaturated comonomer,B. a substantially water insoluble metalliferous pigment capable of reacting with sea-water to form a water-soluble metal compound, andC. a hydrophobic organic retarder for retarding the rate of ion exchange between sea-water and the copolymer (a), which retarderI. has a solubility in sea-water at 25.degree. C. of not more than 5 parts per million by weight and is miscible with the copolymer (a),Ii. has a negligible vapour pressure at 25.degree. C. andIii. is present to the extent of at least 5 per cent by weight based on the weight of the tri-organo tin ion content of the copolymer (a).