A process and apparatus for creating a controlled environment about a portion of a submerged pile to be treated comprises a jacket fitted about the pile and sealed at both the top and bottom ends relative to the pile to provide a sealed encapsulated space. The jacket includes at least two sections having arcuate cross sections that are fastened together to provide a substantially cylindrical jacket. Compressed air is forced downward into the encapsulated space through one or more upper valves and encapsulated water is forced out through one or more lower valves. Further air flow dries the encapsulated space. Desired coatings, for example, rust inhibitors, epoxies, are introduced into the encapsulated space through the lower valve and the displaced air, excess coatings and chemical by-products are vented and recovered for disposal through the upper valve. The temperature inside the encapsulated space is also controlled.

An offshore well is stabilized by at least three cables connected on one end to hydraulically powered cable tensions on the well casing at a location substantially below the surface of the body of water in which the well is located and on an opposite end to a respective anchor pile on the bottom body of water. The cables are equally tensioned by the hydraulically powered cylinder and are subsequently retained in taut condition by mechanical retainers.

An improved grouting method and arrangement using particulate material and aqueous solutions of alkali silicate materials confined between pile seal assembly and top of an offshore platform in sealing the annular space formed between either a jacket leg or pile sleeve and a pile driven therethrough or similar annular space of an offshore platform to support a column of grout thereon so that the annular space may ultimately be filled with grouting material.

A method and apparatus for constructing a underground barrier wall structure using a jet grout injector subassembly comprising a pair of primary nozzles and a plurality of secondary nozzles, the secondary nozzles having a smaller diameter than the primary nozzles, for injecting grout in directions other than the primary direction, which creates a barrier wall panel having a substantially uniform wall thickess. This invention addresses the problem of the weak "bow-tie" shape that is formed during conventional jet injection when using only a pair of primary nozzles. The improvement is accomplished by using at least four secondary nozzles, of smaller diameter, located on both sides of the primary nozzles. These additional secondary nozzles spray grout or permeable reactive materials in other directions optimized to fill in the thin regions of the bow-tie shape. The result is a panel with increased strength and substantially uniform wall thickness.

The present invention relates to subterranean cementing operations and, more particularly, to cement composition that include improved lost circulation materials, and methods of using such cement compositions in subterranean formations. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an generator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.