Abstract: A buoyancy module comprises a multi-layer outer protective shell that has an exterior surface and an interior surface. A first layer of foam buoyancy material is located adjacent to the interior surface. A second layer of foam buoyancy material that includes macrospheres and syntactic foam is surrounded by the first layer of foam buoyancy material. The multi-layer outer protective shell can include a layer of fiberglass backed by a fibrous plastic liner. In this embodiment, the layer of fiberglass provides the exterior surface of the multi-layer outer protective shell, while the fibrous plastic liner provides the interior surface of the protective shell. The second layer of foam buoyancy material can be a precast material. The precast material can include for example macrospheres and syntactic foam. The first layer of foam buoyancy material is preferably a stronger layer than the second layer of foam buoyancy material.

Abstract: An insulated pipeline comprises an inner pipe, and an outer poly sleeve co-axial with the inner pipe. The inner pipe and the outer poly sleeve are in spaced relationship to define an annulus. An insulating core within the annulus encases lengthwise the inner pipe, and comprises a plurality of pre-cured syntactic elements. A first binder fills interstices in the annulus. The pre-cured syntactic elements include microspheres and a second binder. Each of the pre-cured syntactic elements may also include macrospheres. The pre-cured syntactic elements preferably extruded and cylindrically shaped. In addition, in one embodiment, the second binder is preferably more rigid than the first binder.

Abstract: A deep sea insulated pipeline comprises an inner pipe which is encased lengthwise by an insulating core. The insulating core comprises macrospheres surrounded by syntactic foam that includes a semi-rigid resin binder and microspheres. The semi-rigid resin binder reinforces the macrospheres to provide sufficient strength to withstand the hydrostatic pressure at depths in excess of several thousand feet of water, and is yet flexible enough to accommodate bending associated with deep sea pipe laying operations. The deep sea insulated pipeline may also include a protective outer casing. The inner pipe extends through and cooperates with the outer casing to define an annulus chamber containing the insulating core. The outer casing may be a plastic pipe. In a preferred embodiment the semi-rigid resin binder includes Bisphenol-A epoxy resin, an anhydride curing agent, and a flexibilizer.