Abstract: A drilling riser buoyancy module comprises two opposite complementary halves each having complementary co-axially extending central opening for a flow line and at least five complementary axially extending secondary openings for receiving auxiliary lines. Each complementary half comprising foam bounded by an interior surface and an exterior surface. A portion of the interior surfaces of complementary halves contact each another.

Abstract: A flotation device comprises three-dimensional cellular structure comprising a plurality of lengthwise adjacent and radially adjacent hollow cylindrical tubes, wherein interstices between the plurality of cylinders are filled with a composite matrix of macrospheres and syntactic foam.

Abstract: A length of buoyant, flexible insulating material for lengthwise encasing a length of pipe comprises syntactic foam that includes a thermoset resin binder and microspheres, wherein the syntactic foam encases a plurality of substantially parallel longitudinal fibrous strands. The thermoset resin may comprise an epoxy resin that includes Bisphenol-A, a curing agent, and a flexibilizer.

Abstract: A macrosphere comprises a multilayered spherical wall that includes (i) a first wall that includes a first epoxy and first fibers (ii) a second wall that includes a second epoxy and second fibers and (iii) a third wall that includes a third epoxy and glass micro spheres, wherein the third wall is located between the first and second walls and the multilayered spherical wall forms a hollow chamber. The fibers may be carbon fibers. However, it is contemplated that glass fibers may also be used rather than carbon fibers. In addition, it is contemplated that the first layer may be formed using glass fibers, while the second layer is formed using carbon fibers.

Abstract: A method of manufacturing syntactic foam comprises mixing a non-liquid amine adduct and a liquid epoxy to form a matrix. Hollow microspheres are added to the mixture and mixed together to form a mixture, which may then be poured into a mold and heated to form a molded syntactic foam component.