Synatic foam design modifications

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. Each exterior surface of the two halves comprises (i) a first flat exterior surface segment radially opposite an associated first flat exterior surface segment of the other half, (ii) a second flat exterior surface segment radially opposite an associated second flat exterior surface segment of the other half, where the second flat exterior surface segment is circumferentially adjacent to the first flat exterior surface segment and (iii) a plurality of partially-cylindrical exterior surface segments whose aggregate circumferential length is greater than aggregate length of the first and second flat exterior surface segments of the two opposite detachable complementary halves.

What is claimed is: 
     
         1 . A drilling riser buoyancy module comprising:
 two opposite detachable complementary halves each having a complementary co-axially extending primary central opening for a main flow line and first and second complementary axially extending secondary openings radially adjacent and on opposite sides of the primary central opening for receiving and holding first and second auxiliary lines respectively, each opposite detachable complementary half comprising syntactic foam bounded by an interior surface and an exterior surface, where a first of the opposite detachable complementary halves includes a third co-axial auxiliary line opening and a second of the opposite detachable complementary halves includes a fourth co-axial auxiliary line opening and a fifth co-axial auxiliary line opening;   where a portion of the interior surfaces of complementary halves are configured and arranged to contact each another, and   where each exterior surface of the two opposite detachable complementary halves comprises (i) a first flat exterior surface segment radially opposite an associated first flat exterior surface segment of the other half, (ii) a second flat exterior surface segment radially opposite an associated second flat exterior surface segment of the other half, where the second flat exterior surface segment is peripherally adjacent to the first flat exterior surface segment and (iii) a plurality of partially-cylindrical exterior surface segments whose aggregate circumferential length is greater than aggregate length of the first and second flat exterior surface segments of the two opposite detachable complementary halves.   
     
     
         2 . The drilling riser buoyancy module of  claim 1 , where the plurality of complementary axially extending secondary openings are substantially semi-cylindrical. 
     
     
         3 . The drilling riser buoyancy module of  claim 1 , where a first of the two opposite detachable complementary halves includes a first axial opening formed in the interior surface of the first of the two opposite detachable complementary halves. 
     
     
         4 . The drilling riser buoyancy module of  claim 2 , where a second of the two opposite detachable complementary halves includes a second axial opening formed in the interior surface of the second of the two opposite detachable complementary halves and a third axial opening formed in the interior surface of the second of the two opposite detachable complementary halves. 
     
     
         5 . A drilling riser buoyancy module comprising:
 two opposite detachable complementary halves each having complementary co-axially extending primary central opening for a main flow line and at least five complementary axially extending secondary openings for receiving and holding auxiliary lines, each opposite detachable complementary half comprising foam bounded by an interior surface and an exterior surface,   where a portion of the interior surfaces of complementary halves are configured and arranged to contact each another, and   where each exterior surface of the two halves comprises (i) a first flat exterior surface segment radially opposite an associated first flat exterior surface segment of the other half, (ii) a second flat exterior surface segment radially opposite an associated second flat exterior surface segment of the other half, where the second flat exterior surface segment is circumferentially adjacent to the first flat exterior surface segment and (iii) a plurality of partially-cylindrical exterior surface segments whose aggregate circumferential length is greater than aggregate length of the first and second flat exterior surface segments of the two opposite detachable complementary halves.