T'^r^mf 



Figure 1. Simplified diagram of hypothetical fixed drilling platform, showing 

 possible sound pathways from source points: diesel engine or 

 turbine, drill platform, and drill bit. Possible paths include: 

 structure-borne, air-borne, drill string and casing-borne, 

 ground-borne, and water-borne sound. 



G-^^. 



