In recent year, deep water drilling has become to go deeper area. It is not only oil and gas exploration, but also Methane Hydrate exploration and scientific drilling. In general, deep water drilling has a greater degree of difficulty than conventional drilling. Drilling fluid design issues include Shallow Water and Gas Flow (SWF, SGF), Narrow Operation Window, Gas Hydrates, Low Flow System Temperature and High Pressure situation, etc. Especially, shallow water/gas flow, gas hydrates, low temperature and high pressure situation are much related for drilling fluid. Drilling fluid design allow choice of Water Based Mud (WBM) and Oil or Synthetic Based Mud (OBM, SBM). Both systems had have solutions for conventional drilling so far. Not every ultra deep water well will present all of the issues wrote above, but many of them will be presented. Currently, solutions of SWF/SGF are using weighted mud, Remotely Operated Vehicle (ROV) and Annular Pressure While Drilling (APWD). WBM use Thermo Dynamic system to inhibit gas hydrates. However, it is needed that research and development of low dosage inhibitor as Kinetic Hydrate Inhibitor (KI) and Anti-Agglomerant (AA), toward much deeper.