Intensified concerns about hazardous environmental effects of conventional oil-based mud (OBM) in Iranian offshore oil fields and limited offshore performance of water-based mud (WBM) motivated drilling companies in Iran to search for a suitable substitution. Synthetic based mud (SBM) is a relatively new class of drilling fluids that can combine technical advantages of OBM and WBM. This book presents a feasibility study of utilizing innovative formulations of synthetic paraffin-based mud in Iranian oil fields. Suitable formulations for SBM are developed for operational ranges of temperature, mud weight and synthetic water ratio (S/W). In addition, rheological properties and electrical stability of the systems are measured. Stability of each mud system under down-hole conditions is examined. The obtained results for SBM are compared with similar conventional oil based packages. Experimental results show that from technical point of view, conventional muds can be replaced with paraffin-based mud in Iranian offshore fields since it suppresses environmental concerns and provides advantages of WBM and OBM with reasonable cost.