Rheology of petroleum sludge is important from the standpoint of transportation and handling. Heavy crudes may contain significant amounts of high molecular weight materials such as asphaltenes and resins. The molecular weight of asphaltene may range between 1.000 and 2.000.000, and they serve as the major constitutent of petroleum sludge. The formation and accumulation of petroleum sludge have significant implications on utilization and processing of heavy crudes. The objective of this study is to evaluate the rheology of petroleum sludge and compare the results with that of biological sludge. Techniques have been developed to dramatically improve the transportation properties of petroleum and sewage sludge.