Abstract: A method and apparatus for detecting compositional aspects such as sand, water, wax deposits or asphaltene deposits of a fluid in a petroleum pipeline is disclosed. A method for managing flow of a fluid in a petroleum pipeline is also disclosed. X-rays are transmitted through the petroleum pipeline and detected to generate a density gradient profile which is preferably a function of time and space. Characteristics of the density gradient profile and correlated with characteristics of the compositional aspects of interest. The method and apparatus preferably provides presence and relative amount of the compositional aspects in real-time or near real-time such that corrective action can be taken is such aspects are not in acceptable ranges.