The breakup of the monopoly of crude oil exploration in Brazil has led to the need for a better assessment of measurement instruments. Brazil, which recently announced massive oil finds -the largest discovery in the West Hemisphere in the last three decades-, requires better national metrology infrastructure. The objective of this M.Sc. dissertation is to characterize qualified demands for basic metrology services. And its motivation stems from a new bill (Portaria Conjunta ANP-INMETRO) that prompted research and development programmes in the realm of metrology and gave rise to a new culture of measurement in Brazil. The research work was carried out in the context of a sharp increase in oil demand -particularly from India and China- in recent years. High oil prices driven by rising demand now call for measuring devices with low level of measurement uncertainty and greater accuracy. The methodology used included: (i) the analysis of oil and gas exploration environment in Brazil, (ii) the study of applicable legislation and (iii) the application of international best practices in flow measurement. Relevant metrology demands were identified -this was the major result of the research project- based on Petrobras`s own experience, notably from its Business Unit in the Campos Basin, in the state of Rio de Janeiro. The work suggest a procedure to identify the various types of measuring schemes and meters most adequate for the oil industry and contributes to a better understanding of the applicable legislation. In addition, it helps Petrobras to balance supply and demand for metrology services. As a conclusion, the work highlights the vulnerability of metrology in the sector.