Petroleum industry has been more and more concerned about the effects of produced water disposal in the environment, particularly in offshore fields. Increasing amounts of produced water have being processed by companies and the search to alternatives for the produced water destination has become a priority for the major operators.
As oilfields reach their maturity, the water cut increases, and Produced Water Re-Injection (PWRI) in the producing formation seems to be a convenient way for its destination. Disposal in adjacent, non-oil bearing formations is also an attractive option to be considered.
This paper presents an overview of the main PWRI projects in Petrobras. Petrobras has been re-injecting water in their mature onshore fields for many years, and it is starting re-injection projects in offshore Campos Basin.
Technical, economical and environmental aspects of PWRI are presented. Related topics, like injectivity loss due to PWRI, injection above the fracture propagation pressure, PWRI effects on oil recovery and reservoir souring potential are discussed.