During hydrocarbons extraction from reservoir a big amount of water is produced. The volume of water does not remain constant over time, but the percentage increase passing the time. The presence of water enlarges the hydrocarbons production costs since it decrease the productivity capacity of the wells, increasing the treatments complexity of hydrocarbons. The water treatment is a delicate issue in the oil industry, both from economical and environmental point of view. In the last years eni has developed different R&D projects for optimizing the water treatment processes and for improving the quality of the water. The produced water, once treated, can be reinjected into the reservoir or discharged in surface (sea, rivers, desert). The use of innovative technologies both onshore and offshore has allowed the discharge of water into surface bodies with oil in water concentration less than country regulations where the reservoir is placed. This paper presents an ongoing project concerning the application of a produced water treatment system in the Raml field (Western Desert) in order to improve quality of the produced water, reaching the required target for the reinjection (oil-in-water ≤ 10 ppm and total suspended solids ≤ 15 ppm) also minimizing operations management and equipments maintenance. A testing campaign on the deoling system, part of the water treatment system, was done on January 2010. This paper reports the processand scheme developed and the positive results obtained during this trial.