The world petroleum industry shows a decreasing in the oil reserves, specially the light kind. For this reason is very important to implement process schemes that give the possibility to improve the recuperation of valuable products of heavy oil. In this case the bottom processing in each one of the petroleum refining stages earns great importance with the purpose of maximizing the quantity of fuel by barrel of raw processed. Therefore, it has been proposed the modification of the currently vacuum residues process scheme in the Ecopetrol`s Barrancabermeja refinery (DEMEX-Visbreaking-Hydroprocessing). That modification consists in the incorporation of an additional Visbreaking stage, previous at DEMEX extraction stage.
 This investigation was developed with plant pilot tests combined with statistical models that predict the yield and the quality of the products obtained in the industrial plants. These models were developed by the Instituto Colombiano de Petróleo (ICP).
 The modified scheme Visbreaking I-DEMEX- Visbreaking II- Hydroprocessing, gives the possibility to increase the yield of middle distillates. Besides decrease the quantity of demetalized oil produced in DEMEX stage. This reduction is very favorable since environmental point of view, because it allows have a percentage of free capacity in the Hydroprocessing unit in order to removed sulfur of valuable products like Diesel and in this way to respect the environment law to this kind of fuel.