Estimation of Mature Water Flooding Performance and Optimization by Using Capacitance Resistive Model and Fractional Flow Model by Layer

Waterflooding is the oldest and most extended method to enhance recovery from oil reservoirs in primary production with low natural energy in the Golfo San Jorge Basin, Argentina. Water injection has proven to be an effective method to enhance recovery from oil reservoirs for project CM-123-A at Cañadón Minerales field, Golfo San Jorge Basin. Defining the optimized injection rates and injection patterns, which depend on the geological structure of the reservoir, is an essential operational and economical decision for reservoir management. In this paper, the capacitance resistive model (CRM), which takes into account implicitly the geological and reservoir parameters, is used to find inter-well connectivity by layer (independent reservoir), optimize injection rates with the complement of net sand maps and petro-physical and production test data, and check the consistency of the solutions with all the available data to support the decisions. The CRM receives the injection rates variations as input signal, from the different reservoirs, whereas the producer responses determine the injector/producer pair connectivity quantitatively. The different runs of the CRM can be used to detect how some abrupt changes in the artificial lift of the producers affect the connectivity and propose some improvements. Also, this model is used to predict gross production for individual reservoir, together with a multilayer FFM (fractional flow model) can be estimated the oil production for each individual reservoir, identify the potential from different reservoirs and improvements in the injection rates to optimize the oil production. The results reveal that the CRM has the capability to match the production history to calibrate the dynamical effective parameters and with this characterization optimize the injection rates of the different wells injectors and reservoirs, during the immiscible flooding, understand water injection movement, and as accessory the joint validation of the net sand maps. The CRM was able to detect inter-well connectivity for producers connected not only at the first line but also at the second line, with a clear response in the field.