Successful hydrocarbon production in the San Jorge Basin in Argentina is achieved with understanding the high variations in reservoir fluid properties, discriminating the complex lithology, and achieving the optimum hydraulic fractures. This paper outlines how state of the art logging tools and collaboration between the operating and service companies can deliver improved fracture results.
The multi-layered stratigraphic formations in the San Jorge Basin have long presented formation evaluation challenges with conventional well logging. These formations exhibit major inconsistencies and anomalous results in formation water salinity. In addition, the complex reservoir characteristics have required the use of hydraulic fracturing to improve the hydrocarbon production during the past fifteen years.
Nowadays, petrophysical evaluation of the reservoirs has been improved using the latest well logging technology such as Nuclear Magnetic Resonance (NMR) logs to identify and distinguish potential productive layers and zones to be stimulated.
Combining NMR logging technology with fracture height evaluation utilizing azimuthal shear wave slowness data, stimulation treatment pressure responses, and post-stimulation swab test results, provides sufficient data to calibrate geomechanical and hydraulic fracturing models. With advanced interpretation techniques and modeling, the optimum fracture can be designed and performance data from that fracture can be used to validate the theoretical models. This approach enhances the capability to design hydraulic fractures based on the reservoir conditions, with the optimum conductivity and fracture half-length to provide the required productivity over the life of the well.
Application of this process has resulted in improved well performance in the San Jorge Basin wells. The integration and interpretation of information between the operator and the service companies resulted in more accurate and optimized work flows and modeling for the complex and non-conventional reservoirs of the San Jorge Basin. As companies work together in a collaborative environment to address business challenges, solutions have been generated that no single company could have achieved alone.