Transcripción del resumen del autor. El Trapial Field is located in the Neuquén basin near the Andes Mountains, in the western part of Argentina, South America. The primary reservoirs are Lower Cretaceous continental and shallow marine sandstone, with porosities of 18% and average permeability of approximately 75mD. This 1.2 B bbl OOIP oil field was discovered in 1991, and water injection commenced in 1994. In 2005 a multidisciplinary team, was empowered to find new drilling opportunities with focus on two main objectives: Enhance the Base Business and monetize the P2 and P3 reserve base. In February of 2006, the first appraisal well ETa-756 was drilled in an area originally interpreted as water bearing, based on known O/W contacts and a seismic low area. After confirming an oil leg existed, this new block, called Porche I, became a small green field development next to the mature El Trapial oilfield, producing at 88% water cut. During the development of Porche I, a step-out appraisal drilling campaign was carried out and the OWC was defined in this initial block (Porche I). Later, new 3D seismic was recorded and a full delineation appraisal drilling campaign fully defined the block, greatly extending the discovery towards the East and South West of the initial block. An integrated development plan resulted from the application of a Uncertainties Management Plan, robust appraisal program, GOCAD, CHEARS and Decision Analysis models. Challenging rules of thumb for pattern spacing, configuration and processing factor, have resulted in a more efficient development outcome compared to historical ET field development. Together, the sequential development of the defined Porche area, represents more than 60% of the El Trapial field current oil production, and contributes more than 60 MM bbls of proved reserves.