Netherland, Sewell and Associates (NSAI) have independently re-certified an unrisked prospective resource of up to 910 MMBBL and 3,105 BCF gas (464 MMBBL oil and 1,583 BCF gas* to Petrel’s 51% net interest). The update to the initial January 2015 resource certification by NSAI integrates recent amplitude versus offset (AVO) analysis of seismic data from the 2014 597 kilometre 2D seismic acquisition programme. AVO anomalies particularly at the top of structural highs may represent the presence of gas-filled sandstone reservoirs. Following additional interpretation of the seismic data one of the 20 conventional structural leads, Lead B, identified on the first pass in January 2015, has been upgraded to the first prospect in Salto by NSAI and the SEI technical team. The gross resource potential of this prospect ranges from 10.7MMBBL (P90) to 65.0MMBBL (P10). Further analysis and interpretation of the geological structure in Salto has also identified an additional older sedimentary sequence that is not included in the updated conventional Prospective Resource estimates. These older sediments could contain additional hydrocarbon potential. While the updated prospective oil and gas resource estimate is slightly lower in barrel of oil equivalent terms (BOE), the possible presence of gas and AVO’s significantly increases the certainty of our gas resource estimates. The presence of gas not only represents play type diversity, but also provides additional lift mechanisms for the oil volumes. Given both the oil and gas targets are at relatively shallow depths across large areas of both permits, wells are likely to be relatively inexpensive to drill and complete. It should also be noted that although this is a very encouraging Prospective Resource certification, the estimates are based on a limited 597 line kilometre seismic programme within our extensive 14,000km2 (3.5m acres) permit areas. The seismic results are a satisfying conclusion to what has been a very successful exploration programme which has not only confirmed the existence of an active and previously unknown hydrocarbon system but also significant conventional resource potential. SEI (51% PRL) as a consequence is in an enviable position to begin considering potential partners to assist with the next stage of exploration and appraisal of Uruguay’s largest onshore concession.