Apr. 2012 - OGX has completed the drilling of the second appraisal well, OGX-81, at the Tambora field. The operator found 203 feet (62 meters) of net pay in the Albian section and 20 feet (6 meters) in the Eocene section.

Jul. 2011 - OGX has encountered hydrocarbons in the Santonian and Albian sections of well 1-OGX-52-RJS (Tambora) in the BM-C-41 block, in the shallow waters of the Campos Basin. OGX said this discovery near the Waimea accumulation successfully tested Albian calcarenties in a deeper position, completely independent of the prior discovery. The well found a hydrocarbon column of about 39 feet (12 meters) in the sandstone reservoirs of the Santonian section with about 16 feet (5 meters) of net pay. Additionally, the well also found a hydrocarbon column of nearly 571 feet (174 meters) in carbonates of the Albian section with about 315 feet (96 meters) of net pay. The Ocean Ambassador semisub performed the drilling operations. Tambora lies in Block BM-C-41 about 60 miles (96 kilometers) off the coast of the state Rio de Janerio in a water depth of about 427 feet (130 meters). OGX wholly owns and operates the block.