Commercial production of gas from the Songo Songo Island field in the Indian Ocean commenced in 2004, thirty years after it was discovered there. Over 35 billion cubic feet of gas was produced from this field in 2013, with proven, probable, and possible reserves totalling 1.1 trillion cubic feet. The gas is transported by pipeline to Dar es Salaam. As of 27 August 2014, TANESCO owed the operator of this field, Orca Exploration Group Inc.