Malaysia is Southeast Asia's second-largest oil producer behind Indonesia. Petroleum and other liquids production (including crude oil, lease condensates, natural gas liquids, biofuels, and refinery processing gains) in 2013 was nearly 670,000 barrels per day (bbl/d), hovering around the same level since 2011 and down from the country's peak production of 844,000 bbl/d in 2003. More than a fourth of Malaysian oil production currently originates from the Tapis field in the offshore Malay Basin. The country's oil production has experienced overall decline as a result of maturing fields, particularly larger fields in the shallow waters offshore Peninsular Malaysia. Some recent drilling efforts in the area such as Lundin Petroleum's Bertam oilfield in the Penyu Basin are expected to offset some production declines from mature fields.