Though 2012 was less than stellar for many resource companies, some that posted some notable gains. Here is a list of the top 10 TSX Venture Exchange-listed oil and gas juniors.1. Emperor Oil (TSXV:EM); current price: $0.41; year-to-date gain: 561.54 percent; 52-week high: $0.62. Emperor Oil is an oil and gas exploration company with projects in Turkey and Sudan. On September 23, Emperor signed a memorandum of understanding (MOU) with State Petroleum Overseas that enabled it to acquire 85 percent of a 50-percent working interest in a late-stage oil project in Block 7 in Sudan. The Block 7 concession is 10,000 square kilometers and through the MOU, Emperor intends to develop three discovered oil fields. The company also announced a non-brokered private placement of up to 40,000,000 units at a price of $0.50 per unit for gross proceeds of up to $20 million. In late October, Emperor announced that it had received subscriptions for roughly 30,000,000 units — a gross total of approximately $12 million. 2. Africa Oil (TSXV:AOI); current price: $6.75; year-to-date gain: 323.42 percent; 52-week high: $11.35. Africa Oil is a Canadian oil and gas exploration company with assets in Kenya, Ethiopia, Mali and Puntland (Somalia). The company is exploring in the East African Rift Basin and has both operated and non-operated blocks, with an under-explored proven petroleum system. Last week, Africa Oil closed the final tranche of its $232.5-million private placement announced in late November. Proceeds from the transaction are being used to fund Africa Oil's ongoing work program. Africa Oil announced several new oil discoveries this year, starting with the Ngamia-1 well in Kenya, where the company encountered over 20 meters of net oil pay in March. More recently, in November, Africa Oil announced a second significant Kenyan oil discovery at the Twiga South-1 well, where it encountered 30 meters of net oil play in the tertiary sandstone reservoirs.