MOSCOW, May 15. /TASS/. Rosneft Vietnam B.V. (a subsidiary of Russian state oil company Rosneft) has started drilling a production well at the Lan Do field in the offshore zone of Vietnam, the oil company said in a statement.

"Target depth of the well is about 1,200 m along the well bore, sea depth at the drilling site is around 160 meters. As estimated Lan Do field has initial natural gas reserves of 23 billion cubic meters," according to the statement.

This year, Rosneft also plans to perform sidetracking of previously drilled PLD-1P exploration well on Phong Lan Dai field (Wild Orchid) which is also located within Block 06.1.

Target depth of the well is 1300 meters. As a result the well will be reclassified as a production well.

Wild Orchid field revealed commercial gas reserves of 3,4 billion cubic meters, according to the statement.