Japan's state-affiliated Japanese Oil, Gas and Metals National Corporation (JOGMEC) on Tuesday started the seismic acquisition operation for oil and gas exploration in Cambodia's Preah Vihear province, said a government official.

Phay Siphan, spokesman for the Council of Ministers, said the JOGMEC would drill 6,000 holes, each has a 6-milimeter diameter and up to a depth of 20 meters for the four-month seismic survey in the province.

Preah Vihear province, situated some 500 kilometers northwest of Phnom Penh, is home to more than 200 ancient temples including Preah Vihear temple, one of the world heritage sites.

Ho Vichit, vice-chairman of Cambodian National Petroleum Authority, said the seismic acquisition operation is one of the first steps of oil and gas exploration study and the operation will not have any impact on the environment and natural cultural sites.

"The start of the seismic survey in block 17 reflects foreign trust on Cambodia's investment environment and it is a new success for Cambodia towards the development of oil and gas sector," he said in a speech during the launching of the seismic study in the province's Tbeng Meanchey district on Tuesday.

JOGMEC and Cambodian National Petroleum Authority signed the Basic Agreement for the Study and Survey Program in Block 17 onshore Cambodia in May 2010.

The Block 17 onshore oil field covers a total area of 6,500 square kilometers of hilly forest in Kampong Thom, Preah Vihear and Siem Reap provinces, said Phay Siphan.

Last month, China National Offshore Oil Corporation (CNOOC) announced that drilling of the first well started in the Block F offshore in Cambodia's Preah Sihanouk province.

The impoverished Southeast Asian nation hopes that the first drop of its own-produced oil will be available by December, 2012 as Cambodia's Petrochemical Company, a joint-venture with China National Automation Control System Corporation, has been studying the feasibility to build an oil refinery with an annual capacity of 5 million tons in Preah Sihanouk province.