PetroChina, the nation's largest oil and gas producer, has developed technology to exploit more than one billion tonnes of oil reserves from its largest and oldest oilfield, Daqing, in Heilongjiang province, but it remains unclear as to whether the advancement would add much to oil output.
The so-called well-fracturing method would help PetroChina drill reserves at Changyuan oilfield, Daqing's major field, reported China National Petroleum Corp (CNPC), the Hong Kong and Shanghai-listed company's parent, in its newsletter China Oil News.
Traditional technology provided access to only 20 per cent of the Category 3 oil-bearing strata, but the new method could significantly increase the ratio, the statement said.
Given the added difficulties with Category 3 oil-bearing strata, these reserves had not been exploited in the past due to technology constraints, the newsletter said.