Increasing crude recovery rate by 1% is equivalent to adding seven billion barrels to production, says the head of the department overseeing performance of reservoirs in the National Iranian Oil Company.
"The average rate of recovery from Iran's oilfields is around 20% that is at least 10% less than global standards. In-place oil reserves in Iran are estimated to be in the region of 700 billion barrels, of which 160 billion barrels are recoverable," Karim Zobeidi was quoted as saying at the weekend by the NIOC news portal on Sunday.
Regarding recovery rates in different hydrocarbon fields, he said the figures range between 25% in Aghajari Oilfield [in Khuzestan] and Gachsaran Oilfield in Kohgilouyeh-Boyerahmad Province to 15% in Ahvaz Oilfield in Khuzestan.
Referring to the giant Azadegan Oilfield in Khuzestan near the Iraqi border, Zobeidi said the deposit recovery rate there is as low as 5% because plans to develop the reserve, which included employing the enhanced oil recovery (EOR) and improved oil recovery (IOR) techniques have failed, especially largely due to procrastination of Chinese companies.
Crude oil production from Azadegan Oilfield has seen a dramatic increase after Chinese companies were booted out in 2014 after repeated failures in respecting their contractual obligations, he noted.
"Azadegan's output at180,000 barrels per day, could have risen much higher if Iranian contractors were assigned to the projects earlier."
The field's in-place oil reserve is estimated at 45 billion barrels.
Pointing to South Azadegan production, the official said output has reached 100,000 bpd and work to boost production has gained momentum.
Located 100 km west of the provincial city of Ahvaz, South Azadegan is estimated to hold 33 billion barrels of oil in place. It is part of the West Karoun oil block that holds 67 billion barrels of crude oil.
The field's expansion [with help from local firms] started three years ago and so far 30 domestic companies are involved.
Zobeidi is of the opinion that big new fields are increasingly difficult to discover and thus broader deployment of EOR should be among NIOC's top priorities.
EOR involves injecting fluid into an oil reservoir to boost oil recovery over and above what otherwise would be achieved from pressure maintenance by water or gas injection.
IOR is a term that is sometimes used synonymously with EOR although it also applies to improvement in oil recovery achieved via better engineering and project management, e.g. identifying volumes of oil that have been bypassed during water injection using seismic surveying and then drilling new wells to access those oil pockets.
Zobeidi said the average rate of recovery from hydrocarbon gas liquids reserves in Iran is around 30%.
