Injecting gas into oil reservoirs should be given priority over gas export to revive unused reserves, a former oil minister said.
Mohammad Gharazi added that after supplying towns and villages with natural gas, the most important priority is to increase extraction from oilfields by injecting gas into oil reserves that have not been exploited for a long time, ILNA reported.
The official noted that oil extraction rate is normally 40% in the world but the maximum exploitation rate for Iranian oilfields stands at 15%, therefore implementing enhanced oil recovery methods seems to be inevitable.
Enhanced oil recovery—aka EOR—is the implementation of various techniques for increasing extraction from an oilfield.
Gharazi noted that in order to increase domestic oil production, officials ought to revive massive oilfields such as Ahvaz, Gachsaran or the abandoned Haftkel Oilfield located in Khuzestan Province in southern Iran.
Referring to the exploitation of Haftkel reserves during the 1930s and 40s by the British, he noted that the reservoir is dead, as water has blended with oil. Thus, instead of exporting gas, we need to “inject it into reservoirs to guarantee production security at least for 100 years”, he said.
According to the former oil minister, Masjed Soleiman Oilfield in Khuzestan used to produce 40,000 barrels of crude per day. However, it has declined to 5000, which can be restored again after gas is injected into it.
Criticizing the lack of research projects conducted on oilfields, he said, “There are more than 100 oil reserves in Iran, which have just been exploited after discovery, yet they have never been studied scientifically. Otherwise, the exploitation rate would have risen to 70%.”
Highlighting the fact that the pound per square inch pressure—aka PSI—in Ahvaz reservoir has decreased to 1000 PSI from 2000 PSI in 40 years, Gharazi emphasized that the only way to boost production from such fields is to implement EOR in addition to gas injection.