Bangestan Reservoir, Potential Investment Project
Iran has pinned its hopes for bringing its oil production to more than 5 mb/d under its Vision plan 2020 on enhancing recovery from ageing fields. Most oil fields in the country that have a capacity of at least 300,000 b/d are currently in the second half of their lifecycle now. But less than 30% of their reserves has been extracted with the rest needing cutting edge technologies to be recovered. It is noteworthy that by application of new technologies, the rate of recovery from different oil reservoirs could be brought to above 80%.
One of the reservoirs which Iran hopes to enhance recovery from is Bangestan in Mansouri field. Bangestan is up for grabs under Iran's new-style oil contracts. Over recent years, production from Mansouri-Bangestan has been studied by a committee of experts at the Reservoirs Directorate of National Iranian Oil Company with the objective of defining a scenario for optimal production.
According to the Corporate Planning Department of NIOC, the scenarios envisaged for enhanced recovery from this field include natural depletion, gas and water injection with the objective of examining different parameters including flow and down-hole pressure. This field enjoys very good potential for development in the future. However, Mansouri-Bangestan reservoir needs further studies which have already started. Some of these activities involve artificial lifting, hydraulic fracturing or fracking and enhanced recovery.
Iran's petroleum industry and particularly National Iranian South Oil Company (NISOC) have over recent years been working to bring crude oil production and processing capacity from 60,000 b/d to 100,000 b/d. This project has had 97.5% progress. The only remaining part of the first phase of development of Mansouri field is to complete an under-construction desalting unit which has a capacity of 75,000 b/d. It is expected to come online in the second half of the current calendar year which ends in March 2017. Conducting studies for enhancing production from this field to 150,000 b/d is another objective sought within the framework of development of this reservoir.
The high rate of recovery has created a unique opportunity for Mansouri field, thereby increasing the significance of this field. The latest surveys show that the average recovery rate in Iranian fields stands at 28%. The recovery rate of Asmari reservoir in Mansouri field is estimated at 47%, indicating the high potential of this oil field.
Mansouri field is located 60 kilometers south of the oil-rich city of Ahvaz, 50 kilometers west of Mahshahr Port and 40 kilometers east of Ab Teymour field. Discovered in 1963, the field first started production in 1973. Currently, more than 52,600 b/d of oil is being extracted from Bangestan reservoir of Mansouri field which lies within the jurisdiction of Karoun Oil and Gas Production Company.
The first well in Mansouri field was drilled in 1963, clearing the way for production from Asmari. Production from Bangestan reservoir started in 1974 after a second well was spudded to allow oil delivery to a production unit in Ahvaz.
After Mansouri production unit was built in 1980, processing of Bangestan oil was moved from the Ahvaz unit to Mansouri unit.
With a production capacity of more than 1 mb/d of oil, Karoun Oil and Gas Production Company is the largest subsidiary of National Iranian South Oil Company.
An Iranian oil official recently said that Bangestan reservoir of Mansouri field has a production unit with a nominal capacity of 75,000 b/d, a desalting unit with the nominal capacity of 35,000 b/d and a gas pressure booster station with the nominal capacity of 30 mcf/d.
This reservoir is estimated to hold 15 billion barrels of oil in place, 60,000 b/d of which is being extracted. So far, a total of 347 million barrels of oil has been produced from Bangestan which has the capacity to supply up to 79,000 b/d of oil.
Official figures show that the average oil recovery rate in Iran stands at 24%, while other countries have this figure at 48 to 65%. In Iran, the recovery rate in a field like Soroush is 7%, and in Ahvaz is around 35%.
In engineering, maximum efficient recovery has two specifications: This production could be planned for long term and should prove the maximum recovery rate. Therefore, when it is announced that 30% of gas injection in oil fields in southern Iran has not been realized it means that oil production in NISOC-run areas (3.2 mb/d) is not efficient and the reservoirs are likely to have been damaged.
This is not a new issue. In the 1940s, the average output from Iran's wells had been announced at 18,000 b/d. Now due to extraction over these years, this average production has fallen to 2,000 b/d from each well.
As oil wells are in the second half of their lifecycle, onshore wells see a drop of between 330,000 and 350,000 b/d in their output.
Therefore, realization of Vision plan 2020 objectives requires enhanced recovery from ageing reservoirs like Bangestan in Mansouri field.