Therefore, pressure fall-off in these fields is highly likely while they have great potential for higher production. Ab Teimour which was discovered 50 years ago and its current output stands at 60,000 b/d is one of these fields. Bangestan reservoir of this field was one of 12 projects offered for international investment.

Ab Teimour in Khuzestan province is located 25 kilometers west of Ahvaz. It is between Mansouri and Susangerd oil fields. Ab Teimour was discovered in 1961 following implementation of a seismic test. A first well was drilled there six years later to prove the existence of oil. However, production from Ab Teimour began in 1991. Ab Teimour measures 23 kilometers in length and 6 kilometers in width. According to primary calculations, it is estimated to hold at least 15.2 billion barrels of oil in place.

Bangestan's current production stands at 60,000 b/d from 50 wells (29 wells in Ilam formation and 21 wells in Sarvak formation).

Ab Teimour is administered by National Iranian South Oil Company (NISOC), but its production operations are handled by Karoun Oil and Gas Production Company.

In the 130th meeting of the committee of reservoir consultants of National Iranian Oil Company (NIOC), the general plan for the development of Bangestan was discussed in three phases – natural depletion, artificial lifting and water and gas injection.

Given uncertainty of some data and in the light of completing reservoir data, development of Ab Teimour was designed in pre-phase and full-phase stages.

In the pre-phase stage, necessary data is gathered and pilot tests are conducted so that the development project would be updated and finalized. Based on the existing information, the pre-phase flow is forecast at 55,000 b/d and the full-phase flow at 110,000 b/d.

Over recent years, many foreign companies have expressed readiness to develop this field, but due to international sanctions, agreements were terminated. Following the removal of sanctions, several companies including Russia's Lukoil agreed to submit the results of preliminary studies on this field to NIOC in the near future. However, foreign firms had to quit after the United States withdrew unilaterally from the Iran nuclear deal and re-imposed sanctions on the country.

Iran's Petroleum Ministry has given the Ab Teimour data to several companies in order to examine various scenarios by rivals. Each company has submitted a separate proposal to NIOC. Indonesia's Pertamina has suggested 250,000 b/d production and Lukoil 150,000 b/d. Denmark's Maersk plans different scenarios including 200,000 b/d, 300,000 b/d and 450,000 b/d production. Maersk's 450,000 b/d plateau could remain for four decades and this company must operate the field for a longer period of time.

Such output would be achieved in case the recovery rate of Ab Teimour is enhanced from the current 2.27% to 12%.

Technical studies by Iranian experts indicate that the field's output could be increased up to 95,000 b/d. Ab Teimour is estimated to contain 15 billion barrels of oil in place and so far 315 million barrels has been recovered from the Bangestan reservoir. Near this reservoir is erected a production unit with the rated capacity of 55,000 b/d, a desalting unit with the capacity of 55,000 b/d and a gas pressure booster unit with the nominal capacity of 20 mcf/d.

Experts and specialists at NIOC have processed and interpreted 3D seismic test data and identified a new reservoir structure which contains around 2 billion barrels of oil in place.

As the Bangestan reservoir pressure and the wells' stream pressure change, artificial lifting of Ab Teimour in the Bangestan reservoir was planned. This project is now in its final stages and the flow of oil wells from Ab Teimour will be stabilized after artificial lifting system is installed.

Band Karkheh to Undergo Development

West Karoun is a quite vast area on the western bank of Karoun River, extending up to Iran-Iraq border.

West Karoun belongs to oil-rich Khuzestan Province, but during the imposed war in the 1980s and post-war calamities like mined areas, oil exploration and production could not materialize.

However, the valuable oil deposits in this part of Iran are now for certain, a significant part of which lies in the Band Karkheh field which holds heavy crude oil. West Karoun’s fields are mostly shared with neighboring Iraq. National Iranian Oil Company (NIOC) has given priority to the development of these fields for oil production with a view to adding 1 mb/d of oil with an investment of more than $20 billion to national production.

Band Karkheh is an independent oil field, which was introduced by NIOC for investment a couple of years ago.

Measuring 50 kilometers long and 5 kilometers wide, this field is estimated to contain over $4.5 billion with an API gravity of 24 at Ilam and Sarvak geological formations. 

Band Karkheh is administered by the Arvand Oil and Gas Production Company, but its development is upon Petroleum Engineering and Development Company (PEDEC).

2D seismic testing was conducted in the 1960s to examine the existence of oil in Band Karkheh. Later on, the field’s structural plan was identified and a first well was drilled that showed the existence of oil in Asmari Formation. This field lacked any hydrocarbon at that time and therefore exploration operations halted.

In 2007, a well was drilled for the description of the Ilam reservoir, which proved the possibility of recovering at least 1,000 b/d of crude oil from Ilam formation. Sarvak formation is estimated to hold 2.5 billion barrels of oil in place.

In 2012, an agreement was signed between PEDEC and Armed Forces Social Security Investment Company (AFSIC) for the development of Band Karkheh, but the agreement was terminated the following year. Recently a European company has resumed development operations in this field. An agreement is to be signed soon under the Iran Petroleum Contract (IPC) framework for the development of Band Karkheh.

A European firm had discovered oil in Band Karkheh under a deal with NIOC. The company had to leave Iran when international sanctions were imposed on Iran and the development project was halted. Once this company left Iran, PEDEC and AFSIC had signed their memorandum for cooperation.

Drilling of two appraisal wells in the northern and central parts of the field to acquire information about the second phase of development of Band Karkheh in parallel with the drilling of development wells in the southern part are envisaged.

Early production is expected to increase more than 7,500 b/d from this field, but seismic data processing and interpretation will make it clearer.

Oil is expected to be transmitted from Band Karkheh to West Karoun’s pumping station. Meantime, mobile processing facilities are available.

Courtesy of Iran Petroleum