The companys president director, Karen Agustiawan, said in a press statement here on Saturday that the acquisition was part of the companys efforts to achieve its vision of becoming a world-class company.
"The corporate action is a strategic stepping stone to expand its business abroad, especially in countries with abundant oil and gas resources such as Iraq," she said.
She noted that Pertaminas expansion overseas was aimed at supporting the governments program of sustainable energy resilience.
The acquisition of a 10 percent share, or a participating interest in West Qurna I Block, was carried out by PT Pertamina Irak Eksplorasi Produksi as Pertaminas subsidiary.
Besides Pertamina, ExxonMobil also sold 25 percent of its shares in the block to PetroChina Co.
ExxonMobil will later only control 25 percent of the shares in the block, but it will remain as the operator.
The remainder of the shares belong to Iraqi state-owned company South Oil Company (25 percent) and Shell West Qurna BV (15 percent).
West Qurna I Block, which is located near Basra, in South Iraq, currently produces some 500,000 barrels per day.
By acquiring 10 percent, Pertamina will receive 50,000 barrels per day, but in the future, production in West Qurna I is estimated to reach more than one million barrels per day.
West Qurna s oil reserves are known to be around nine billion barrels.
Pertamina is also now involved in acquisitions of shares in Block 405a belonging to ConocoPhillips Algeria Limited in Algeria, valued at US$1.75 billion, or about Rp20 trillion.
With the acquisition of Block 405a, Pertamina would have an additional supply of 23,000 barrels per day.
Meanwhile, Pertaminas additional reserves from Block 405a are more than 100 million barrels of oil.
Pertamina officially has three main oil fields, namely Menzel Lejmat North (MLN), Ourhoud, and EMK in Block 405a, which was initially controlled by Conoco.
After the acquisition, Pertamina will control 65 percent of the participating interest in MLN and act as the operator.
In Ourhoud and EMK, meanwhile, Pertamina will have 3.7 percent and 16.9 percent participating interest, respectively, but it will not be the operator of the fields.
Oil production from Block 405a is to be processed at Pertaminas refineries.
reporting by Kelik Dewanto
(EDITED BY INE)