The memoranda of understanding (MoUs), signed with the China Petroleum and Chemical (Sinopec) , Saudi Aramco and Japan’s JX Nippon Oil & Energy, are part of a $25bn upgrade project on five of the former OPEC member’s refineries, reports Reuters.

Indonesia aims to upgrade its refineries as well as develop new refineries as part of its energy reforms, which is intended to cut corruption and meet energy demands.

Under the MoUs, the firms will carry out feasibility studies of the upgrades.

Reuters quoted Pertamina chief executive Dwi Soetjipto as saying to reporters that the company is planning to sign binding agreements within six months.

"(The upgrades) will be completed in around four years and there will also be a growth in demand so this alone won’t be enough to fill the demand gap.

Soetjipto said that Indonesia’s Refinery Development Master Plan aim is to double its crude processing capacity from 820,000 bpd at present to 1.68 million bpd.

Pertamina also plans to more than triple gasoline output from Indonesia’s refineries from 190,000 bpd in 2012 to 630,000 bpd by 2025, and more than double diesel output to 770,000 bpd by 2025 from 320,000 bpd in 2012.