Oji was born in 1967 in Shiraz and graduated with an oil engineering degree from Iran’s Oil Industry University in 1988. According to state media, Oji graduated third in his class. He began his career working as an engineering analyst and subsequently advanced through the ranks of National Iranian Oil Company subsidiaries. In 2005, he was appointed managing director of Southern Zagros Oil and Gas Production Company, a position he held until 2009.
In 2012, the European Union designated Zagros Oil and Gas Production company due to its links to Iran’s proliferation-sensitive nuclear activities or development of nuclear weapon delivery systems. The EU removed these sanctions as part of the Joint Comprehensive Plan of Action (JCPOA), or the Iran nuclear deal, in 2016. Canada had also designated Zagros Oil and Gas Production Company as an entity contributing to Iran's proliferation-sensitive nuclear activities or its development of chemical, biological or nuclear weapons or their delivery systems in 2013.
In the second Ahmadinejad administration (2009 – 2013), Oji acted as deputy oil minister and managing director of the National Iranian Gas Company (NIGS). He was simultaneously a member of the board of directors of the Oil Industry University and the Oil Industry Retirement Fund.
During his term as managing director of NIGS, Oji proposed launching the “Islamic Pipeline” after Iran was excluded from the Nabucco pipeline, which intended to deliver natural gas from the Caucuses to Europe by way of Turkey. Oji envisioned creating a rival pipeline that would extend through Iraq and Syria and eventually on to Europe, but the project ultimately went nowhere.
Despite sitting on one of the largest natural gas reserves in the world, the Islamic Republic’s pariah status and risky business environment have left its natural gas sector underdeveloped and untouched by the liquified natural gas (LNG) revolution.
Some oil development news sites have written that, following US sanctions during the Ahmadinejad administration, Oji transferred gold bars to neighboring countries to skirt sanctions and facilitate goods-for-goods deals.