Iran’s nationalisation of oil in 1951 is popularly championed as an important episode of anti-colonialism in the Middle East. Expelling the Anglo-Iranian Oil Company half a century after the infamous D’Arcy concession, conventional narratives have argued it heralded an era when governments across the region (and Global South, more generally) increasingly wrested control of natural resources from foreign corporations and states. But how does our understanding of this event change when it is examined through the lens of technopolitics? Drawing on archival sources from Iran, the UK and US, in addition to Persian-language newspapers, oral histories and memoirs, this paper reassesses Iranian oil nationalisation by showing how it reproduced the expertise of the very oil company it expelled. It does so by highlighting how technopolitics functioned primarily by concealing certain forms of human agency in oil operations. By focusing on everyday practices in the Abadan refinery, it argues that oil expertise was produced and made unstable through processes that combined human and non-human agencies, including manual workers drawing on their embodied knowledge. The presence of labour made the company’s expertise continuously unstable, requiring various disciplinary practices that aimed to create docile workers, but which also produced subjectivities that unsettled management’s exclusive claim to expertise. The effect of expertise as exclusively a domain of disembodied, universal reason depended on disavowing and erasing manual labour, including attending forms of bodily violence. I show how this effect was then translated into the political discourse of the oil nationalisation movement through various interlocutors – especially visiting journalists – who drew attention to the colonial nature of the company at the same time they praised its technical installations. I follow these discourses as they shaped the implementation of oil nationalisation, such that the Iranian government sought to maintain the universal principles of ‘oil expertise’, marginalising oil workers as political, non-expert actors. My paper concludes that the diminished capacity of labour in the oil industry cannot be taken for granted, but rather should be seen as an effect of active work on the ground.