While publicly-available datasets often document how much fossil fuel is extracted within oil-producing countries, they do not generally indicate who is responsible. To address this gap, we constructed the Global Oil and Gas Extraction Network, a dataset containing the extraction sites of the 26 largest oil and gas companies, and the quantities extracted annually from 2014 to 2018, accounting for 67% of total production. Using this dataset, we present a first-of-its-kind network analysis of global oil and gas extraction. We find fifty-eight percent of operations involved joint ownership across companies, demonstrating growing interdependence after industry-wide losses in 2016. Countries in which National Oil Companies (NOCs) were active were less likely to host Hybrid state-investor companies, and even less likely to host Investor-Owned Companies (IOCs), while certain Hybrids and IOCs tended to operate in the same countries; both trends became more pronounced between 2014 and 2018. Reflecting colonial legacies, the seven Big Oil companies, headquartered in either the US or Europe, extracted oil and gas from the most countries. These findings reveal a complex global network of strategically aligned actors, indicative of tacit and explicit transnational industry-state collusion to obstruct climate policies. These findings additionally underscore the need for comprehensive data to support a managed fossil fuel phaseout.