Abstract—: A key task of the State Plan for the Development of Russian Gas and Petrochemicals for the Period up to 2030 is the search for constructive forms of coordinating the strategic interests of extractive companies in new oil and gas provinces of Russia’s East with the interests of participants in creating East Siberian and Far Eastern gas and petrochemical clusters. The article assesses the strategic interests of the public joint stock companies Gazprom, Sibur, and Rosneft based on an analysis of the companies' corporate strategies. A methodological approach is proposed for devising a scheme to form variants for strategic alliances between companies using network and simulation models of the investment program of the East Siberian Oil and Gas Complex (ESOGC) megaproject. The authors performed a scenario analysis of the effectiveness and risks of consolidating the free profits of extractive industry projects to implement gas chemical cluster projects. A case study of the project to create the Amur Gas Chemical Complex was performed to assess the variants and possible risks of alliances between Sibur, Gazprom, and Rosneft.