Abstract
The transnational economic community of the hydrocarbon industry players or societas petroleatorum, including the largest oil and gas companies and their associations, specialized international intergovernmental and nongovernmental organizations, arbitrations, experts and scientists, generates an equally unique set of ordinary lex petrolea rules, acting to regulate crossborder relations between States and foreign investors in the hydrocarbon exploration and development sector. States, because of their sovereignty, do not make a deal according to foreign law, and investors, in turn, do not trust the host jurisdiction. Lex petrolea in this sense provides the regulatory neutrality that the parties seek by denationalizing the applicable law and reducing commercial and legal risks. The author substantiates the concept of lex petrolea in private international law, analyzes the reasons behind its spread, based on the doctrine and practice of international investment arbitration. This article also considers the problem of qualification of investments in the oil and gas sector.