Nikolai Alexandrovich Kudryavtsev (Russian: Николай Александрович Кудрявцев; October 21, 1893, Opochka – December 12, 1971, Leningrad) was a Soviet Russian petroleum geologist. He is the founding father of modern abiogenic theory for the origin of petroleum, which states that some petroleum is formed from non-biological sources of hydrocarbons located deep in the Earth's crust and mantle. He graduated from Leningrad Mining Institute in 1922, obtained a Dr.Sc. in Geology and Mineralogy in 1936, and became a professor in 1941. Kudryavtsev started his geological career in 1920 at the USSR Geological Committee. In 1929-1971, he worked for the All-Union Geological Research Institute (VNIGRI). His only son died defending the Brest Fortress at the beginning of Nazi aggression against the USSR. Kudryavtsev conducted regional geological studies that resulted in discoveries of commercial oil and gas in the Grozny district (Chechnya Autonomy), Central Asia, Timan-Pechora, and other regions of the Soviet Union. He led reconnaissance exploration research in Georgia. He compiled the program of key exploration wells in the West Siberia in 1947 that paved the way to the new era of oil and gas production in Russia that started with first gas gusher near Berezovo in 1953.