H. Ahmadov was born in 1906 in Agudi village of Sisian district of Armenia. He graduated from Geological-Exploration Faculty of the Azerbaijan Industrial Institute (now Azerbaijan State Oil and Industrial University) on the specialty of engineer-geologist in 1933.
H.Ahmadov received a PhD in Geology and Mineralogy in 1947, Doctor of Sciences in 1956. He was elected as a corresponding member of ANAS in 1964 and an active member of the Academy of Sciences in 1967.
After graduating from the institute, he worked as a Geologist of the Desert Party in Azneft Union. In 1942, he was appointed director of the geological exploration department of the Az-Oil Exploration Trust, where he studied structural mapping, drilling analysis and summarizing the results.
H.Ahmadov was appointed deputy director on scientific affairs of the Azerbaijan Scientific Research Institute of Oil and Geological Exploration in 1949, director of the same institute in 1951 and in 1955 he was appointed Deputy Director on Geology of the Azerbaijan Scientific Research Institute of Oil Exploration (nowadays Oil and Gas Research and Design İnstitute). H.Ahmedov paid great attention to the study of the Gobustan-Shamakhi oil-gas region and the results of his researches were reflected in the monograph "Gobustan's geology and oil and gas content".
H.Ahmadov was appointed as the first director of the Azerbaijan branch of the Scientific-Research Geophysics İnstitute of Soviet Union in 1965. As a prominent scientist and geologist he was the founder of scientific researches in the field of geology and geophysics, and has been an active participant in the opening and adoption of major oil and gas condensate fields in Azerbaijan (Garadagh, Kenizdagh, Duvanny, etc.). Industrial development projects of Kurovdagh, Mishovdagh, Neft Dashlari, Kum-deniz, Umbaki and others were developed with his participation. His fundamental works in the study of reservoir properties of lithology, petrography, Pliocene-Miocene and cretaceous deposits have gained him great popularity.
The study of geological structure and prospective areas of oil and gas deposits of the Republic, especially Gobustan, was specially important in H.Ahmadov's researches. He was one of the first organizers of researching and exploring Azerbaijan's Mesozoic sedimentation. He was awarded the prize named after I.M Gubkin for the monograph "Mesozoic sediments and prospects of oil and gas content in Azerbaijan".
The scientist is the author of 160 scientific works, including 12 monographs. More than 30 doctors of sciences and philosophy have been trained under his supervision.
H.Ahmadov was chairman of the Scientific and Technical Society of Azerbaijan Oil and Gas Industry and twice awarded with the Order of Glory.
Academician Hasan Akhmadov died in Baku in 1981.