The technological processes and systems of oil & gas exploration and development industry are complex in structure, huge in quantity and great in investment risk. The basic work of technological resource management is weak, so technological rank order and function empowerment have been the bottlenecks of single technological value assessment, which seriously restricts both technological value evaluation and technological development strategy implementation in this industry. Based on genealogical theories and thoughts, this paper constructed the rank order and quantity genealogy of oil & gas exploration and development technology under the guidance of technological valuation and commercialization. Then, natural gas exploration and development technology was taken as an example to design and construct the rank order genealogy of natural gas exploration and development technology in the pattern of 5n geometric series and four rank orders. And the following research results were obtained. First, genealogical development of oil & gas technologies will be an inevitable trend of oil & gas technological resource management. Second, the construction of oil & gas technological product genealogy is a basic relationship index for describing the technological system and its rank order, and it is also a tool for sharing technological innovation achievements effectively and a key tool for verifying the share percentage of technological innovation achievements. Third, deeply exploring the construction of oil & gas technological genealogy will be conducive to expanding the popularization, application and market development of oil & gas technologies and promote the valuation of technological innovation achievements. In conclusion, the technological product genealogy constructed in this paper can not only describe the whole natural gas exploration and development technology system and the basic energy-level relationship between the technologies and realize the resource matching between technological innovation and technological market, but find out the basic function "positions" of innovative technologies to deal with technological innovation and efficiency capacity empowerment, share radix and other problems.