Along with the development of China's economy and the industrialization process of all countries in the world, the demand for oil and gas is growing quickly. In light of growing requirements for oil and gas resources abroad and the fact that China's internal supply is not enough or even deficient at the present time, we suggest that we must use the resources through different ways; at the same time, determine to have a foothold in national resources and to build up the strategic reserve base of gas and oil resources for safety which can ensure reliable and stable supply. At present, during the processes of the exploration and exploitation of oil- and gas-fields, there still exist large quantity of the oil and gas, which are buried more than or much greater than that defined by the depth lines and stable temperature. Furthermore, the extensive discovered deep hydrocarbon reservoirs have raised strong challenges to traditional oil and gas generating theory. Based on studies of sedimentary construction, crystalline basement, deep medium and physical environments (mainly referring to temperature and pressure) for formation and accumulation of hydrocarbon resources, the following four problems are discussed: (1)There exist marine sediments beneath the continental sediments widely, i. e. dual-phase sedimentary basins(continental phase and marine phase), and the basement is not only the bottom of Mesozoic and Cenozoic basement, but also the old metamorphic rocks basement; (2) The physical and chemical properties, material sources, and reservoir space of the medium in the deep crust supply the material for the formation and accumulation of oil and gas resources; (3)We put forward the new notion of mixing origin of oil and gas(organic and inorganic origins), dominated by organic origins; (4)Oil and gas exploration and exploitation in the second deep space (5000 similar to 10000 m) should be the inevitable trajectory for the further studies and development of the deep potential large-super large hydrocarbon reservoirs.
