陆相生油及其衍生热点

对陆相生油而言，关键性的问题是何种地质背景是形成优质油源层和向成油转化的环境。认识之一是古气候和占构造有利因素的叠加，如“陆相、潮湿、拗陷”的学说。70年代以来陆相牛油地球化学研究在陆相油源岩的质、量，成烃转化特征、油气源对比等方面确证了陆相沉积中存在优质源岩和向成油转化的条件，并足以保证陆相大、中型油气田形成的油源供给。陆相有机质的特性衍生出近年油气地学的2个热点，即煤成气、煤成油、未熟-低熟油气，并取得了理论和实践的双丰收。笔者在文中提出了陆相生油的地质构架——环境控源、源控藏。

CONTINENTAL OIL GENERATION AND HOT SPOTS DEVELOPED FROM IT

The integration of the generation, reservoir rock, caprocks, migration, trap, accumulation, and preservation is necessary for the generation and pool formation of petroleum, but in a narrow sense we stress importance of source rocks with high organic concentrations and good quality and their conversion into petroleum. When the theory of continental oil generation was put forward, the geological backgrounds should be known where good source rocks formed and converted into oil. About the above problem, scholars had different views. For example, some emphasized that deep depressions formed in a long geological period benefit the formation of oil source rocks, and some thought that only condition is a beneficial reducing environment formed under a proper system of tectonic movement. Professor Hou Defeng proposed that the key if there is oil doesn′t depends on continental or marine deposits but on the paleoclimate and tectonic divisions there. One of the hypotheses of continental oil generation, i.e. , the view of continental damp depressions, is suggested under the inspiration and guidance of the proposal. Since 1970′s great progress has been made in geochemistry of continental oil generation e. g ., the quality and concentration of organic matter, the criterion of assessment of source rocks, the conversion and characteristics of hydrocarbon formation.The source rocks of continental oil may be determined through oil source correlation by means of biomarkers and isotopes. The Daqing Field and other oil fields prove that good qualities and huge volume of continental source rocks exist indeed and are enough to supply oil source for continental large and medium scales of oil field. The achievements in geochemical research greatly deepen the understanding of the continental oil generation. The theory of continental oil generation will become more scientific and perfect by macroscopic survey on geological background in combination with microscopic investigation on texture, and will guide more effectively exploration of continental petroleum. By investigations on characteristics of continental organic matter, some new fields of the continental oil and gas generation are derived, e. g., the coal derived gas formed by coal measure organic matter and the coal derived oil generated by coal macerals containing considerable amounts of oil potential carbon if coal measures are deposited under special sedimentary conditions, especially, in a relatively reducing environment, such as the Turpan Hami Basin in our country. In addition, because continental organic matter contains the matters with lower activation energy, such as suberinites and desmocollinite, it is easy to produce hydrocarbons through degradation at Ro values of about 0.3% to 0.6%. Differing from normal oil fields probed now, these hydrocarbon accumulating pools form at an immature stage, i. e ., they are immature oil pools. In our country, the fruitful achievements have been made theoretically and practically in the three hot fields derived from the theory of continental oil generation in recent years. As for the geological backgrounds of continental oil generation, we suggest a geological framework, i. e ., environments control source rocks and source rocks control oil deposits.