油气勘探与地壳深部构造研究

在传统的油气勘探工作中，主要考虑盆地浅部的沉积盖层条件，对深部构造资料利用甚少。对国内外一些含油气区的地壳深部构造特征进行分析，认为沉积盆地含油气丰度取决于地壳总体的结构类型：①凡莫霍面平缓呈斜坡或下凹状的盆地区，油气丰度都很低，而莫霍面隆起区无论盆地基底面呈坳陷状还是隆起状，都可能有油气资源，前者对油气富集更为有利；②花岗质层在结晶地壳中占的厚度比例越少，沉积盖层在地壳总厚度中所占比例越大，对油气富集越有利；③软流圈层隆起高，中、新生代岩浆活动强烈，也有利于油气富集。利用盆地区油气丰度与深部构造的某些相关规律，将浅部与深部的构造研究相结合，可以客观判定盆地中主力油气远景区，以免出现大的勘探决策失误。我国东部、西部地壳结构特征完全不同，油气分布规律亦不同。在西部地区油气勘探中，建议在重点勘探区进行足够量的地壳深部构造区测工作，结合浅部构造条件确定重点钻探目标。此外，根据地幔对地壳作用越强烈的地区油气越丰富，认为很可能油气形成的有机成因论和无机成因论反映了油气形成统一过程中的不同阶段。

Oilgas exploration and study of deep crustal structure.

In the work of traditional oilgas exploration the sedimental cover conditions are mainly taken into account, but the data of deepseated structure are used very seldom. By means of analyzing the characteristics of deep crustal structure of the oilgas regions at home and abroad it is suggested that the abundance of oil and gas content in sediment basin depends on the general pattern of crustal structure: For the basins with inclined or concave Mohodiscontinuity the abundance of oil and gas content is very low, and for the basins with uplifted Moho the oilgas resources may always exist no matter what the crystalline basement is uplifting or concave, but the former is more beneficial for the concentration of oil and gas; The less is the ratio of the thimation. ckness of the granite layer to that of the crystalline crust, the more is the ratio of the thickness of sediment cover to that of the whole crust, the better for the concentration of oil and gas resource; High uplifting of the asthenosphere, strong activities of the MesoCenozoic magma are beneficial also for accumulation of oil and gas. Using such relationship between the abundance of oilgas content and the characteristics of deep crustal structure, combining the study of sedimental structure with the deepseated crust structure can help us to determine the main oilgas perspective regions of the basins more objectively, and to avoid making some big unwise strategic decision in the exploration. The characteristics of deep crust structure in the east and the west parts of China are very different, so the distribution pattern of oilgas resources is different also. It is suggested that for the important exploration regions of oil and gas in the West China the sufficient amount of regional profiles for investigation of deep crustal structure must be conducted to determine the important objective for drilling on the basis of studying the sedimentcover and deepseated structure conditions. Besides, in the light of the fact that the regions where the acting of the upper mantle to the crust is strong are rich in oil and gas, it is considered that the organic and inorganic cause of formation of oil and gas may be reflected the two different stages of one general process of the oilgas for