中新生代油田与地壳构造的关系及其形成机制的研究

A STUDY OF THE INTERRELATIONSHIP BETWEEN MESOZOIC-CENOZOIC OIL FIELDS AND CRUSTAL STRUCTURE AND THE MECHANISM OFOIL FORMATION

1. 中国科学院地球物理研究所;2. 中国科学院广州地质新技术研究所

本文探讨了国内外深部地壳构造与某些大油气田的关系,得出上地幔隆起区与中新生代油气田区相对应的结论,并讨论了其机制问题。认为上地幔隆起所产生的张应力可以形成大断层(特别是产生一系列正断层),因而形成坳陷盆地或“地洼盆地”,并有较厚的沉积物。其中的有机物质在合适的温度、压力、化学及构造条件下,可以形成石油和天然气。因此,可以根据:(1)有大的莫霍界面隆起区;(2)有巨厚的分布范围广的沉积层;(3)有宜于生油的温度、压力、化学条件及合适的储油构造来预测油田远景区.文中给出了预测实例。

This paper goes further into the interrelationship between deep structure of earth's crust and some big oil fields both at home and abroad, from which we can come to the conclusion that upper mantle upwarpings correspond to Mesozoic-Cenozoic oil and gas provinces. The mechanism of forming oil and gas fields is discussed in the paper. It is agreed that the tensile stress caused by the rising of upper mantle can lead to great faults (mainly the normal faults) so that depression basins or "Diwa basins"with thick sediments are thus and so formed. Organic remains in the sediments are favourable for generating oil and gas. Under certain appropriate conditions of temperature, pressure, chemistry and geotectonics, oil and gas can consequently be accumulated. In this way, prospect oil pools can be predicted according to the following conditions: (1) large upwarped district of Mohorovicic discontinuity; (2) large scale distribution of sediments in great thickness; (3) appropriate temperature, pressure, chemical condition and ideal oil-bearing structure promising well for oil reservoir. Also, predicted examples related are given. It is deemed that Talimu basin and Bohai depression basin might be very much promising for oil and gas.