中国中西部类前陆盆地特征及含油气性

CHARACTERS OF QUASI-FORELAND BASINS IN WESTERN-CENTRAL CHINA AND THEIR OIL AND GAS POTENTIAL

中国中西部类前陆盆地是一种比较复杂的改造型盆地 ,垂向上由不同时期的原型盆地叠加构成叠合盆地 ,并在不同的发育阶段受不同的大地构造背景影响和成盆构造应力场控制 ,在盆地充填中配置不同的沉积体系 ,组合成不同的沉积层序。因此 ,构造和沉积作用是控制该类盆地多期次成烃成藏的主要因素。此类盆地的发育过程至少具备两期成烃成藏条件 ,而沉积层序本身具备生储盖组合条件。在前陆型改造盆地油气勘探中除注意成烃条件以外 ,还要通过恢复盆地原型及其叠合方式、恢复盆地沉积充填的沉积体系配置等 ,加强成藏及后期保存条件研究。

Quasi-foreland basins is a kind of complex reformed basins in Western and Central China which are actually superimposition of prototype basins formed in different stage.The basins were effected by different tectonic settings and controlled by stress fields during basin evolution,thus forming different sedimentary systems and sequences.Hence,tectonism and sedimentation were main factors controlling multiphase hydrocarbon generation and multiphase pool-forming of the basins.The development processes of the basins consiste of two stages of hydrocarbon generation and pool-forming conditons,and the sedimentary sequences themselves also possessed source-reservoir-cap rock complex conditions.To explor oil in this kind of basins,one should pay attention to hydrocarbon generation conditions,study the conditions of pool-forming and late preservation of the pools.