砂岩厚度和物性变化对油气成藏影响的模拟实验

在对东部滩海地区新近系油气成藏地质综合研完的基础上，利用二维模型进行了输导断层两侧砂岩厚度和物性的变化对其成藏影响的模拟实验。结果表明：①输导断层两侧的厚砂层最易成藏，即使在物性较差的情况下，也有可能含油；输导断层两侧的中等厚度砂层。若物性较好，为油层；若物性较差，距输导断层由近及远依次为油层、油水同层、水层；输导断层两侧的薄砂层，只有在物性最好的情况下，才可成为油层，否则为水层，砂岩厚度的变化对其成藏起着决定的作用，而物性的好坏则对其成藏有着重要的影响，它们之间存在着一定的互补关系；②与输导砂层和输导断层间接相连的砂层，其成藏不仅与其本身的厚度和物性有关，还取决于输导砂层的厚度和物性，只有与厚度大且物性好的输导砂层相连时，才有利于油的聚集。可成为油层；否则，不利于油的聚集，为油水同层或水层。输导砂层的厚度和物性变化是影响砂岩内部成藏的关键。

The Simulation Test for Effects of Changes in Sandstone Thickness and Quality on Hydrocarbon Accumulation

On the basis of comprehensive geological study of hydrocarbon migration and accumulation of Neogene in eastern beach area of China,the simulation test for effects of changes in sandstone thickness and quality on hydrocarbon accumulation in two sides of conducting fault is conducted by means of 2-D model.The result shows that in one hand,in two sides of fault,the thick sand layers is the most favorable to become a reservoir;the intermediate sand layers are regarded as oil layers where quality is good and as water layers where quality is poor,appearing the oil layer,the oil-water layer and the water layer in turn in terms of distances from the conducting fault;the thin sand layers could not become oil layer until the quality is the best,otherwise,become water layer.Hence,the sand layer thickness plays a decisive role,while the quality has an important effect on becoming a reservoir,both of which there have been some complementary relations.In the other hand,the sand layers indirectly connected with the conducting sand beds and the conducting faults,the reservoirs are not only related to their thickness and quality,but also depend on the conducting sand beds' thickness and quality.Only connecting such sand beds with big thickness and fine quality,could the petroleum accumulation or oil layer be favorably formed;otherwise,oil-water layer or just water layer be formed instead of become oil layer.The changes of conducting sand beds' thickness and quality are the key for affecting petroleum accumulation within sand layers.