海洋油气渗漏烃蚀变带的地球物理检测及在中国海区的应用

针对海洋油气渗漏可以在近地表沉积层中引起的一系列烃蚀变效应，本文讨论了利用不同手段，分层次进行检测的几种方法.利用烃蚀变带所产生的磁异常现象，在平面上圈定油气渗漏的分布范围，进而寻找海底油气藏.同时，钻井岩芯岩屑的磁性质测量结果可以从剖面上预测下伏岩层的含油气性.最终利用X射线衍射方法(XRD)对典型层位岩石样品的物相测量，进行烃蚀变矿物组合分析并通过镜下鉴定作进一步的综合判断.对渤海海域烃蚀变效应的磁法检测研究结果与遥感及其他方法的研究结果有很好的一致性.对南海3口钻井岩芯岩屑的磁性测量结果表明：两口有油气前景而另一口没有异常.这与实际结果十分一致，同时表明该方法在海区同样可以具有良好效果.

ALTERATION ZONE FROM THE MARINE OIL-GAS SEEPAGE AND ITS GEOPHYSICAL DETECTION METHODS

Some different geophysical detection methods are introduced on the bario of a series of altered effects by the marine oil gas seepage. According to the magnetic anomaly from Hydrocarbon alteration zone,the distribution of oil gas seepage can be determined at plane. Susceptibility measure of drilling samples and the analyses of minerals by x ray diffraction from anomalous magnetic sedimentary intervals have identified that some kinds of alteration minerals exist. The magnetic detect result in Bohai area is consistent with that from remote sensing result. The association between magnetic anomalies and oil gas has been recorded from the survey of the drill cuttings in 3 wells in the South China Sea. It is effective to decide hydrocarbon alteration zone in the near surface sedimentary strata by using magnetic detect method and the others.