评艾菲微重力直接找油兼论GONG直接找油

Evaluation of direct oil detection using Affinity System and comment on GONG direct oil detection

从1991年以来，在中国的油气勘探中掀起了一阵AffintySystem（中译为“亲和系统”，或音译为艾菲技术）的重力在接找油方法的浪潮。由于艾菲技术发明入不切实际的宣传，加上不少“好心”人的吹捧，把该方法说成是：“一种精度很高、轻便、廉价、快速的直接找油技术”，认为该方法找油的成功率在美国可以达到95％。我国一些有影响人士轻信了艾菲技术发明人的宣传，把该方法推广到全国一些石油探区。其实该方法在理论上是站不住脚的．所谓艾菲技术能直接测量与碳氢化合物有关的“微量力分量场”也是毫无根据的，需要我们在理论和实际上加以彻底澄清。艾菲重力仪在一些油田所测量的实际数据的精度均很差，最终成果在交点上的闭会误差往往大于判断油气水的异常幅值。而且该仪器的测量重复性也很差──普查中发现的有利异常区，通过详查，有时甚至发生这个有利异常消失了。这样的仪器是不可信的。我们根据该仪器现有的测量资料来判断：所谓艾菲技术基本上是一种精度很差的重力垂直梯度测量，根本谈不上是什么直接找油新技术。俄罗斯的GONG与艾菲技术的性质不同，GONG是属于一种探索性的试验。它的发明人并没有隐瞒自己的方法及观点，只是理论上似乎已误入歧途，判断“恢复重力异常”的主观性太强。

An upsurge 0f direct oil detecti0n using Affinity System gravity method has been sponsored in Chinese hydrocarbon exploration since 1991. As a result of theinventor'S top exaggeration and quite many blind believers' propagation, the technique has been described as an accurate, easy, cheap and efficient technique, bywhich the success rate of oil discovery may be 95% in America. Because of blindlybel1eving the inventor'S exaggeration,some Chinese important personages have ap-plied the technique to some oil exploration areas in China. As a matter of fact,theAffinity System is unreliable in theory. It is utterly groundless that Affinity Systemcan directly observe 'weak gravity field component'relating to hydrocarbon. It isnecessary for us to clear some geophysicists' minds about the unreliabilities in theory and practice.Affinity gravimeter offers very poor observation data in some oil fields,and themis-ties at intersecting points in final result are often higher than the abnormalrangeabilities which are adopted to detect oil, gas and water. What is more, thegravimeter gives very different data in repeated observations in an area. For example,the favourable anomaly area mapped in reconnaissance even disappears in following detailed exploration. So this gravimeter is very unreliable.We can say from Affinity System data that Affinity technique is basically a vertical gravimetric gradient survey with poor accuracy,and can't be called as a new direct oil detection technique at all.Unlike Affinity System technique,Russian GONG technique is an explorativeexperiment.The inventor shows people his method and opinions frankly, but helikely goes astray in theory. In addition,too much subjectivity exists in determining'recovered gravity anomaly'.It is demonstrated that the background anomaly resulting from severe lithologic variations of subsurface sandstone and shale is much stronger than the weak negative anomaly related to hydrocarbon. Generally speaking, direct oil detection bygravity is un feasible,and direct gas detection by gravity is possible only when gasreservoir is shallow,thick and was formed in late geological age.