烃类垂向微运移及近地表地球化学效应

油气化探技术的理论基础是烃类的垂向微运移，这种运移是指深部油气藏的烃类可以通过盖层及其上部地层运移到近地表，形成用现代高精度仪器足以检测到的与背景有显著差异的化探异常。以鄂尔多斯盆地某油气开发区实测化探资料为基础，论述烃类自油气藏垂向微运移至地表的证据，探讨由烃类垂向微运移引起的近地表地球化学效应，并建立有效的判别模式，应用于研究区化探异常的含油气性预测，取得了较为明显的地质效果，在化探异常范围内多口井钻获商业油流，证明深入研究地表地球化学异常特征，可以为油气钻探提供有价值的依据。

The vertical micro-migration of hydrocarbon and its near surface geochemical effect

The theoretical basis of petroleum geochemical exploration is vertical micro-migration of hydrocarbon. The migration is referring to the hydrocarbons of deep petroleum fields can pass through the cap and its overlying layers to near surface and form geochemical anomalies, which can be determine by modern precision instrument and differ obviously from background. On the basis of actual geochemical data from a petroleum development area of Ordos basin, the authors expound the vertical micro-migration evidence of hydrocarbon, inquire into near surface geochemical effect which is caused by the vertical micro-migration of hydrocarbon, build up effective discriminant model and apply it to oil and gas bearing prediction of geochemical anomalies in studying area, which has got a positive result.