评价低电阻率油层的思路

Evaluation of Low-Resistivity Reservoirs

我国各含油气盆地勘探实践表明,低电阻率油气藏储量丰富、产能高,是油田增储上产的重要领域,也是老井挖潜的主要目标。由于低电阻率油层成因复杂多样,给用测井资料对其进行评价带来很大困难,因此必须采用适于低电阻率油层的测井评价技术。通常,低电阻率油层是由高束缚水含量引起的。依据多相流体在多孔介质中的渗流理论,根据油水相对渗透率实验结果,采用多元非线性回归的方法建立油水相对渗透率模型,在准确确定含水饱和度、束缚水饱和度的基础上,可用油水相对渗透率评价此类油气藏。实例证明,该方法不仅简单易行,而且可大幅度地提高解释成功率。

The exploration practices of hydrocarbon-bearing basins in China show that low-resistivity reservoirs are of abundant reserves and high productivity as the important exploration areas for increase of reserves and production in oilfield.Also,they are the main targets for reviews of old wells.However,the complexity and diversity of low-resistivity geneses cause difficult logging evaluations.And the main control genesis-based logging evaluation techniques should be used.In view of the low-resistivity reservoir caused by the high irreducible water content,this paper presents a model for oil-water relative permeability based on percolation theory of multiphase fluids in porous media and lab experimental results,using multiple non-linear regression method,by which such a reservoir can be evaluated using oil-water relative permeability data,on the basis of exact determination of water saturation and irreducible water saturation.Case study indicates that this method is simple to use and makes the success ratio of interpretation greatly improved.