基于水系多样性影响下的砂岩储层流体识别技术探讨

地层水矿化度变化大的地区测井解释难度大,易得出错误的解释结论。以测井响应机理研究为基础,依托阿尔奇公式中的电性、物性和含油性之间的关系,提出了水层底部包络线法、视地层水电阻率法和自然电位与电阻率乘积法。分别以水系相对集中的A井考查水层底部包络线法和视地层水电阻率法识别水系的准确性,以水系相对变化大的B井区考查自然电位与电阻率乘积法直接识别流体性质的实用性。结果表明,当水系相对集中为两套时,水层底部包络线法和视地层水电阻率法可以很好地识别不同水系,为在同一套水系中进行流体识别奠定了基础。当水系变化较大的情况下,自然电位与电阻率乘积法不受水系的干扰,直接识别流体解释符合率达到了80.9%,对于其他地层水矿化度变化大的地区有重要的借鉴作用。

The discussion on fluid identification technologies in the sandstone reservoirs based on diversity of formation water salinity

Formation water salinity variation in a region will cause difficulty logging interpretation,easy to draw incorrect conclusions. Take the log response mechanism research as the foundation, depends on the relationships between the electric properties,physical properties and oiliness in the Archie's formulas, proposed bottom water layer envelope method, apparent formation water resistivity method, and spontaneous potential and resistivity product method. Respectively, the relative concentration of A well water system to examine the accuracy by the bottom water layer envelope method and apparent formation water resistivity method,and water system in large relative changes of B well to examine spontaneous potential and resistivity product method to directly identify the fluid nature of the product practicality. The results show that when the formation water salinity in relative property, the bottom water layer envelope method and apparent formation water resistivity method can identify water system correctly, for identifying the same set of fluid lay the foundation. When in the variety of formation water salinity, spontaneous potential and resistivity product method is not interferred by water system that can distinguish the fluid explaination directly,and the coincidence rate had achieved 80.9%.This could be the important model function for some other areas with multiple formation water salinity.