测井多因素评价分析技术及处理方法

THE LOGGING MULTI-FACTORS ANALYSIS TECHNIQUE AND PROCESSING METHED

油田开发进入中后期以后,普遍存在油井单井产量低、综合含水率高的问题。随着可开发新区块减少,下一步的重点就是老区块中未开采的单砂体、薄砂体以及水驱剩余油的挖潜。利用测井曲线是识别单薄砂体及剩余油是一种重要的手段,测井曲线质量精度高,是准确认识地层真实特征的前提条件。在钻井过程中,地层受到钻头的机械力以及泥浆循环中的冲刷、侵入和浸泡,使井壁周围地层岩石结构受到一定破坏,形成一个"速度变化带"。这种由于井眼几何形状遭受破坏会使井眼扩大或井壁表面变得不平滑,以及泥岩蚀变等方面的问题引起声波时差、自然伽马、密度测测井值的偏差,降低了测井资料的质量。利用LEAD测井综合应用平台着重针对易受井眼条件影响的声波时差、补偿密度曲线和易受井径、泥浆密度及仪器偏心影响的自然伽马曲线进行校正,以减小和消除非地层因素影响测井资料准确性的程度,从而提高测井质量精度。

In the middle and late period of oilfield development, a single well production is generally low and the total water cut is high. With the reduction of new block development, the focus of next step is the potential of old block of remaining oil of untapped single sand body,thin sand body and water flooding. Well logging curves are the important means to identify thin sand body and residual oil. High quality logging curves are the prerequisite for accurate understanding of the real feature of formation. In the process of drilling, formation is attacked by the mechanical force of a drill bit and washed, invaded and soaked by mud circulation, which makes the formation around the borehole destroyed, forming a 'velocity change zone'. Such wellbore geometry damage will cause borehole enlargement or unsmooth wall surface, and mudstone alteration and other problems will cause deviation of interval transit time, natural gamma ray and density logging, which reduces the quality of logging data. LEAD integrated logging platform is used to reduce and eliminate the influence of non-stratigraphic factors so as to improve the accuracy of logging quality.