水平井中砂泥岩互层的双侧向测井响应研究

摘要：针对砂泥岩互层的复杂测井环境，采用三维有限元数值模拟方法，计算了多层介质模型的水平井双侧向测井响应。结果表明，井眼半径、泥浆电阻率和围岩（砂岩、泥岩）的电阻率及侵入半径与电阻率对水平井双侧向测井响应都有不同程度的影响。在砂泥岩地层中，井眼尺寸越大，泥浆电阻率越高，对视电阻率的影响越严重；当目的层厚大于8 m 后，视电阻率受围岩（砂岩、泥岩）影响很小，基本上反映地层的真实电阻率，并且曲线变化规律大致相同，此时可近似为三层介质模型；对于低阻侵入，侵入越深，视电阻率越偏离真实地层电阻率。

Response of Dual Lateral Logging on Interbeded Sand-shale inHorizontal Well

Abstract：According to the complex logging environment of sand-shale interbeded formation，the response of dual laterologto multilayered medium model in horizontal well has been analyzed by 3D finite element method. The numerical result showsthat the borehole diameter and mud resistivity，the thickness and resistivity of shoulder bed（mudstone）as well as the radiusof invasion and invasion zone resistivity make obvious influences on dual laterolog response. In the sand-shale formation，thelarger the borehole sizes and mud resistivity are，the more serious influence on Ra is. If mudstone’s resistivity is higher，theapparent resistivity of dual laterolog changes more obviously. The shoulder bed which includes sandstone and mudstone makesno impact on the apparent resistivity and the apparent resistivity curves of variation are nearly the same when bed thickness offormation is beyond 8 meters. The lower the resistivity invasion is and the deeper it invades，the more the difference betweenRa and the real resistivity of formation is.