井地电法三维物理模型试验

文中通过采用不锈钢管模拟金属套管，细铜棒模拟供电电极，高阻绝缘板代表油层，紫铜板代表水层，并利用128道网络电位记录仪器水槽模拟实验，获得单一模型、横向和纵向组合模型的地面电位异常。通过研究钢套管井中供电存在高阻或低阻异常体时，地面电位等值线异常规律，可为井地电法研究油气储层或水层提供物理依据。模拟实验结果表明，通过向油井中供直流电，在水（地）面测量电场分布的井地工作方式的直流充电法，对于目标油气藏能够有效地消除其上方电性不均匀的影响，特别是对于上、下几套油水层同时存在，且层与层之间存在一定距离时，井地电法有可能圈定出不同储层的分布范围。因此，此法有可能在油田开发和注水开采中监测以及寻找剩余油气分布发挥重要作用。

3-D physical model experiments of well-to-ground electrical survey.

The paper uses tank simulation experiments to obtain electrical potential anomaly of single model, lateral and vertical array models. The experiment uses stainless steel pipe for simulating metal pipe, thin copper rod for power-supplied electrical pole, high-resistant isolated plate for oil horizon, red copper for water layer and network electrical potential recorder with 128 channels for recording. It can provide foundation for using well-to-ground electrical survey to study oil/gas reservoir or water-bearing layer through studying anomaly regu- larity of electrical potential isopleths on the ground when high-resistant or low-resistant anomalous bodies exit in power-supplied steel-cased well. The simulated results showed that direct-current charge method, which is one of well-to-ground working mode that measures distribution of electrical field on the ground (or on the water surface) when supplying direct current to the oil well,can effectively eliminate the influence of non-uniform conductivity above on objective oil/gas reservoir,especially,the well-to-ground electrical survey can trap the distributed scope of different reservoirs when coexisting several sets of oil-water layers and certain distance exists among these layers. So, this method can play an important role in oilfield development and monitoring in waterflood stage as well as looking for the residual oil/gas distribution.