动态电位法技术在注水油田监测中的应用

Application of dynamic potential technique in the monitoring of water flooding oilfield.

(吉林大学建设工程学院,吉林长春130026)

College of Construction Engineering,Jilin University,Changchun 130026,China

地层介质电阻率的不同会影响地表电位场的分布,因此，可以通过地表异常电位反演出油水同层储层的电阻率分布。采用动态监测技术对地表电位进行测量,将电阻率较高的水泥胶结包围的金属套管看做供电源,消除受供电点与测量电极附近电阻率的影响,并对采集数据进行电流归一化处理、远电极和参考电极空间校正,在任意复杂的地电断面下利用拟线性近似方法对异常观测电位数据进行反演,推算出电阻率值,得到不同时段的注水储层电阻率分布图,从而直观地推断出含油区域,以实现对注水油田的动态监测。测试数据处理结果表明，测试得到的井位与实际的注水井井位非常吻合。

Variable resistivity of stratum medium impacts the distribution of the earth′s surface potential field,and surface abnormal potential can be used to invert the resistivity distribution of reservoir.Dynamic monitoring technique was adopted to measure the surface potential.Taking the metal casing surrounded by cement bond with relatively high resistivity as supply power,the impact of resistivity close to supply power and measuring electrode was removed,and some processing was carried out on the acquired data,including current normalization processing,spatial correction of far electrode and reference electrode.Pseudo-linear approximation method was used to invert observed abnormal potential at random complex geo-electric cross section and calculate resistivity.Then,the resistivity distribution map of water flooding reservoir at different stage was obtained.Therefore,the oil-bearing area can be visually predicted,and dynamic monitoring on water flooding oilfield was realized.Processing result shows that test well location is coinciding with actual water-flooding well location.