复电阻率法探测油气研究——以羌塘盆地扎仁地区为例

Study of complex resistivity method in hydrocarbon detection: examples of Zaring area, Qiangtang basin

复电阻率法可以寻找岩性油气藏,适用于构造复杂的羌塘盆地.本文首次报道了在羌塘盆地应用复电阻率法开展油气勘探的研究成果.以扎仁地区布曲组含油白云岩为先验条件,结合地层岩石物性特征,对复电阻率法ZR-CR2测线的频谱参数进行了分析.结果表明,导电性参数可以区分研究区地层岩性,极化性参数能够识别有利油气异常.综合扎仁地区地质、地球物理资料对ZR-CR2测线的拟断面进行了推断解释,总结了莎巧木组含有利油气异常的岩性圈闭具有“一高三低”的响应特征,即视充电率(ms)高、视时间常数(τs)低、视频率相关系数(Cs)低、导电性参数低.建议在ZR-CR2测线视充电率ms值最大处部署油气钻探,以期获得羌塘盆地油气勘探的突破.

Complex resistivity method can be used to detect lithologic hydrocarbon reservoirs,which is suitable for the Qiangtang basin with complex structures in surface and underground.This is the first report on the results of complex resistivity method in petroleum exploration in the Qiangtang basin.Taking the oil-bearing dolomite of the Buqu Formation as a prior condition and combining the physical properties of the strata in Zaring area,the spectral parameters of the ZR-CR2 line are analyzed.The results show that the conductivity parameters can be divided into the stratigraphic lithology,and the polarizability parameters can identify the hydrocarbon anomaly in the study area.Combined with regional geological and geophysical available data in Zaring area,the ZR-CR2 section is deduced and explained,and the response characteristics of the favorable hydrocarbon anomaly of the Shaqiaomu Formation are summarized,i.e.high apparent chargeability(ms),low apparent time constant(τs),low apparent correlation coefficient(Cs)and low conductivity.It is suggested that oil and gas drilling should be deployed at the maximum value of ms of the ZR-CR2 line,in order to obtain oil-gas exploration breakthrough in Qiangtang basin.