基于物性分析建模的时频电磁反演及储层评价——以准北缘石北构造带为例

Time-frequency electromagnetic data inversion and reservoir evaluation based on physical property analysis modeling:A case study of the Shibei structural belt on the northern margin of the Junggar Basin

时频电磁法(TFEM)在油气勘探中发挥着重要作用,数据反演中模型精度对反演精度影响很大,充分利用已知资料精确建模可有效降低反演的非唯一性、提高反演精度。基于准北探区实际资料,对研究区电测井数据进行高斯分布统计分析,获得各地层的电阻率均值、离差等特征数据,据此提出对研究区上、下构造层及不同地层进行分层电性建模的方法;通过火成岩储层岩石频散测试分析,获得探区不同油气饱和度火成岩的频散特性,同时依据该地区时频电磁油气检测结果与钻井含油气信息建立油气电磁属性识别模板。示例展示了通过分层建模和反演获得的电阻率和极化率剖面,以及剖面的分析、解释结果,指出了含油气有利目标。文中的建模方法和油气目标解释思路可为类似地区的油气储层评价提供有价值参考。

Time-frequency electromagnetic(TFEM)method plays an important role in oil and gas exploration.In addition,model accuracy in data inversion has a great impact on the inversion accuracy.In order to effectively reduce the non-uniqueness of inversion and improve the inversion accuracy,it is necessary to make full use of existing data for accurate modeling.Based on the actual exploration data of the Northern Junggar Basin,this paper uses Gaussian distribution to statistically analyze the electrical logging data of the study area and obtains characteristic electrical data of each stratum,such as the mean value of resistivity and deviation,so as to propose a layered electrical modeling method for the upper and lower structural layers and different strata in the study area.Through the rock dispersion test of igneous greservoirs,the dispersion characteristics of igneous rock with different oil and gas saturation in the study area are obtained.Furthermore,according to the TFEM oil and gas detection results and the oil and gas information during drilling,an identification template for oil and gas electromagnetic attributes is established.The case shows the resistivity and polarization profiles obtained through layered modeling and TFEM inversion,as well as the analysis and interpretation of profiles,have identified favorable targets for hydrocarbon exploration.The modeling method and hydrocarbon target interpretation idea in the paper can provide a valuable reference for hydrocarbon reservoir evaluation in similar areas.