Prediction study of hydrocarbon reservoir based on time-frequency domain electromagnetic technique taking Ili Basin as an example

基于时频电磁法的含油气有利区预测研究-以伊犁盆地为例

The time-frequency domain electromagnetic(TFEM)sounding technique can directly detect oil and gas characteristics through anomalies in resistivity and polarizability.In recent years,it has made some breakthroughs in hydrocarbon detection.TFEM was applied to predict the petroliferous property of the Ili Basin.In accordance with the geological structure characteristics of the study area,a two-dimensional layered medium model was constructed and forward modeling was performed.We used the forward-modeling results to guide fi eld construction and ensure the quality of the fi eld data collection.We used the model inversion results to identify and distinguish the resolution of the geoelectric information and provide a reliable basis for data processing.On the basis of our results,key technologies such as 2D resistivity tomography imaging inversion and polarimetric constrained inversion were developed,and we obtained abundant geological and geophysical information.The characteristics of the TFEM anomalies of the hydrocarbon reservoirs in the Ili Basin were summarized through an analysis of the electrical logging data in the study area.Moreover,the oil-gas properties of the Permian and Triassic layers were predicted,and the next favorable exploration targets were optimized.

时频电磁法能够通过电阻率和极化率异常直接检测含油气性,近年来在烃类检测中屡获突破。为预测伊犁盆地的含油气性,开展了时频电磁法勘探研究工作。根据研究区的地质构造特征,构建二维层状介质模型,开展正演模拟研究。利用模型正演结果指导野外施工,保障野外采集数据的质量;利用模型反演结果识别、辨别采集数据对地电信息的分辨率,为数据处理提供可靠的依据。在此基础上开展了拟二维电阻率断面成像反演、极化率约束反演等关键技术研究,获得了丰富的地质和地球物理信息。通过对研究区电测井资料进行分析,总结伊犁盆地含油气储层的时频电磁异常特征,并以此为基础对二叠系、三叠系等目标层含油气性进行了预测,优选了下一步勘探有利目标。