Research On The Automatic Identification Method Of Multi-layer Column Damage In Transient Electromagnetic Method

With the continuous deepening of oil and gas development work,most of China's oilfields have gradually entered the middle and late stages of exploration and development,with various degrees of damage appearing in the string,but the damage of the multi-layer string can only be detected.So,how to identify the location,degree and even type of damage from complex detection data will be a hot research topic in the petroleum field.Based on the pulse eddy current detection technology,this paper will focus on the automatic damage identification method of the transient electromagnetic for multi-layer string and signal processing software design.In order to better realize the automatic identification of multi-layer string damage,this paper firstly preprocesses the logging data adaptively to eliminate the influence of abnormal data and temperature drift on logging data,and uses the depth compensation correction method based on casing positioning to accurately register the depth information of measured data.Then,for the non-uniform columnar multi-layer model in the underground,the multi-layer string damage detection technology is analyzed by the transient eddy current diffusion characteristics of the transient electromagnetic method,and the multi-layer string damage automatic identification technology is used to interpret the wall thickness information of the multi-layer string with high resolution,and the eccentric array detection method is used to further improve detection accuracy.On this basis,the MFC-based electromagnetic flaw detection processing software is designed.The software combines curve preprocessing and automatic recognition algorithms to realize the automatic processing and analysis of logging data and to perform three-dimensional diagram,output and print the interpretation results of pipe wall thickness.Finally,the electromagnetic flaw detection processing software is used to analyze and interpret the well field measured data of single-layer and multi-layer string.The results show that the automatic identification method and processing software of transient electromagnetic multilayer pipe string can realize highly automated logging data interpretation,and the interpretation results of pipe wall thickness have better resolution.