Drilling relief well is the ultimate means to control blowout

which connects the relief well and blowout well in a certain layer to input high-density drilling fluid or cement into the accident well. In order to improve the connection efficiency of the two wells

a transient electromagnetic（ TEM） relief well detecting system based on giant magneto resistance（ GMR） sensor array is proposed. Based on the GMR sensor signal model

the magnetic field distribution of relief well and accident well is studied and the TEM detection system of relief well with GMR sensor array is designed. Simulation experiment results demonstrate that the proposed system can effectively improve the precision of TEM system

which can provide important information for the drilling procedure of relief well.