1. College of Geo- exploration Science and Technology��Jilin University��Changchun 130026��China; 2. Northwest Branch of PetroChina ��esearch Institute of Petroleum Exploration and Development��Lanzhou 730020��China

The thrust faults developed mainly in thrust nappe belt�� Their hanging wall and footwall overlap se- riously and the angle of dip from the root to the top more changes��which has greatly affected the precision of reser- voir modeling�� In order to solve these problems��the authors made reservoir prediction and evaluation on thrust nappe belt using the method of impedance inversion based on 3D seismic data in combination with drilling data�� The key step of impedance inversion is the establishment of the initial impedance model�� Firstly��the study im- proved initial impedance model accuracy of thrust nappe belt effectively using the modeling method that separates hanging wall and footwall��transforming fault to horizon and then making fusion to stratigraphic horizon�� After that�� the authors made impedance inversion in hanging wall and footwall separately�� and finally�� used the method of body fusion to complete the impedance inversion�� It has been verified by the drilling that the accuracy of impedance in- version based on the method is higher and it lays a solid foundation for reservoir prediction and target evaluation of thrust nappe belt��