Abstract: After 20 years of depressurization exploitation, Jin 25 block of extra heavy oil reservoir has entered the late period of steam stimulation, each development index has become worse and worse. To slow down the decline, the integrated use of well seismic technology, secondary logging interpretation technique, mathematical model and in situ experiment and dynamic analysis, the remaining oil distribution law of reservoir steam stimulation at late period has been made clear, and the sound well, sidetracking branch overhaul, water Hirai, nourishing layer, optimization of steam injection supporting technology have been implemented and improved, which achieved good economic and social benefits.