Abstract: The method of producing the remaining reserves by in filling wells is widely adopted in the secondary and deep de- velopment of high dense oil in D84 block.To deepen the de- velopment of horizontal,a series of monitoring,including producing degree of horizontal section and the thermal con- nection in wells,are performed to guide the well stimulation of horizontal well and the implementation of combined steam injection.To put SAGD technique to increase the recovery ratio is revolutionary in the development of high dense oil; and the monitoring technique is effectual to guide the SAGD adjustment and control through the real time trace of the for- mation of steam core,and the flow temperature and pressure on the well bottom.