Abstract: To solve the development problems such as the rapid decrease of crude production,the bad effect of steam stimu- lation,the sand flow of producing well,and the heterogene- ous mobilization of oil reservoir in W60 fault block,the studies on secondary development on the base of the fine de- scription of pool and the evaluation of development potential are performed.Results show that the recovery ratio is in- creased by 36.3% and the secondary development at the old development area is realized by infilling horizontal wells, supplementing the gravity drainage with steam and superpo- sing horizontal wells.The success of the secondary develop- ment in W60 Block provides an example for the same kind of pool to increase the development effect.