Study and application of thermal recovery technology after water flooding at the late development stage in steam drive well group of test area in Qi40 block

In October 1998,steam drive pilot of 4 well groups are carried out in Lian Ⅱ layer of Qi-40 block.Steam drive expansive experiments of 7 well groups are carried out in July 2003.There are 11 well groups in steam drive area of Qi-40 block at present,which are all at the late development stage of steam drive breakthrough.Numerical simula-tion is applied to the late development stage of thermal recovery technology after water flooding to improve the eco-nomic efficiency of steam drive and to provide the adjustment of technology options for industrializing area.Injection temperature,injection rate and other parameters are designed to field show obvious effect.Oil-steam ratio climbed from 0.13 to 0.15,which provide a reasonable adjustment model for steam drive in late development stage of steam flooding.