Application of hydraulic expansion in wells which failed in waterflood

In fracture-cave carbonate reservoirs of the Tahe Oil Field,waterflood substituting oil(WSO) has been used as the main method to improve recovery rate.As explorations are carried out,wells which have failed in WSO increase.It is necessary to tap potential of the failed wells.Analyzingthe reasons for failure,based on conclusions of conventional treatment methods which had failed in theabove-mentioned wells,hydraulic expansion(HE) was proposed to tap potential and improve recovery.Selecting standard for wells using HE was put forward.