Study on refracturing technique and its application in oil well with medium-high water content at Ansai oilfield

Since 2000,the refracturing technology,mainly the in- ternal diversion fracturing,has already become the dominant measure to reclaim oil well at Ansai oilfield,with an effective rate up to 94.3%,and the average oil increase of a single well above 1.4 tons per day.In recent two years,partial oil wells are at the development phase of medium-high water. Through studies on the reservoir nature,the character of water content,the initial reclamation parameter,the distri- bution of residual oil,the oil well and horizon selection,the selection of fracturing fluid and the optimization of produc- tion parameters,a technology that is adaptive to the refra- curing of the oil well of medium-high water content at An- sai oilfield.The on-site application in twelve well shows that the effect of controlling water and increasing production is obtained.