Refracturing technology for low permeability sandstone reservoir in Erlian Oil-ield

The low permeability sandstone reservoir in Erlian Oilield has very high heterogeneity, its recovery percent is only 11.2 percent, total water cut is up to 91 percent. Reservoir physical property, percolating property and water drive erformance were analysed, and oil layer was classiied three kinds, main pay, hypo-main pay and non-main pay, then established classiication criterion for oil layer.Aim at main pay, studied stress ield after water looding and optimized fracturing parameters. Fracture conductivity is 25~30 μm2 ·cm, and fracture length is about 100 m, average increased sand volume per meter increases from 0.5 m3 to 1.1 m3 , and application in Ha301, Ha76 fault block has acquired good effect, and achieved hypo-main pay effective production.