BZ 25-1is a typical offshore low permeable oilfield. In order to accelerate the effective use of low permeability reserves in this field, the corresponding technical countermeasures have been taken against the difficulties in large-scale hydraulic fracturing operation in the sea, and the drilling platform was used as a carrier. Through the optimization design of fracturing parameters, Halliburton staged fracturing tools were adopted, by which three to five stages of fracturing were successfully conducted for the offshore horizontal well of two casing completion wells in the field for the first time domestically. At the early stage of postproduction, liquid flew back to the hole through Ø6 mm nozzle after fracturing, the daily oil flow rate was 109 and 109.8m3/d, the yield ratio reached 5~8 times of vertical well in the same areas. The effect of stimulation is obvious, which provides experience for high efficiency and economical development of offshore low permeability reservoirs.