Parameters Optimization of Multistage Pump-Off Propped Fracturing in Thick Formation

Based on the proppant index, a production forecast method for thick oil-bearing formation fracturing was deduced. And combined with NPV methodology, treatment scale of multistage pump-off propped fracturing can be optimized. The effects of treatment parameters, such as injection stages, pumping interval, pumping rate, the ratio of pre and post stage pumping rate, on the fracture geometry, conductivity and production were simulated and analyzed. It reveals that two injection stages, 5 minutes of pumping interval and consistent pumping rate contribute to the highest annual cumulative production. Moreover, the injection stages make the most significant influence on production. Optimization results, applied to Kunbei Oilfield, achieved satisfactory application effects. The single well average production was enhanced by7.92 t/d, the stimulation ratio was 13.56, and the stimulation validity was about 270 days.