Longfengshan gas field is a typical fractured reservoir with outstanding absorption. In the process of drilling, cementing operation has difficulties of low formation pressure coefficient, active gas and borehole wall stability. According to the characteristics of this block, through cementing measures strengthening, leakage prevention in drilling and completion processes, mud loss control under pressures, well completion method optimization, variable displacement fluid technology, low density slurry system optimization and rational design of structure, the cementing leakage and gas channeling during cement curing have been effectively solved to ensure the cementing quality for effective oil reservoir cementing.