Study Of Fractrue Technics For Deep Volcanic Gas Reservoir In Daqing Explore Field

The paper are in view of the condition existing natural fracture and post fracturing forming multi-fissured on Daqing outer-ring deep zone volcanic rock, through core test determines difference pressure condition,and alternation regular of core permeability,porosity and rock pore volume compressibility,on the base considering two conditions of correlate between pressure and leak off,and fracturing natural fracture,established fall off curve analysis mathematical model,utilize G function to decide formation nature fracture's parameter of developing extent,open pressure,closed pressure etc.,pre-determination accuracy fluid efficiency and fracture propagation condition;based on the differentiate between deep volcanic rock and normal sandstone break mechanism establishing two types of "multi-layer steamed bread " and "cactus" which can relatively description the physics and mathematical model of volcanic rock fracturing extend process of " multifracture "; on the bases of elastic mechanic developing terrestrial stress profile analysis software,which can utilize sonic logging datum calculating the profile of terrestrial stress and rock mechanic,and first achieved the combination type from geologic layering to terrestrial stress layering,heighten the scientific and pertinence on fracturing design.Based on above research,synthesize considering the respect on stress profile,fissure open and extend mechanism,leak off diagnose achievement etc.to optimize fracturing design,optimize treatment raw materials,in view on well site multi-fracturing,high friction resistance,low differential stress between reservoir and barrier bed,high leak off problem etc.,definition correspond effectively control measure,thereby forming a set relatively mature stimulation technique for Daqing exploration area deep volcanic rock gas reservoir.Because of utilizing of technology supporting measures,the unfavorable factors of early screenout of stimulation has been settled satisfactory.Success rate of fracturing has improved from 36.0%in 2002 to 90.9%right now.