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The main reservoir space of tight fractured reservoir is matrix, natural fracture is theseepage channel, double wing symmetric major fissure cause by the conventional fracturing, itis difficult to obtain the expected stimulation effect, even if the initial yield is higher, valid alsodifficult to maintain long-term, the key of improve the tight sand reservoir and fracturereservoir stimulation effect is enhanced the vertical permeability and maximum communicationnatural fracture.At present the deep volcanic rock, Gulong shale reservoirs, Budate Group of Hailaer Basinand Coal Seam are fractured reservoir, part of the tight reservoir using conventional fracturingtechnology is difficult to increase production; Network fracture is the use of reservoir twohorizontal stress difference and fracture extension net pressure relation, Once fractureextension net pressure is greater than the two horizontal stress difference, It will Produce abranch joint; Branch joint communicate natural fractures, along the natural fractures continuesextension, eventually can be formed "nets fracture " system.Network fracturing technology through the process control to achieve different types ofreservoir formation network system. The first study natural fracture existence conditions, nearwellbore multi-crack fracturing mechanism, and in multi-crack extension process and afternatural fracture intersection, the natural fracture open and steering extension condition, and atthe same time, according to the reservoir level two-phase stress differences, analysis the controlfactor to produce branch crack, thus realize network forming theory research under the naturalfracture nondevelopment reservoir. And then according to the network fracture formationmechanism, analyzed the control factors of the network fracture formation to determine themain control factors, and establish the well(layers) selection method affect by the main controlfactors, and finally implementation the process.The paper through the research of the natural fracture shear failure mechanism, naturalfracture tensile failure mechanism in thenatural fracture reservoir, and natural fracture openmechanism, steering extension mechanism in the major fissure extension, identify the maincontrol factors of the formation of network fracture, to realize the network fracturing; at thesame time, through the research crack nondevelopment reservoir (or natural fracture difficult toopen and extended reservoir), forming branch crack rock fracture and extension mechanism; toestablish a set of "network fracturing" technology suitable for daqing tight reservoirs tosignificantly increase the production after fracturing.Through two years of theoretical research and field test, established a well(layers) selection method which based on the network fracture formation mechanism, and establish theoptimization method of network fracturing injection technology for different types of reservoir,through the field experiment in Hailar Nantun group, Budate fracture development reservoirand Fuyang nondevelopment reservoir, total test6Wells include13layers, after fracturing theoil recovery rate contrast conventional fracturing increased by50%.
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