Simulation Study On Interwell Fracture Of Simultaneous Fracturing

With the development of shale gas,tight oil and other unconventional energy,conventional fracturing technology is difficult to meet the demand of industry production,and promote the development of new type of hydraulic fracturing technology.Simultaneous fracturing is a new technology that fracturing two or more than two parallel wells at the same time,which aims to generate greater pressure in the reservoir,thereby increasing the density of hydraulic fracture network,to create a more complex fracture network system.This paper fully research the theory and application status of the simultaneous fracturing technology at home and abroad,with boundary element method and the theory of rock fracture mechanics,established multi-crack extension 2D model,and written multi-crack extension program.According to the target reservoir data,firstly,study the interaction of hydraulic fracture?the interaction of natural fracture and hydraulic fracture in single well fracturing and two well simultaneous fracturing.Then the effect of factors is analyzed: injection net pressure,fracture spacing,parallel well distance and stress difference,to explore simultaneous fracturing fracture extension rule.The research shows that,for a homogeneous and isotropic rock,the two fractures from one horizontal well will deviates away,the lateral spacing between the fractures gradually increases and the shear stress between fracture become weak,unable to induce natural fracture extension;while the two fractures from a simultaneous fracturing will propagate toward each other,the lateral spacing between the fractures decreases,and the large stress change area is formed between fractures,can easily induce natural fracture cracking,deflecting and steering.So,simultaneous fracturing is more favorable to fracture deflection,communicate with natural cracks and form a complex fracture network.At the time of simultaneous fracturing,the net pressure and stress difference determines whether the crack is steering and the extent of crack deflection,crack spacing and well spacing determines whether the cracks interact and the influence range of crack interaction.This study discusses the mechanism of the formation of complex fracture network by simultaneous fracturing,analyzes the influence of different factors on the fracture extension,and provides a theoretical basis and reference guide for the actual fracturing construction design.