Study On The Volume Fracturing Numerical Simulation In Low-permeability Rreservoir

With the increasing size of the proven reserves and the continuous development in thelow-permeability reservoirs, there is an increasing focus on reasonable and effective means ofdevelopment, especially for the super-low-permeability reservoirs. Low permeabilityreservoirs have the characteristics of low permeability, filtrational resistance, and poorconnectedness and so on, it is difficult to meet the needs of economic development. It is hardto achieve the expected stimulation effect only on the traditional single fracturing, because ofthe poor supply ability from the matrix to fracture in the low-permeability reservoirs. Volumestimulating to reservoir, achieving the “short distance” from matrix to fracture because ofproducing fracture network. Therefore, proposing volume fracturing technology to increaseoil or gas production, this technology is suitable for low porosity,low permeability reservoir.According to the definition, volume fracturing form a complicated network fracture systemwhich realized the comprehensive transformation of reservoir in three-dimensional direction,it has the vital significance to the exploitation of low permeability reservoirs.This paper established hydraulic fracturing complex fracture model in the lowpermeability reservoir, using the finite element numerical simulation method for solving,making the simulated complex fracture more close to the real description. Using finiteelement method to establish mathematical model of horizontal wells fracturing, this methodcan simulate all kinds of irregular cracks and reservoir boundary effects on productionperformance. In the research of artificial fracturing well numerical simulation, it is successfulto use line unit describing artificial fracture. This method is more flexible accuratedescriptions of the artificial fracture and more close to the actual fracture description, morethan that also predict production performance curves.Based on the research of volume fracturing technology at home and abroad, combinedwith the natural characteristic in low permeability reservoir,we design volume fracturingcracks distribution scheme and carry out the modification method for calculating the volume.Under the condition of natural energy, carried out numerical simulation of fracture networkafter volume fracturing. Study on the influence law of the fracturing effect according todifferent fracture distribution schemes, simulated volumes, crack length and fucture density.Through comparative analysis of simulation results, we draw meaningful conclusions, andprovide a theoretical guidance for the on-site fracturing operation.