Study On Optimization Design Method Of Volume Fracturing Process Parameters Of Tight Gas Reservoir

In recent years,the direction of oil and gas exploration and development has gradually shifted from conventional oil and gas reservoirs to special reservoirs.The exploration and development of fractured tight reservoirs is particularly important.For the fractured tight oil and gas reservoirs,the conventional fracturing technology is difficult to meet the requirements of productivity,and the volume fracturing technology is usually used to increase production and reform.In the process of volume transformation,it is easy to form a complex fracture network and form an area for increasing production and transformation.The larger the region is,the higher the general production capacity is.Therefore,the prediction of reservoir production and transformation volume is particularly important for evaluating the effect of volume fracturing.However,at present,the prediction of the volume of reservoir production and transformation at home and abroad is mainly concentrated on the shale gas reservoir,and it is rarely used in the tight oil and gas reservoirs.Therefore,it is necessary to establish a reservoir for the tight sandstone stimulation volume prediction model and dynamic prediction model,impact assessment of formation parameters and construction parameters of stimulation volume and single well productivity.It is necessary to guide the fracturing design scientifically and improve the effect of fracturing.Based on a large number of domestic and international volume prediction models for reservoir reconstruction and tight gas reservoir production simulation,the volume prediction and productivity prediction simulation of the tight gas reservoir are systematically carried out.The main achievements are as follows:(1)Because of the theory of rock mechanics and seepage mechanics,based on natural random discrete fracture network model are derived and solved the two-dimensional model of the main crack extension and fracturing fluid flow model,combined with the failure criterion of natural fracture tension and shear,establishes reservoir stimulation volume prediction model;and on the basis of reasonable use of computer algorithm the tight gas reservoir reforming volume prediction simulation program,simulation and prediction of the overlapping failure zone volume is formed after the transformation(tensile failure and shear failure coexist),namely the reservoir stimulation failure zone.(2)The failure zone volume is formed after fracturing stress based on the calculation of the equivalent permeability damage sensitive grid full tensor using the principle of equivalent flow considering the tight gas reservoir was established based on this complex fracture network productivity prediction model,and gives a detailed derivation.The model fully considers the distribution of natural cracks and the influence of the fractured complex seams on fluid flow,and can adapt to various irregular fracturing networks.(3)The actual formation of the target block,cracks and the engineering parameters as the basis,using the reservoir stimulation volume prediction mathematical model to simulate the stimulation area,and analyzes the influence of block geological factors and engineering factors on SRV,and then the simulation result is equivalent to the existing production dynamic vertical permeability into good prediction and calculation of the corresponding model in dynamic production also,analyzed the influence of parameters and construction parameters on the yield of crack.Finally,the actual single well in the mine field is applied and analyzed,and the reasonable construction parameters are optimized.The research results in this paper have important guiding significance for volume fracturing evaluation and reconstruction of fractured tight sandstone reservoirs,which provides a new method for optimizing volume fracturing parameters and has great application prospects.