Study On Well Test Analysis Model Of Fractured Well In Tight Gas Reservoir

As a very important unconventional oil and gas resource,tight gas has abundant reserves in China.The reasonable and efficient development of tight gas reservoir is very important to ensure the energy security and reduce the dependence on foreign countries.Because of its special gas reservoir properties,it is necessary to obtain considerable industrial oil and gas flow through hydraulic fracturing.Therefore,the study of the percolation theory and well test model of fracturing wells plays an important role in analyzing the production performance and well test interpretation of tight gas wells.According to the well test model of fracturing well in tight gas reservoir,considering the stress sensitivity,which is the unique seepage characteristics of uniform dense gas reservoir,this paper establishes the vertical well model of uniform medium fully open fracturing,dual medium fully open fracturing,uniform medium partially open fracturing,dual medium partially open fracturing,uniform medium multi-stage fracturing horizontal well model and dual medium multi-stage fracturing horizontal well model Type.According to the equation characteristics of each model,using Laplace transform,Fourier transform,Duhamel principle,perturbation method and Stehfest numerical inversion,using the idea of point source function and line sink,the bottom hole pressure response solutions of each medium and well type in tight gas reservoir are obtained,and the typical double logarithm curves are calculated by MATLAB language.According to the curve characteristics,the convection sections are divided and analyzed The influence of reservoir parameters and fracturing operation parameters on the curve.The following work has been completed:(1)The stress sensitive effect of tight gas reservoir different from common gas reservoir is analyzed,and the calculation formula of fracture permeability stress sensitive index is determined,which lays a foundation for well test analysis model.(2)According to the theory of unsteady flow,a vertical well test model of full injection fracturing for tight gas reservoir with stress sensitive effect under uniform medium and dual medium is established.The bottom hole pressure response and typical double logarithm curve are obtained by using a variety of mathematical and physical methods based on the idea of line aggregation(3)The idea of point source function is adopted,and the consideration stress under uniform medium and dual medium is established The vertical well test model of partial injection fracture in tight gas reservoir with force sensitive effect is established,and the typical double logarithm curve is drawn.(4)A multi-stage fracturing horizontal well model of tight gas reservoir with stress sensitive effect in uniform medium and dual medium is established.Through numerical discretization of fractures,the bottom hole pressure response is obtained.(5)The sensitivity parameters of basic geological parameters and fracturing construction parameters of each model are analyzed,and the effect of stress sensitive effect on typical double logarithm curve is mainly considered.The work of this paper has important guiding significance for the interpretation of multi data fine well test of fractured wells in tight gas reservoir and the recognition of the pressure double logarithm curve measured on site.