Study On Fracture Propagation Simulation And Fracking Parameters Optimization Of Tight Media

With the deep exploration of oil and gas resources,the unconventional oil and gas resources in tight media have become the hot spots of industry.The need for transformation by hydraulic fracturing in dense medium oil and gas reservoirs,but from the microscopic view,the characteristics of high pressure & high stress coupling rule of tight media reservoirs and the coupling effect of fracturing development and propagation of reservoir fracture are not clearly,which need for further research.In this paper,carbonate rock and shale are taken as examples of typical tight media.Based on the traditional Biot Theory and the Griffith-Coulomb fracture criterion,I established the fluid pressure and crustal stress coupling mathematics and mechanics model,and study the effect of coupling effect on fractures propagation in hydraulic fracturing process.The DEM is used for studying pressure-stress coupling law in the process of fracking in tight media from the microscopic view,influence mechanism and controlling factors of hydraulic fracture geometry were simulated and analyzed.The content of the research is applied to Tahe oil field as an example,the hydraulic fracturing construction parameters and process optimization of real reservoir distribution group,in order to overcome the influence of natural non continuous structure,initial stress on fracking to make complex network fracturing effect.The results showed that,the average particle size and particle size ratio will affect the shear strength of carbonate rock.The existence of the laminated structure can reduce the overall strength of the shale,and the bedding surface will be damaged first when the force(such as fluid pressure)is subjected.The mechanism of stress flow pressure coupling and its effect on the strength of dense medium rock are analyzed.The direct shear simulation of pore pressure in carbonate and non-bedding shale is carried out.It is proved that there is coupling between horizontal stress field and pore fluid.The hydraulic fracturing simulation of stratified shale and bedding shale has been carried out respectively.It is proved that there is a coupling effect between the horizontal stress field and the fracturing fluid.Based on Tahe oil field production data,use simulation method to study and optimization the hydraulic fracturing parameters of three wells,according to different reservoir distribution,respectively study the fracturing fluid viscosity,injection rate and other parameters such as the influence of blasting induced fracturing process on the fracturing operation,optimization and the construction parameters.