Research On The Fracturing Fluid Flow Characteristics And Impact On The Reservoirs Fracture

Hydraulic fracturing technology is the one of the main measures, to increase the production of low permeability reservoir yield, currently. With the fracturing technology development and in-depth analysis of the effect of fracturing, People have gradually found that fracturing fluid is the main factors to the rock broken down and crack extension. Some hydraulic fracturing better, but some bad and even failure, one of the main reasons is that it is not clear enough to the flow characteristics of fracturing fluid through the fracturing pump and fracturing string. Not able to better predict the degree of fracturing fluid rheology changes which arrived the stratum. Thus it affects the hydraulic fracturing technology implementation successfully. So this paper do a depth study to the flow characteristics of fracturing fluid through the fracturing pump and fracturing string according to fluid dynamics theory. It layed a theoretical foundation to the effective development of low-permeability oil fields and the successful implementation of hydraulic fracturing technology.Fracturing pump,bend pipe and fracturing string are all the indispensability equipments and tools in the construction of hydraulic fracturing, and when the fracturing fluid flows down the equipments or tools by high speed and high pressure. It would have had a coupling effect of the force and displacement between the liquid and the solid. The paper set up a mechanical model of the pipe deformation and a dynamic model of the fracturing fluid, based on the theory of solid mechanics and fluid dynamics. And using the numerical simulation methods, it comes true the coupling interaction between the solid boundary and fluid, and get the rheological behavior of the fracturing fluid in the fracturing string. At the same time, the paper compared the calculation results with the test results of the pressure drop, when fracturing fluid flow in the straight pipe. The result is that the average residual rate is 2.93%, which prove validity of the theoretical analysis and calculation method. On the basis of that, the paper made an analysis to the change of the fracturing fluid viscosity and pressure drop, and the impact of volume on both.The ultimate aim of hydraulic fracturing is to squeeze a long and wide with a certain conductivity cracks. Based on rock mechanics,permeation mechanics,damage mechanics and fracture mechanics theory, the paper set up a low permeability reservoir hydraulic fracturing model, according to the finite element method, and on the basis of considering the fluid-solid coupling. Through the united use of N-R method and load incremental method, the paper got the dynamic expansion patterns of three-dimensional cracks in low-permeability reservoir, and analyzed the impact of fracturing fluid viscosity and the volume to the fracture morphology.With a wide range of low-permeability oil field development, to the effective implementation of hydraulic fracturing technology, it has very important significance to comprehensively and specifically study the impact of the fracturing fluid to fracturing effect. In considering the role of fluid-solid coupling conditions, the paper studied the rheological properties of the fracturing fluid which flow in the pipe, and which made the impact to the fracture morphology. It has an important significance to improve the oilfield hydraulic fracturing process design and enhance oil extraction rate.