Study On Drag Reduction Characteristics And Models Of Slickwater Fracturing Fluid

Drag reduction performance is the most important technical indicator of slickwater,the accurate estimation of fracturing friction is critical to the design of construction displacement.In a variety of drag reduction performance evaluation programs,commonly using the loop friction test to achieve the optimal choice of related products,but the test data is difficult to repeat in other experimental platforms.It is rare to see how the evaluation results are applied to the field.In order to obtain accurate friction data,it is optimized to establish an indoor loop friction test system,which can switch the pipe diameter,monitor the flow and maintain the temperature.The experimental power source uses a screw pump with a maximum displacement of 2.5 m~3/h.Before evaluation and testing,based on the Prandtl-Karman law,the diameters of three testing straight pipes were calibrated through the water turbulence experiments,and their diameters are 10.46 mm,7.59 mm and 5.86 mm,respectively.The parallel experiments are carried out by this platform.Through the drag reduction performance test and the shear resistance test,the best DR800 was selected from 5 kinds of drag reduction agents.Through refinement experiments,the factors affecting drag reduction are analyzed,such as displacement,diameter,concentration and temperature.The optimal flow parameters describing the drag reduction rate are determined as the Reynolds number,and the concentration of the field is 0.08%.Both concentration and temperature effects can be associated with viscosity changes.Through the comparison between the historical engineering data and the results of the 6 kinds of clear water models,it is concluded that the Barr formula is the best.The value of absolute roughness has a significant influence on the result.The value of Xinjiang is 0.012mm,and the value of Changqing is 0.0013mm.Substituting the laboratory data into 4 kinds of slickwater drag reduction models,fitting to determine the correlation coefficients.By comparing with field fracturing data,two models for calculating friction coefficients directly have better prediction effect,and they all consider the effect of the viscosity term on the calculation of the Reynolds number.Based on the indoor and outdoor data sets,the recommended non-Newtonian fluid model coefficients are adjusted,and the calculation software suitable for field engineering parameters is formed.This paper can be used as a reference for the experimental study of slickwater and the study of model.It is of great significance to the field application of drag reduction agent.