Experiment Study of Flow Around Bypass Crossover Sub in Fracturing Process of Horizontal Wells LDA

The bypass crossover sub is important part of fracturing tube of horizontal wells,with increasing of fracturing flow rate,erosion of bypass crossover sub is increasingly serious.The flow field around bypass crossover sub is investigated by the Laser Doppler Anemometry(LDA) experiment.The velocity field have been measured.The experimental observations have shown that mean axial velocity at the slots on bypass crossover sub exist positive and negative values and the complex vortex exist.The backflow position and backflow rate of each profile are increasing different at different reynolds num.When the reynolds number increases to a value,the influence of gravity to flow field is very small.The pressure difference of inlet and outlet of experimental equipment is measured and the pressure coefficient of structure is calculated.All of these not only will provide some reference on the research of erosion and structural design and optimization,it also helps us better understand the turbulent flow mechanisms of a complex structure.