Experimental Study On The Helical Turbulent Flow Of Power Law Fluid In Eccentric Annulus With PIV Technology

In oil industry, the helical flow of power law fluid in eccentric annulus is extremely commen, turbulent flow is one of the most common flow conditions. Generally, in oil well drilling, the flow of drill fluid in drill pipe and drill collar is turbulent flow, for the flow of drill fluid in annulus, sometimes it is laminar flow and sometimes it is turbulent flow. With the development of science and the request of project application, it greatly accelerated the progress of turbulent research, but turbulent flow itself is an extremely complex flow condition with strong randomness, conspired with the nonlinear of power law pattern, the asymmetry of eccentric annulus, the complexity of helical flow and the limitations of flow field's testing technology, so far, nobody has researched the helical turbulent flow of power law fluid in eccentric annulus, some relevant project problems are still hard resolved. The advent of PIV technology provided us with more efficient means for understanding the inner situation of flow field thoroughly, so this paper developed experimental study on the helical turbulent flow of power law fluid in eccentric annulus with PIV Technology.In view of the research subject, this paper established a set of device of vertical annulus pipeline that the eccentricity was adjustable, to research helical turbulent flow law of power law fluid in annulus line. PIV experiments of water and polymer water solution were carried out separately, obtained velocity vector, flowline, velocity contour and situation of axial velocity distribution in annulus when inner tube is motionless and cicling. Established a new discriminant method of flow pattern——by velocity contours, and analysed affecting factors and affecting laws of axial velocity distribution, pressure gradient and flow condition, discovered features and occuring process of helical turbulent flow of power law fluid in eccentric annulus from velocity contours.This paper proved the feasibility of PIV technology for the research of helical turbulent flow of power law fluid in eccentric annulus, the view is proposed innovately, supplied thinking for experimental study of other fluid's flow law, the experimental results of this paper will be of certain reference value to theory research and field application.