The Design Of Casing Centralizer Reducing Friction Used In The Large Displacement Wells

For extended Wells and horizontal Wells,extreme casing pipes eccentricity caused by own gravity has been the main reason that affects whether the casing can go down to the borehole smoothly or not and can affect seriously the displacement efficiency of cement slurry.At last,it will affect seriously the cementing quality.On the current situation,the effective solution is installing casing centralizer in the proper position to improve the cementing quality.However,for the existing centralizers,no one can solve two problems very well.Therefore,designing extended wells casing centralizer is imminent in this paper.By researching literatures,this paper will analyze the existing casing centralizer structure characteristics,working principle,strengths and weaknesses.These will lay a foundation for designing the structure and principle of the casing centralizer.Ultimately I will design a spiral,many wings and universal wheels casing centralizer.For centralizer displacement efficiency,this paper will use vortex length as a measure of standard and build a model using ANSYS-fluent software to study.Some relations are obtained,including cross-sectional area of the flow guide vane,the length of centralizer body and flow guide vane,the effective height of centralizer body and flow guide vane,flow guide vane angle,annulus velocity and so on.And I have got the relations between the displacement efficiency and fluid performance parameter by Reynolds number.At last,fit out flow vortex length calculation formula.In this paper,I use the method of indoor small experiment and ANSYS numerical simulation to prove the design of casing centralizer,which can greatly reduce the friction resistance in the process of casing pipe.From considering of increasing the swirl fluid displacement efficiency and the casing deformation to reduce the casing friction resistance of,complement each other.Spacing distance is optimized and can meet improve cement slurry displacement efficiency and reduce the friction resistance of the process of casing setting using universal wheel casing centralizer.