Effect of Wear of Cylindrical PDC Cutting Teeth on Drilling Process
Polycrystalline diamond compact(PDC)bits are a common choice for deep drilling operations involving oil,gas,and geothermal wells.Their high wear resistance and drilling efficiency make them an optimal choice for such applications.The performance of PDC cutting teeth is dependent upon the degree of cutting tooth wear,which in turn affects the wear of the drill bit and the efficiency of the drilling process.Consequently,the study of cutting tooth wear is of paramount importance to the formulation of regulations pertaining to the machining process.To address the issue of calculating the complex shape and difficult areas of contact between cutting teeth and rock during the wear stage,a method utilizing a planar oblique section of the cylindrical surface where the composite piece is located was employed.This approach yielded the conclusion that the contact area is a partial ellipse and led to the derivation of a functional expression for the wear height,back rake angle,and contact area.Furthermore,the impact of alterations in wear height and back rake angle on contact specific pressure and intra-chip shear stress was examined.The results demonstrate that the contact area between the cutting teeth and the rock is influenced by the wear height and back rake angle of the composite piece.As the wear height increases,the back inclination angle decreases,resulting in an enlarged contact area and a higher area change rate.Consequently,the contact-specific pressure and the chip under the same load exhibit a downward trend as the contact area expands.Accordingly,the optimal drilling process parameters should be selected in accordance with the wear state of the PDC cutter in order to maintain the rock-breaking efficiency of the PDC drill bit.
PDC cutting teethwear heightcontact areaweight on bitshear stress
万方数据
维普
