ACCURACY OF THE BOUNDARY CONDITIONS AT THE UPPER TANGENT OF THE CONVENTIONAL BHA

The boundary conditions at the upper tangent of the conventional bottom hole assembly can be expressed as: 1. Contacts the lower side of the bore wall; 2. The corner angle conforms to the hole axial line; 3. The curvature conforms to the hole axial line. This expression has been used for years with no problem, yet some paper at home denies it lately. The accuracy of the boundary conditions expression is illustrated and proved in this paper.