Diffraction of waves by bed boundaries in an open borehole.

The diffraction of fields and waves by an open geometry which has a mixture of vertical and horizontal boundaries is solved with a semi-analytic approach. This is an unsolved problem except with the finite element method. The axial symmetric cases with both TE and TM polarizations are presented here. The method is about 100 to 200 times faster than the finite element method. The approach is to divide a composite boundary value problem into regions. The eigenfunctions in each region are sought numerically, and the total solution to the problem is obtained by matching boundary conditions at the boundary.-Authors