The Research On Electromagnetic Wave Resistivity MWD Tool's Numerical Simulation Method

With the improvement of measurement accuracy and reliability, electromagnetic resistivity wave logging while drilling technology have become an increasing concern. In recent years, electromagnetic resistivity wave logging while drilling technology and its related technology has developed rapidly, applications are expanding., especially in the areas of drilling and reservoir evaluation ,so the prospect is bright. Researching on electromagnetic resistivity wave logging while drilling response of numerical simulation method,which is important to the development of electromagnetic wave resistivity measuring-while-drilling tool.In the paper, the 2D integral equations are computed by an integrated iteration algorithm of modified successive approximation method (MSAM) and Aitken acceleration technique. And the response of electromagnetic resistivity wave logging while drilling.including theoretical algorithm derivation, building physical model,programming calculation ,logging response. And the achievements are obtained as following:Firstly, the dyadic and improve of modified successive approximation method (MSAM) calculate the response of electromagnetic resistivity wave logging while drilling, The longitudinally stratified virgin formation is taken as the background and the computational region is restricted within the borehole and invasion zone in the algorithm, thus the algorithm is qualified for the virtues of small number of unknowns, fast converging speed and high accuracy. Secondly, this method program of electromagnetic resistivity wave logging while drilling is compiled on the Fortran power station4.0 software , the logging respone plot on different conditions can be discribed amplitude attenuation and phase shift of the apparent resistivity curve. Finally,in the source frequency of 2MHz and circumstances specific spacing ,the influencing regularity of electromagnetic logging response while drilling are simulated in layered formation considering thickness, rock , borehole and invasion, which is stratigraphic interpretation and evaluation of important reference value for the further.