The Simulation Of Acoustic Logging Tool In Viscoelastic

Acoustic logging is an important and general method in oil exploration. The reaserch of the wave propagation in oil exploration come down to slove the acoustic field in cylindrical formation . This is one of the basic subjects in acoustic. The elastic wave in elastic solid has been studied widly,but the reaserch on the viscoelastic is not enough. Now there are two methods. One is binging in the qulity factor and the second is complex modulus which is also called viscoparameter. In the reaserch of earthquake simulation ,people often adopt the Q method. In the reaserch of oil logging people often adopt complex modulus. Are there differences when the two methods used in oil logging. This promblm is not studied before. So the main content of this article is following:Firstly, on the foundation of elastic acoustic flied ,the article solve the viscoproblem by two methods.After getting the full acoustic flied function, the article discusses their differences.Sencondly, the article adopts complex frequency domain method in numberic simulation, analyses the poles of the acoustic function, choose the envelope-cosine as the source,uses the Fortran 90 and finally get the curves of the full wave. The article compares the two methods in oil logging. Find out that the rudius, distance, frequency and the visco-parameters have important impact on the cures.