Browsing ERL Industry Consortia Technical Reports by Author "Cheng, N. Y."

Now showing items 1-6 of 6

    • Acoustic Logging In Randomly Stratified Formations 

      Tang, X. M.; Cheng, N. Y.; Cheng, C. H.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1993)
      The propagation of borehole acoustic waves in the presence of various types of heterogeneous formations is investigated by modeling them as stratified media with varying velocity-depth distributions. Two types of formations ...

    • Estimation Of Formation Parameters Using Full Waveform Acoustic and Shear Wave Logs 

      Cheng, N. Y.; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)
      A combination of borehole Stoneley waves from full waveform acoustic logs and direct shear wave logs was used to estimate formation permeability and shear wave velocity. Data sets used here were collected by Area's array ...

    • Experimental And Finite Difference Modelling Of Borehole Mach Waves 

      Cheng, N. Y.; Zhu, Zhenya; Cheng, C. H.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)
      A series of model experiments are done in the ultrasonic laboratory to study the radiation of downhole sources in a variety of formations. Three models are used in the experiments. They are a lucite model, a lucite model ...

    • Finite Difference Modelling Of Acoustic Logs In Vertically Heterogeneous Biot Solids 

      Stephen, Ralph A.; Cheng, N. Y.; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1987)
      This paper discusses the results of tests carried out on a finite difference formulation of Biot's equations for wave propagation in saturated porous media which vary in range and depth (Stephen, 1987). A technique for ...

    • Fourth-Order Finite Difference Acoustic Logs In A Transversely Isotropic Formation 

      Cheng, N. Y.; Cheng, C. H.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1993)
      In this paper we present a finite difference scheme for seismic wave propagation in a fluid-filled borehole in a transversely isotropic formation. The first-order hyperbolic differential equations are approximated ...

    • Inversion For Permeability From Stoneley Wave Velocity And Attenuation 

      Cheng, N. Y.; Cheng, C. H.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1990)
      The in situ permeability of a formation is obtained by the inversion of Stoneley wave phase velocity and attenuation, which are evaluated by applying the Extended Prony's method to the array sonic logging data. The Maximum ...