Now showing items 420-439 of 456

    • Target-oriented Time-lapse Waveform Inversion using Virtual Survey 

      Yang, Di; Zheng, Yingcai; Fehler, Michael; Malcolm, Alison E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
      Time-lapse seismic data are widely used for monitoring time-variant subsurface changes. Conventional analysis provides qualitative information by comparing results from consecutive surveys, whereas waveform inversion can ...
    • Temporal Integration of Seismic Traveltime Tomography 

      Ajo-Franklin, Jonathan B.; Urban, Jaime; Harris, Jerry M. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2005-06-01)
      Time-lapse geophysical measurements and seismic imaging methods in particular are powerful techniques for monitoring changes in reservoir properties. Traditional time-lapse processing methods treat each dataset as an ...
    • Theoretical Models Relating Acoustic Tube-Wave Attenuation To Fracture Permeability - Reconciling Model Results With Field Data 

      Cheng, C. H.; Tang, X. M.; Paillet, F . L. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)
      Several recent investigations indicate that tube-wave amplitude attenuation in acoustic full-waveform logs is correlated with permeability in fractured rocks. However, there are significant differences between predictions ...
    • Time Reversed Acoustics and Applications to Earthquake Location and Salt Dome Flank Imaging 

      Lu, Rongrong (Massachusetts Institute of Technology. Earth Resources Laboratory, 2008-02)
      The objective of this thesis is to investigate the applications of Time Reversed Acoustics (TRA) to locate seismic sources and image subsurface structures. The back-propagation process of the TRA experiment can be divided ...
    • A Time-Domain Finite-Difference Method With Attenuation By A Recursive Algorithm 

      Cheng, Ningya; Cheng, Arthur C. H.; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 1996)
      A recursive algorithm to incorporate attenuation into a time-domain finite-difference calculation is developed. First, a rheological model of the generalized Maxwell body is chosen. The discrete relaxation frequency and ...
    • Time-stepping beyond CFL: a locally one-dimensional scheme for acoustic wave propagation 

      Zepeda Nunez, Leonardo Andres; Hewett, Russell J.; Rao, Minghua Michel; Demanet, Laurent (Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
      In this abstract, we present a case study in the application of a time-stepping method, unconstrained by the CFL condition, for computational acoustic wave propagation in the context of full waveform inversion. The numerical ...
    • Toward The Simulation Of Attenuation: Oscillatory Flow In Porous Rock 

      Olson, John F. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1998)
      Fluid flow in porous rock due to an oscillatory pressure gradient is simulated. We observe distributions of density and velocity in the rock which point to viscous dissipation. We will use this method to seek a deeper ...
    • Towards a Quantitative Understanding of Bed Structure by Turbidity Currents 

      Kudrolli, Arshad; Blanchette, Francois; Brenner, Michael P.; Bush, John W. M. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2001)
      We are currently carrying out a series of experiments and theoretical calculations with the goal of creating a quantitative model for the structure of beds created by turbidity currents. Our research project operates on ...
    • Transient Fluid Flow In Heterogeneous Porous Media 

      Zhao, Xiaomin; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)
      A stable Alternating Direction Implicit finite-difference algorithm is used to model transient fluid flow in heterogeneous porous media. In connection with the laboratory system for pressure transient testing of core ...
    • Transverserly Isotropic Saturated Porous Formations: 1. Theoretical Developments And (Quasi) Body Wave Properties 

      Schmitt, D. P. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)
      Using the results of homogenization theory, the constitutive equations for an anisotropic porous formation saturated by a Newtonian viscous fluid are derived. The transverse isotropy situation is investigated in terms ...
    • Transverserly Isotropic Saturated Porous Formations: II. Wave Propagation And Application To Multipole Logging 

      Schmitt, D. P. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)
      The wavefields generated by monopole and dipole sources in a fluid filled borehole embedded in multilayered transversely isotropic saturated porous formations are studied. The layers are modeled following Biot theory ...
    • Tube Wave Attenuation and In-Situ Permeability 

      Hsui, Albert T.; Jinzhong, Zhang; Cheng, C. H.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)
      The measurement of in-situ permeability is very important in exploration and production logging. Observed data show that tube wave attenuation in full waveform acoustic logs is correlated with formation permeability. It ...
    • Tube Wave Generation At A Layer Boundary For An Incident Compressional Plane Wave 

      Peng, Chengbin; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)
      An approximate theory for the scattering of an incident plane P wave into tube waves in a fluid-filled borehole drilled through two homogeneous half-spaces is proposed in this paper. This theory is in excellent agreement ...
    • Tube Waves, Seismic Waves And Effective Sources 

      Burridge, Robert; Kostek, Sergio; Kurkjian, Andrew L. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1993)
      A simple asymptotic analysis, based on the smallness of the ratio of the borehole radius to the wavelength, reveals the interaction between tube waves and seismic waves. The pressure field in a tube wave acts as a secondary ...
    • Ultrasonic And Numerical Modeling Of Reflections From Simulated Fractured Reservoirs 

      Theophanis, Stephen; Zhu, Xiang (Massachusetts Institute of Technology. Earth Resources Laboratory, 1997)
      Vve examine seismic waves scattered from anisotropic heterogeneity with laboratory data and numerical modeling in order to develop modeling techniques for the characterization of fracture properties in tight gas sands ...
    • Ultrasonic Laboratory Study of Full Waveform Acoustic Logs in Boreholes with Fractures 

      Toksoz, M. N.; Guler, Fatih (Massachusetts Institute of Technology. Earth Resources Laboratory, 1987)
      A set of ultrasonic experiments was carried out to determine the effects of horizontal and vertical fractures on full waveform acoustic logs. Boreholes of 1 cm diameter were drilled in aluminum blocks. Measurements were ...
    • A unified Bayesian framework for relative microseismic location 

      Poliannikov, Oleg V.; Prange, Michael; Malcolm, Alison E.; Djikpesse, Hugues (Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
      We study the problem of determining an unknown microseismic event location relative to previously located events using a single monitoring array in a monitoring well. We show that using the available information about the ...
    • A unified framework for relative source localization using correlograms 

      Poliannikov, Oleg V.; Prange, Michael; Malcolm, Alison E.; Djikpesse, Hugues (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
      We study the problem of determining an unknown event location relative to previously located events using a single monitoring array in a monitoring well. We show that using the available information about the previously ...
    • Using Borehole Electroseismic Measurements To Detect And Characterize Fractured (Permeable) Zones 

      Mikhailov, Oleg V.; Queen, John H.; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 1997)
      We present a new type of field measurement capable of detecting and characterizing fractured (permeable) zones intersecting a borehole. The method is based on measuring electrical fields generated by a borehole Stoneley ...
    • Using Image Warping for Time-lapse Image Domain Wavefield Tomography 

      Yang, Di; Malcolm, Alison E.; Fehler, Michael (Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
      Time-lapse seismic data are widely used for monitoring subsurface changes. A quantitative assessment of how reservoir properties have changed allows for better interpretation of fluid substitution and migration during ...