Now showing items 21-40 of 456

    • Analysis of location uncertainty for a microearthquake cluster: A case study 

      Melo, Gabriela; Malcolm, Alison E.; Poliannikov, Oleg V.; Fehler, Michael (Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
      In many reservoirs, an increase in permeability and conductivity is achieved by hydraulic fracturing/stimulations which open cracks and fractures that then act as pathways for fluids to navigate in the subsurface. Mapping, ...
    • Analysis Of Microseismic Location Accuracy For Hydraulic Fracturing At The DWTI Site, Jasper, Texas 

      Rieven, Shirley; Rodi, William (Massachusetts Institute of Technology. Earth Resources Laboratory, 1995)
      This report presents the results of a feasibility study designed to assess whether microseismic location techniques can provide enough accuracy and precision to enable a high resolution study of the spatial distribution ...
    • Analysis of Scattered Signal to Estimate Reservoir Fracture Parameters 

      Grandi, Samantha K.; Willis, Mark E.; Burns, Daniel R.; oksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 2007-05)
      We detect fracture corridors and determine their orientation and average spacing based on an analysis of seismic coda in the frequency-wave number (f-k ) domain. Fracture corridors have dimensions similar to seismic ...
    • Anisotropic Perfectly Matched Layers for Elastic Waves in Cartesian and Curvilinear Coordinates 

      Zheng, Yibing; Huang, Xiaojun (Massachusetts Institute of Technology. Earth Resources Laboratory, 2002)
      We develop new numerical anisotropic perfectly matched layer (PML) boundaries for elastic waves in Cartesian, cylindrical and spherical coordinate systems. The elasticity tensor of this absorbing boundary is chosen to be ...
    • Annual Report 2012 Table of Contents 

      Massachusetts Institute of Technology. Earth Resources Laboratory (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
    • Application of Full Waveform Acoustic Logging Data to the Estimation of Reservoir Permeability 

      Mathieu, F.; Toksoz, M. N. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)
      Development of borehole geophysics has recently focused on reservoir characterization. Within this effort, extensive full waveform acoustic surveys have demonstrated a correlation between the occurance of open fractures ...
    • Application Of Rayleigh's Principle To Guided Waves In A Borehole 

      Ellefsen, K. J.; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)
      The Lagrangian for guided waves in a completely general borehole model is presented. Rayleigh's principle is used to derive the first order perturbations in wavenumber and frequency due to slight perturbations in the ...
    • Application Of Smooth Neural Networks For Inter-Well Estimation Of Porosity From Seismic Data 

      Saggaf, Muhammad M.; Toksoz, M. Nafi; Mustafa, Husam M. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2000)
      We apply an approach based on smooth neural networks to a 3D seismic survey in the Shedgum area of the Ghawar Field to estimate the reservoir porosity distribution of the Arab-D Member. We conducted numerous systematic ...
    • Applications of Finite Difference Synthetic Acoustic Logs 

      Stephen, R. A.; Pardo-Casas, F. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)
      Finite difference synthetic acoustic logs are suitable for studying wave propagation in vertically varying boreholes and in boreholes with continuously varying properties. Snapshots for the traditional smooth bore in a ...
    • Applications Of Perturbation Theory To Acoustic Logging 

      Ellefsen, K. J.; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)
      For guided wave propagation in boreholes, perturbation theory is used to calculate (1) the partial derivative of the wavenumber or frequency with respect to an elastic modulus or density, (2) group velocity, and (3) the ...
    • Applying Compactness Constraints to Differential Traveltime Tomography 

      Ajo-Franklin, Jonathan B.; Minsley, Burke J.; Daley, Thomas M. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2007)
      Tomographic imaging problems are typically ill-posed and often require the use of regularization techniques to guarantee a stable solution. Minimization of a weighted norm of model length is one commonly used secondary ...
    • Applying Compactness Constraints to Seismic Traveltime Tomography 

      Ajo-Franklin, Jonathan B.; Minsley, Burke J.; Daley, T. M. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2006)
      Tomographic imaging problems are typically ill-posed and often require the use of regularization techniques to guarantee a stable solution. Minimization of a weighted norm of model length is one commonly used secondary ...
    • An approach for predicting stress-induced anisotropy around a borehole 

      Fang, Xinding; Fehler, Michael; Zhu, Zhenya; Chen, Tianrun; Brown, Stephen; e.a. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
      Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could result in a biased estimation of formation properties but could provide ...
    • Approximate Effects of Off-Center Acoustic Sondes and Elliptic Boreholes Upon Full Waveform Logs 

      Willis, M. E.; Toksoz, M. N.; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)
      Full waveform acoustic well logging has become instrumental to hydrocarbon exploration because of its ability to determine in situ velocity information for P and S waves as well as the attenuation (or absorption) of seismic ...
    • Approximate inversion of the wave-equation Hessian via randomized matrix probing 

      Letourneau, Pierre-David; Demanet, Laurent; Calandra, Henri (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
      We present a method for approximately inverting the Hessian of full waveform inversion as a dip-dependent and scale-dependent amplitude correction. The terms in the expansion of this correction are determined by least-squares ...
    • Array-conditioned deconvolution of multiple component teleseismic recordings 

      Chen, C. -W.; Rondenay, Stephane; Miller, D. E.; Djikpesse, H. A. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010-01-01)
      We investigate the applicability of an array-conditioned deconvolution technique, developed for analyzing borehole seismic exploration data, to teleseismic receiver functions and data preprocessing steps for scattered ...
    • Asymmetric Modes of Elastic Wave Propagation in a Fluid-Filled Borehole 

      Jinzhong, Zhang; Cheng, C. H. (Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)
      A numerical investigation of asymmetric modes of elastic wave propagation in a fluid-filled borehole is treated in this paper. The dispersion curves of guided waves (called flexural waves) and synthetic microseismograms ...
    • Asymmetric source acoustic LWD for the improved formation shear velocity estimation 

      Chen, Tianrun; Wang, Bing; Zhu, Zhenya; Burns, Daniel R. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2009)
      Most acoustic LWD tools generate a single pure borehole mode (e.g., dipole or quadrupole) to estimate the formation shear velocity. We propose an approach where many borehole modes are generated and all the modes are ...
    • Asymmetric source acoustic LWD for the improved formation shear velocity estimation 

      Chen, Tianrun; Wang, Bing; Zhu, Zhenya; Toksoz, Daniel R. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)
      Most acoustic logging while drilling (LWD) tools generate a single pure borehole mode (e.g., dipole or quadrupole) to estimate the formation shear velocity. We propose an approach where multipole modes are generated ...
    • AVO Monitoring of CO[subscript 2] Sequestration 

      Brown, Stephen; Hagin, Paul; Bussod, Gilles (Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)
      Standard geophysical methods for monitoring CO[subscript 2] injection have been proposed but many have severe limitations. In particular, while they can be used to monitor the presence or absence of CO[subscript 2] during ...