Now showing items 1-18 of 18

    • 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, ...
    • Comparison of microearthquake locations using seismic interferometry principles 

      Melo, Gabriela; Malcolm, Alison E.; Fehler, Michael (Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
      Mapping, localization, and general characterization of problems in reservoir fracture systems is one of the most important in oil, gas, and geothermal energy production. One way to study and monitor these fracture systems ...
    • Detecting medium changes from coda by interferometry 

      Poliannikov, Oleg V.; Malcolm, Alison E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)
      In many applications, sequestering CO[subscript 2] underground for example, determining whether or not the medium has changed is of primary importance, with secondary goals of locating and quantifying that change. We ...
    • Finite-Difference Simulations of Time Reversed Acoustics in a Layered Earth Model 

      Lu, Rongrong; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 2007)
      Traditionally an earthquake is located by using the arrival times of P and S phases. This uses only a limited portion of the information on a seismogram. A large part of the information carried by the waveform is not used. ...
    • Imaging Salt Dome Flank and Dipping Sediments Using Time Reversed Acoustics 

      Lu, Rongrong; Willis, Mark E.; Campman, Xander; Ajo-Franklin, Jonathan B.; Toksoz, M. Nafi (Massachusetts Institute of Technology. Earth Resources Laboratory, 2006)
      In this paper we define the theory and basic principles to move (redatum) the surface shots from a walk away VSP to be as if they had been located in the borehole. We will refer to this theory using several of the terms ...
    • Improved Green’s functions from seismic interferometry 

      Poliannikov, Oleg V.; Willis, Mark E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2008-06-16)
      Under certain theoretical assumptions, the theory of seismic interferometry allows the construction of artificial (or virtual) sources and receivers at the locations of receivers in a physical experiment. This is done ...
    • Interferometric correlogram-space analysis 

      Poliannikov, Oleg V.; Willis, Mark E.; Mashele, Bongani Jabulani (Massachusetts Institute of Technology. Earth Resources Laboratory, 2009-05-31)
      Seismic interferometry is a method of obtaining a virtual shot gather from a collection of actual shot gathers. The set of traces corresponding to multiple actual shots recorded at two receivers is used to synthesize a ...
    • Interferometric correlogram-space analysis 

      Poliannikov, Oleg V.; Willis, Mark E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010-04-26)
      Seismic interferometry is a method of obtaining a virtual shot gather from a collection of physical shot gathers. The set of traces corresponding to two common receiver gathers from many physical shots is used to synthesize ...
    • Interferometric hydrofracture microseism localization using neighboring fracture 

      Poliannikov, Oleg V.; Malcolm, Alison E.; Djikpesse, Hugues; Prange, Michael (Massachusetts Institute of Technology. Earth Resources Laboratory, 2011-05-19)
      Hydraulic fracturing is the process of injecting high-pressure fluids into a reservoir to induce fractures and thus improve reservoir productivity. Microseismic event localization is used to locate created fractures. ...
    • Interferometric imaging of multiples in an RTM approach 

      Malcolm, Alison E.; de Hoop, Maarten V. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)
      It is well known that reverse-time migration is capable of correctly imaging multiply scattered energy. To do this, one of the interfaces from which the waves scatter must be included in the background velocity model. ...
    • Kinematic redatuming by two source interferometry 

      Poliannikov, Oleg V. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010-04-26)
      Interferometry is a method of redatuming physical sources to receiver locations. Under idealized assumptions stacking the cross correlogram of the two common receiver gathers yields a bandlimited Green's function between ...
    • Microquake seismic interferometry with SVD enhanced Green's function recovery 

      Melo, Gabriela; Malcolm, Alison E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)
      The conditions under which seismic interferometry (SI) leads to the exact Green’s function (GF) are rarely met in practice, resulting in errors in the recovered GF. To alleviate this problem, we employ additional information ...
    • A Novel Application of Time Reversed Acoustics: Salt Dome Flank Imaging Using Walkaway VSP surveys 

      deHoop, Maarten V.; Willis, Mark E.; Lu, Rongrong; Campman, Xander; Toksoz, M. Nafi; e.a. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2006-03-01)
      In this paper we present initial results of applying Time-Reversed Acoustics (TRA) technology to saltdome flank, seismic imaging. We created a set of synthetic traces representing a multilevel, walkaway VSP for a model ...
    • SVD enhanced seismic interferometry for traveltime estimates between microquakes 

      Melo, Gabriela; Malcolm, Alison E. (Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)
      In general, Green’s functions obtained with seismic interferometry are only estimates of the true Green’s function, introducing uncertainties to the information recovered from them. However, there are still many cases in ...
    • 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 ...
    • 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 SVD for improved interferometric Green's function retrieval 

      Melo, Gabriela; Malcolm, Alison E.; Mikesell, Dylan; van Wijk, Kasper (Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
      Seismic interferometry (SI) is a technique used to estimate the Green’s function (GF) between two receiver locations, as if there were a source at one of the receiver locations. However, in many applications, the requirements ...
    • Using SVD for improved interferometric Green’s function recovery. 

      Melo, Gabriela; Malcolm, Alison E.; Mikessel, Dylan; van Wijk, Kasper (Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)
      Seismic interferometry is a technique used to estimate the Green’s function (GF) between two receiver locations, as if there were a source at one of the locations. By crosscorrelating the recorded seismic signals at the ...