... ABSTRACT In downhole microseismic measurement, head waves (or refracted waves) instead of direct waves can be recorded as first arrivals under limited conditions. The head waves have been generally regarded as a nuisance in microseismic analysis including microseismic event localization...

... Summary In this paper, we show that the location of microseismic events can be significantly improved by incorporating information on head wave arrival time. The traditional method of using direct arrival times and P-wave polarizations leads to increased error due to the large uncertainty...

... traveltime tomography solver. Using information contained in the packets, we can correctly model head waves, and diving waves. The workflow is fully automated and can be used for in a batch processing environment with minimum human intervention. We demonstrate the method with two synthetic examples and one...

... of a three-well microseismic survey in the Mont- ney formation in Alberta was performed in 2012 by Octave Reservoir Technologies using a proprietary technique known as multipath analysis. Simultaneous detection and analysis of direct-path and head-wave arrivals of microseismic event en- ergy during...

..., which include reflections and head waves, have traditionally been viewed as a nuisance in microseismic analysis, potentially causing additional false-positive event detections and erroneous localizations into the layers which generate them. In particular, the effects and potential use of head waves...

... inhomogeneous structures, the differential solution (FD) is preferred over the integral solutions (RSW and reflectivity). amplitude incidence angle rsw src reflection coefficient pva wavelet reflectivity geophysics reflection upstream oil & gas head wave reflectivity method cervený...

... from the source position, and so prevents accurate picking of traveltimes in far-offset traces. To enhance the signal-to-noise ratio of the far-offset traces, we present the theory of super-virtual refraction interferometry where the signal-to-noise ratio (SNR) of far-offset head-wave arrivals can...

... field in the North Sea. The predicted velocity change using this method matches qualitatively the velocity changes predicted from an independent acoustic impedance study and the synthetic data reasonably well. overburden p-wave velocity upstream oil & gas head wave acoustic impedance...

... in different seismic applications mostly based on the reflected P- and S- waves. The first attempt to expand the VSM to head waves was done by Tatanova et. al. (2007) in order to assess its feasibility for reservoir monitoring. It was shown that a head wave between the virtual source and the receivers could...

...Reconstructing head waves with Virtual source method Maria Tatanova*, Saint-Petersburg State University; Andrey Bakulin, Shell International E & P; Kurang Mehta, Shell International E & P; Valeri Korneev, Lawrence Berkeley National Laboratory; Boris Kashtan, Saint-Petersburg State University...

... of reasons to expect even better results when head waves are restored and used for reservoir imaging and monitoring purposes. Being compared with a reflection survey, the head waves have less strict requirements for surface sources placements providing data for high resolution tomographic image...

... ABSTRACT The theory and practice of refraction interferometry is presented. We show that the crosscorrelation between a nearby pair of refraction traces yields a head wave event kinematically equivalent to one generated by a source at position x along the refractor. This redatumed source...

... inference that no critically refracted shear arrivals (called shear head wave hereafter) existed in a borehole embedded in soft formation. However, in this paper we would demonstrate by numerical simulations and field examples that a low-frequency and localized acoustic source regardless of its order...

...Head Waves as Mechanism for Azimuthal PP AVO Magnitude Anomalies Julius Doruelo*, Fred Hilterman and Gennady Goloshubin, CAGE Consortium, Department of Geosciences, University of Houston Summary We performed physical seismic modeling experiments to simulate seismic reflections off the top...

... the true envelope (absolute amplitude of the analytic signal). It was constructed using a partial implementation of the reflectivity method that computes the exact waveforms of the primary reflections and associated head waves (i.e., refractions along the interfaces). Figure 1b was created by means...

... houston 2005 head wave receiver upstream oil & gas processing algorithm attenuation analysis modeling wavelet algorithm petrophysics borehole reflection well log Attenuation analysis and modeling of acoustic waveforms in borehole intercepted by a sand- shale sequence J. O. Parra*, C. L...

... Summary Conventional reflection seismology is often insensitive to hardrock property variations and therefore ineffective in detecting hardrock reservoirs. In contrast, horizontally traveling waves such as head waves and diving waves can probe hardrock formations for long distances...

.... In this case, the main component of the monopole waveforms is a borehole mode, dispersive, which propagates at the mud slowness. The compressional head wave vanishes because the energy is refracted away. Under these circumstances, when using conventional procedures, the compressional slowness log reads the mud...

... about head waves. The comparison of finite-difference solutions of the elastic wave equation with the eikonal solver demonstrate that the method developed here can provide correct first arrival traveltime information. Introduction The finite difference(FD) approximation to the eikonal equation...

... san antonio velocity layer boundary wave field upstream oil & gas seismogram high velocity layer head wave propagation Generation of radial waves recorded at seafloors in the presence of a thin high velocity layer Chen Yao, Institute of Geology CSB, China; Xiangguo Chen, Institute...