a large distribution of pore sizes, ranging from microcrystalline to large vugs. Knowledge of these pore spaces and their connectivity is crucial to hydrocarbon reservoir characterization and to hydrogeological and near surface environmental applications. In this paper, we present permeability and porosity images based on crosswell seismic measurements integrated with well logs and petrography ...

in the form of passive seismic methods, broadband seismometers have been used in hydrocarbon exploration. the frequency bandwidth typically studied is in the range of 1–6 hz. the observations on low frequency band of microtremors are used to calculate the spectral ratio of vertical and horizontal components (v/h) and power spectral density (psd). attributes based on the v/h ratio and the psd ha...

The sonic-waveform processing and imaging flow presented in this paper uses fullwaveform data recorded with a conventional acoustic well-logging tool, then adapts known surface-seismic processing steps and optimizes them for the borehole environment. This paper presents improvements brought to our original sonic-waveform processing and imaging flow. These improvements are better geometry assign...

The virtual source method has been applied successfully to retrieve the impulse response between pairs of receivers in the subsurface. This method is further improved by an updown separation prior to the crosscorrelation to suppress the reflections from the overburden and the free surface. In a reversed situation where the sources are in the subsurface and receivers are on the surface, in princ...

The electrokinetic effect in a fluid-saturated porous rock is defined as the coupling and conversion between seismic and electric energies. When seismic waves propagate through a fluid-saturated formation and cause a pore fluid-flow relative to the solid matrix, the motion of the cations in the fluidflow forms a streaming electrical current and induces an electromagnetic wave at any discontinuo...

Tremendous efforts have been devoted to improve our understanding of the anthropogenic effects on the atmospheric temperature change. In comparison, little has been done in the study of the human impacts on the subsurface thermal environment. The objective of this study is to analyze surface air temperature records and borehole subsurface temperature records for a better understanding of the ur...

Although synthetic borehole seismograms routinely can be computed for a wide range of borehole conditions, the physical nature of shear and compressional head waves in fluid-filled boreholes is poorly understood. This paper presents a series of numerical experiments designed to provide insight into the physical mechanisms controlling head wave propagation in boreholes. These calculations demons...

238 C geophysical methods are increasingly used to estimate hydrogeologic properties of the unsaturated zone. Th ese methods provide high-resolution in situ information for large support volumes of the subsurface with minimal intrusion and thereby have obvious advantages over other more traditional methods such as neutron probe and time domain refl ectrometry. In particular, cross-borehole elec...

An integrated suite of geophysical methods was used to characterize the hydrogeology of a fractured-rock aquifer to identify contamination or pathways for contaminant migration near a former landfill at the University of Connecticut, Storrs, Connecticut. Surface-geophysical methods were used to identify the dominant direction of fracture orientation and to locate potential leachate plumes. Two ...

BACKGROUND In arid systems with no surface water, deep boreholes in ephemeral river beds provide for humans and animals. With continually increasing infrastructure development for tourism in arid wildlife parks such as the Kgalagadi Transfrontier Park in southern Africa, we ask what effects increased abstraction may have on large trees. Large trees in arid savannas perform essential ecosystem s...