We estimate shear-wave velocities in the shallow subsurface throughout Japan by applying seismic interferometry to the data recorded with KiK-net, a strongmotion network in Japan. Each KiK-net station has two receivers; one receiver on the surface and the other in a borehole. By using seismic interferometry, we extract the shear wave that propagates between these two receivers. Applying this me...

To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 6...

In a fluid-saturated porous formation, an impinging seismic wave induces fluid motion. The motion of fluid relative to the rock frame generates an electric streaming current. This current produces electric and magnetic fields, which are called seismoelectric and seismomagnetic fields, respectively. When there is a fracture or a discontinuity, a radiating electromagnetic wave is also generated, ...

In the context of deep geological disposal of high level radioactive wastes, the French National Radioactive Waste Management Agency (Andra) has conducted an extensive characterization of the Callovo-Oxfordian argillaceous rock and surrounding formations in the Eastern Paris Basin. For such characterization, a detailed 3D geological model is needed. This paper shows the procedure used for build...

We simulate electromagnetic (EM) measurements obtained by using one transmitter and one receiver antenna in a borehole environment. The measurements are used to assess electrical properties of rock formations. We have started from a problem where logging instruments as well as rock formation properties are assumed to exhibit axial symmetry around the axis of a vertical borehole. The initial com...

This paper presents a study on pseudo-analytic techniques for modeling electromagnetic sensors used in geophysical well logging. Logging-while-drilling (LWD) tools are typically the exploration of hydrocarbons reservoirs and usually immersed complex formations (inhomogeneous, dissipative, anisotropic), resulting challenging problem conventional computational techniques. The environment is treat...

[1] The primary goal of the Ocean Seismic Network Pilot Experiment (OSNPE) was to learn how to make high quality broadband seismic measurements on the ocean bottom in preparation for a permanent ocean seismic network. The experiment also had implications for the development of a capability for temporary (e.g., 1 year duration) seismic experiments on the ocean floor. Equipment for installing, op...

In shear wave far detection logging, dipole-source radiation is the main factor influencing amplitude of reflected waves. this paper, a method derived with far-field asymptotic solution to calculate waves in fluid-filled borehole. Then simulated under both low and high frequencies. addition, influences formation elastic parameters on are analyzed variations characteristics source frequency bore...

The correct positioning of deep wells to monitor groundwater and entrained contaminants is greatly aided by using remote sensing methods. The geologic setting at the Anniston Army Depot (ANAD) consists of a sequence of fractured dolostones and clastic rocks that have been thrust-faulted, creating a highly complex and heterogeneous aquifer. The drilling of deep bedrock groundwater monitoring wel...

A new method based on generalized reflection and transmission coefficients is proposed to calculate the synthetic seismograms in radially multilayered media. This method can be used to efficiently simulate full waveform acoustic logs and crosswell seismic profiles in situations where we need to consider borehole effects. The new formulation is tested by comparing our numerical results with prev...