With the rapid growth of economy and population, desire to use groundwater supplies is increasing. In order detect groundwater, conducting a geophysics survey common way map subsurface. This method can describe subsurface’s physical properties. For example, direct current (DC) resistivity provides subsurface, in which normally located low anomaly zones. However, DC needs overcome challenges urb...

As one of the most sensitive instruments for deformation monitoring in geophysics, borehole strainmeter has capability to record a large spectrum tectonic and environmental signals. Sensors are usually deployed near active faults volcanoes provide high-resolution continuous recordings seismic aseismic signals, hydrological variations (rainfall, groundwater level) natural hazards (tropical cyclo...

Borehole waves are strongly affected by adjacent porous zones or by fractures intersecting the borehole. A theoretical description for both porous and fracture zones is possible based on the introduction of an effective borehole fluid bulk modulus, characterizing the wave attenuation via borehole wall impedance. This impedance can be calculated for both porous and fracture zones adjacent to the...

Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This can lead to an incorrect estimation of formation elastic properties measured from sonic logs. Previous work has focused on estimating the elastic properties of the formation surrounding a borehole under anisotropic stress loading. We studied the effect ...

Subsurface modeling from seismic and borehole data is important for reservoir prediction, geophysical exploration, and production. A reasonable model should honor borehole rock properties and conform to seismic structural and stratigraphic features. Such a subsurface model can be difficult to build in cases complicated by faults and unconformities. Automatic and semiautomatic methods have been ...

In this paper, we demonstrate three-dimensional estimation of target positions with borehole radar in single borehole. We developed array type borehole radar having four dipole antennas with optical modulators. Experiment at a model site was done using the developed radar system. In the site, one borehole, in which there is no fluid, and one cave exist. Receiving dipole antennas and a transmitt...

In a Distributed Thermal Response Test (DTRT) the ground thermal conductivity and borehole thermal resistance are determined at many instances along the borehole. Here, such a test is carried out at a 260 m deep water filled energy well, equipped with a U-pipe borehole heat exchanger, containing an aqueous solution of ethanol as working fluid. Distributed temperature measurements are carried ou...

Directional drilling systems generate complex curved boreholes in the earth’s crust for the exploration and harvesting of oil, gas and geothermal energy. In practice, boreholes drilled with such systems often show instability-induced borehole spiraling, which negatively affects the borehole quality and increases drag losses while drilling. This paper presents a dynamic state-feedback controller...