The low-frequency tube wave speed is given explicitly for a variety of borehole nvironments. The presence of a logging tool, the effects of casing, and bore eccentricity are considered. The results are all relatively simple and indicate that the speed ecreases in the presence of a tool or borehole ccentricity. The speed increases in the presence of casing as long as the casing shear modulus exc...

Well-log measurements and seismic measurements should be compared at the same scale. The conversion of highly detailed borehole data into less detailed seismic data has to be done in a specific way considering conclusions from scaling analysis. One has to be careful with the differentiation to convert borehole acoustic impedance into reflectivity. In addition coarsening has to occur in such a w...

Thermal response test (TRT) is an established method to determine design parameters for borehole heat exchanger (BHE) systems; borehole thermal resistance and effective ground thermal conductivity. Most commonly, these tests are performed with heat injection, using the same assumed power level as the planned BHE system. For a thorough description of TRT and current activities around the world, ...

A fully polarimetric borehole radar system with four combinations of dipole and cylindrical slot antennas, as shown in Fig. 1, was developed to acquire fully polarimetric data sets in drilled boreholes [1]. The system in conjunction with a methodology of radar polarimetry analysis, proposed in previous (a) Measurement configuration (b) Antenna arrangements for polarimetric data collection Fig. ...

Method: In this paper, the shallow formation around the borehole is divided into plastic zone and elastic zone considering it under nonuniform in-situ stress. The collapse pressure formula of shallow formation is derived by taking the shrinkage rate of the borehole as the instability criterion. The fracturing pressure calculation model of shallow sediment under non-uniform in-situ stress is der...

Original scientific paper Traditional dc electrical exploration method will face great challenge when detecting deep, complex geologic target. With the purpose, forward modelling and inverse modelling method of borehole resistivity has been developed. According to the characters of geology, the geological model has been set up. The numerical simulation shows that borehole resistivity method is ...

The Forties Sandstone Member is an important deep-water reservoir in the Central North Sea. role of depositional characteristics, grain-coating clays, and diagenesis controlling quality sandstones poorly understood. main aim study to understand pore-filling evolution turbidite-channel sandstones. employed a multi-disciplinary technique involving thin section petrography scanning electron micros...

In this paper, we will introduce a cocentered orthogonal loop and dipole antenna (COLD) to a borehole radar system. With the cocentered orthogonal loop and dipole antenna, we could obtain additional information on polarization state of arrival waves in the borehole radar using * optical modulators. We set the proposed antenna in a borehole actually, and made electromagnetic waves with known pol...

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Overview of hydrogeologic tracer experiments and concepts. . . . . . . . . . . . . . . . . . . . . . . . . . 1 Expedition 327 tracer experiments. . . . . . . . . . 3 Tracer monitoring . . . . . . . . . . . . . . . . . . . . . . . 7 Summary of Expedition 327 tracer injection operations. . . . . . . . . . . . . . . . . . . . . . . . . ...

New-generation electromagnetic (EM) and sonic logging tools are capable of measuring multi-frequency multi-component data at multiple depths of investigation. This allows us to image the formation around the borehole by using an inversion method. A method is developed for directly obtaining porosity and fluid saturation distributions by simultaneously inverting borehole EM and sonic measurement...