Receiver function is defined as the spectral ratio of the radial component and the vertical component of the ground motion. It is used to characterize converted waves. We extend the use of the receiver function to downhole data using waves recorded in a borehole, excited by an earthquake of magnitude 4.0 near San Francisco, California, on 26 June 1994. The focal depth of the event was 6.6 km an...

knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. in this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells a and b...

The propagation of seismic waves in an open borehole is reviewed. The principal wave types are the refracted P and S waves and the two guided waves pseudo-Rayleigh and Stoneley. The dispersion properties of the gUided waves are analyzed. An efficient method of computing synthetic microseismograms is described. The relative effects of the borehole. fluid and formation properties on the propagati...

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 ...

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...