نتایج جستجو برای: borehole
تعداد نتایج: 3770 فیلتر نتایج به سال:
Interpolated contour maps drawn for aluminum, copper and molybdenum in downstream monitoring boreholes of water dam in Miduk Copper Complex and the values of pH, redox potential (Eh) and distance from water dam indicate different trends of variation and behavior of these three elements in downward groundwater resources. As these maps exhibit, aluminum is dominant in the most alkaline (pH = 9-11...
We present a feasibility study for interpretation of gravity gradient surveys in a single borehole using both an analytic and inverse-based approach. We analytically solve for distance and direction angles to a point source using the components of the gravity gradient tensor from a set of observations in a single borehole. We then generalize this approach to include the response due to a prisma...
We present a borehole failure model which is based on fracture mechanics and layer buckling theories and compare its prediction with experimental data. The model assumes that the main mechanism of borehole collapse takes place in the form of layers buckling near the borehole surface. The model introduces a combination of fracture mechanics parameters with dimension of length that scale the size...
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 ...
Detailed information about the spatial distribution of subsurface properties is important in many fields. One method that can image the seismic velocity structure of the shallow subsurface is crosswell seismic tomography. By including rays traveling from the boreholes to the surface, the angular coverage of crosswell tomograms can be significantly improved. We investigated the effects of these ...
Before embarking on any mining operation, it is advantageous to locate the subsurface orebody in three-dimensions with a high resolution (~1m) ahead of actual mining, because this will increase productivity and efficiency. Borehole radar is such an emerging mapping tool in the mining industry, that can be used to image the subsurface orebody with high resolution. 3-D subsurface imaging using tw...
Borehole radar is an electromagnetic tool that can be applied to assist in the delineation of orebody geometry, ideally using routinely drilled cover and exploration boreholes. Successful trials of borehole radar for delineating reef horizons on South African gold and platinum mines have led to the development of a borehole radar system specifically designed for routine application in those eny...
We have employed a few-parameter estimation (FPE) technique to derive information on past surface temperature variations from present-day borehole temperatures. Synthetic experiments show that the FPE t•hnique can separate reasonably well information on century-long trends of surface temperature change from borehole temperatures within a .wide range of noise levels. The technique also allows a ...
We present a method of calculation to simulate the propagation of acoustic and elastic waves generated by a borehole source embedded in a layered medium. The method is formulated as a boundary element technique where the Green's functions are calculated by the discrete wavenumber method. The restrictive assumptions are that the borehole is cylindrical and that its axis runs normal to the layer ...
An impulse-based single-borehole radar prototype has been developed for well logging. The borehole radar is comprised of subsurface sonde and surface equipment. An armored 7-conductor well logging cable is used to connect subsurface sonde and surface equipment which is well compatible with the other well logging instruments. The performance experiments of the prototype have been conducted in a ...
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