The temperature response in the soil surrounding multiple boreholes is evaluated analytically and numerically. The assumption of constant heat flux along the borehole wall is examined by coupling the problem to the heat transfer problem inside the borehole and presenting a model with variable heat flux along the borehole length. In the analytical approach, a line source of heat with a finite le...

The in situ thermal conductivity of the subsurface has been measured with a novel thermal response test using heating cables inserted in a vertical ground heat exchanger. An electric current is applied along the cables to heat the borehole prior to measuring water temperature recovery at various depths inside the ground heat exchanger piping. The one-dimensional line-source equation, combined w...

Oil shale is a kind of potential alternative energy source for petroleum and has attracted the attention of energy researchers all over the world. Borehole hydraulic mining has more prominent advantages than both conventional open-pit mining and underground mining. It is very important to attempt to use the borehole hydraulic mining method to exploit underground oil shale. The nozzle is the key...

[1] The accurate characterization of the location, hydraulic properties, and connectivity of major fracture zones is essential to model flow and solute transport in fractured media. Cross-borehole flowmeter tests, which consist of measuring changes in vertical borehole flows when pumping a neighboring borehole, were shown to be an efficient technique to provide information on the properties of ...

Flexural waves generated by a dipole source have been studied theoretically and used to estimate the shear parameters of a formation. The basic principles and main properties of flexural waves propagating in a borehole are reviewed in this paper. A mono/dipole transducer made of a PZT piezoelectric tube is used for laboratory experiments in borehole models. The radiation pattern of the dipole s...

This paper presents an inversion algorithm for obtaining azimuthal angle and borehole flexural wave dispersion in an anisotropic formation. The technique constructs an objective function that can be minimized using standard non-linear inversion methods, which is sensitive to both dispersion and rotation. The method is tested on both synthetic and real borehole data and gives good agreement with...

An important issue in the design of systems using borehole heat exchangers is to find costeffective methods to construct the borehole heat exchanger so that heat can be injected or extracted from the ground without excessive temperature differences between the heat carrier fluid and the surrounding ground. This paper presents an overview of experiences and current activities in this field.

A blended neighbor method for image-guided interpolation enables resampling of borehole data onto a uniform 3D sampling grid, without picking horizons and without flattening seismic images. Borehole measurements gridded in this way become new 3D images of subsurface properties. Property values conform to geologic layers and faults apparent in the seismic image that guided the

A scientific drilling expedition to the High Lake region of Nunavut, Canada, was recently completed with the goals of collecting samples and delineating gradients in salinity, gas composition, pH, pe, and microbial abundance in a 400 m thick permafrost zone and accessing the underlying pristine subpermafrost brine. With a triple-barrel wireline tool and the use of stringent quality assurance an...

A microbial community analysis using 16S rRNA gene sequencing was performed on borehole water and a granite rock core from Henderson Mine, a >1,000-meter-deep molybdenum mine near Empire, CO. Chemical analysis of borehole water at two separate depths (1,044 m and 1,004 m below the mine entrance) suggests that a sharp chemical gradient exists, likely from the mixing of two distinct subsurface fl...