Few in the Australian oil patch were familiar with the term 'borehole breakout' when David Lowry alerted PESA Journal readers to this phenomenon (1990, v.17, p. 43-44). Ten years later, few are unfamiliar, with breakouts having been reported in every Australian basin subject to significant drilling activity. This change witnesses the dramatically increased awareness of borehole geomechanics in ...

Theoretical models for the thermal response of vertical geothermal boreholes often assume that the characteristic time of variation of the heat injection rate is much larger than the characteristic diffusion time across the borehole. In this case, heat transfer inside the borehole and in its immediate surroundings is quasi-steady in the first approximation, while unsteady effects enter only in ...

This paper presents a wellbore-stability study of the San Andreas Fault Observatory at Depth (SAFOD) research borehole located near Parkfield, California, USA. In the summer of 2005, the SAFOD borehole was drilled successfully through the active trace of the San Andreas Fault (SAF) in an area characterized by fault creep and frequent microearthquakes. In this study, we report how the analysis o...

The vadose zone beneath the USDOE’s Hanford Site in southeastern Washington State (Fig. 1) received approximately 1 trillion liters (450 billion gallons) of liquid waste, some contaminated with radioactive and hazardous contaminants. Today, Hanford is engaged in the world’s largest environmentalcleanup project, and a variety of conceptual and mathematical vadose zone models have been developed ...

Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could lead to a biased estimation of formation elastic properties measured from sonic logging data. To study the effect of stress concentration around a borehole on sonic logging, we first use an iterative approach, which combines a rock physics model a...

The great depth and relatively steep geothermal gradient (3⁄429oC=km) of the KTB deep crustal borehole, located in the Bavarian region of Germany, provides the basis for our study of diffusive argon loss in K-feldspar. The observed borehole temperature at 9 km is 3⁄4265oC which reaches well into the argon closure interval for K-feldspar (3⁄4125–350oC). Four microcline and two adularia samples d...

Access to clean water for drinking and sanitation is a human right. Today water scarcity is a large problem and inequality in access to safe water is a striking truth. In Mozambique, the US foreign aid agency Millennium Challenge Corporation introduced the Rural Water Point Installation Program to increase access to safe water and sanitation – a step towards reducing poverty. 600 water points –...

An investigative study was carried out to determine the bacteriological and physicochemical qualities of borehole and well water samples in Ijebu-Ode, Southwestern Nigeria. Ten water samples each of borehole and well water sources were collected within the geographical location. Physicochemical parameters were determined using standard methods. The total bacterial count was determined by pour p...

The correct design of a borehole heat exchanger (BHE) system implies the accurate knowledge of borehole and ground thermal properties, the correct evaluation of building heating or cooling demands and the correct procedure to assess the final overall BHE length related to BHE configuration shape. A careful design is required to make profitable payback plans and provide expected long time perfor...

There is growing interest in developing a three-dimensional (3-D) inversion and imaging technique from a single borehole. This problem can be solved by using tensor (multi-component) induction welllogging – TIWL. This method was originally introduced to resolve formation anisotropy. However, it was demonstrated in several publications that the TIWL instrument has sensitivity to 3-D conductivity...