... underground structures, such as cavems or tunnels. Depending on the domain of application, the most commonly used stress determination methods involve stress relief techniques, hydraulic tests in boreholes, analysis of borehole breakouts and drilling induced fractures, or inversion of seismic focal mechanisms...

...7th International Symposium on ln-8ilu Rock SU'ess May 1D-12, 2016, Tampers, Finland Johansson & Raasakka (ads) ISBN 978-951-758-606-1 ISSN 0356-9403 HYDRAULIC TESTING IN BOREHOLES FOR A ROBUST AND COMPLETE IN SITU STRESS DETERMINATION Francois H. Cornet (francois.comet@unistra.fr) EOST Universite...

... of the borehole measurements of elastic modulus in the rocks through the pressuremeter and hydraulic fracturing data sharing. The idea of the developed method is to use two different and independent data sets: the first one is obtained from standard deformation studies in well while the second one describes...

... the pore fluid pressure in fractured I porous formations and creates additional stresses and displacements. This in tum lowers the critical pressure required to initiate the fracture and reduces the width of the newly formed fracture. Once a fracture has been initiated at the borehole wall, the fluid...

...7th lntamatlonal Symposium on ln.Situ Rock S1ras8 May 1G-12, 2016, Tampera, Finland JohanMOn & R.aasakka (ed J ISBN 978-951-758-1Kl6-1 ISSN 0356-9403 APPLICATION AND INTEGRATED EVALUATION OF THE COMPACT CONICAL-ENDED BOREHOLE OVERCORING TECHNIQUE IN A FRACTURED ROCK Toshinori Nayuki...

... Leite Caroline Vezina Amalie c. Ouellet Po/ytachniqua Montreal Canada ABSTRACT In situ stress measurements based on the recovery principle, commonly called overcoring techniques, consist in calculating stresses under strain gauge rosettes using recovered strains at borehole walls or ends. These stresses...

... Abstract The results of stress measuring in quasi-plastic salt rocks and brittle sandstones are presented in article. Stresses were monitored in interchamber pillars using Goodman's hydraulic borehole jack. Acoustic-emission (AE) intensity was recorded as borehole walls were loaded. From...

... been measured with hydraulic jacking tests done in several boreholes. These boreholes are aligned and distributed along the axis of the future lined tunnel, starting from the powerhouse site to a distance of 350 m upstream. The tests were conducted in an undisturbed rock mass at variable depths...

.... In practice, however, axial strains are observed to be influenced by drilling effects during overcoring so that they vary with position around the borehole circumference in a sinusoidal pattern. This paper presents the results of axial strains measured at six locations around the circumference of a pilot hole...

... Abstract Hydraulic fracturing technique is a measurement method of in-situ rock stress. This technique has the highest track record for techniques used in sub 1000 mater. This technique is comparatively simple and easy for in-situ stress measurement, because a pre-existing drilled borehole...

... of hydraulic fracturing in a small hole drilled additionally at the bottom of a borehole. The small hole is referred to as a baby hole. Such a way seems complicated but it should minimizes a lime for tool selling overall while avoiding the risk of trouble in boreholes such as the tool gelling stuck. Upon...

..., the measured variation in elastic modulus around the borehole allows orientation of the other two principal stresses to be inferred from the in situ pressure test prior to overcoring. When the ratio of these other two stresses is known or can be estimated with reasonable confidence, the magnitude of the two...

... in the EDZ and provides better evaluation of the long-term safety and integrity of the rock mass around engineered openings in the nuclear disposal facility. Raasakka experiment Onkalo Ray Coverage plane excavation damage zone tomography p-wave velocity Upstream Oil & Gas borehole sensor...

.... Together with geological and morphological information and borehole and drillcore data one establish the Best Estimate Stress Model (BESM). In the next step, called Stress Measurement Methods (SSM), newstress data from borehole methods and core-based methods are recorded and evaluated. Thereafter, data...

... with the magnitude of earthquakes. It has been demonstrated that we can measure the process of change of stress field with the gauges in the borehole and make time, location and magnitude prediction for earthquakes. It has been 50 years since the method was used for the study of the premonitory stress observation...

... qiao in-situ stress measurement application China CAI Reservoir Characterization Upstream Oil & Gas borehole strain value roadway situ stress measurement result Rock Stress and Earthquakes Xie (ed.) © 2010 Taylor & Francis Group, London, ISBN 978-0-415-60165-8 New development...

... Upstream Oil & Gas river topography borehole application rock mass location 1 Rock Stress and Earthquakes Xie (ed.) © 2010 Taylor & Francis Group, London, ISBN 978-0-415-60165-8 Application of a global interpretation model for assessment of the stress field for engineering purposes L.N...

... ABSTRACT: At present, borehole strain observations are generally in the horizontal longitudinal components of the strain. These observations take stress concentration model of an infinite flat plate with hole as their theoretical basis and are used for measuring stress distribution and stress...

... ABSTRACT: Deep borehole observation can eliminate effectively various earth's surface interferences, providing considerable advantage over other geophysical measurements made at the ground, and improve greatly our capability to detect very small deformations and vibrations in the surrounding...

... and logging, geophysical investigations, in-situ stress measurements, laboratory testing and numerical modeling to design the under- ground storage facility in unlined mined caverns. Two NQ-size boreholes of 66 and 75 m depth were utilised for in-situ stress and permeability testing by fluid injection...