Analysis of in Situ Stress Measurement by Hydrofracturing, and the Use of the Borehole Televiewer at Altnabreac

摘要

In situ stress measurement by hydrofracturing has been attempted in one deep borehole at Altnabreac in the Strath Halladale Granite. Although the results obtained were inconclusive, the hydrofracturing technique has been shown to be relatively simple to use in rocks of low permeability, and in addition the interpretation of the results is straightforward. The calculated in situ stresses exhibit a high horizontal stress ratio with the vertical stress being the intermediate stress. The borehole televiewer has been used to produce an acoustic picture of the borehole wall and is shown to be a valuable geophysical logging method for fracture analysis. The limitations of this technique are explained, and the results from the televiewer are compared with those derived from other methods of fracture analysis. (Atomindex citation 16:017575)