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DSP: a new instrument for estimation of the in-situ stress state at depth

Conference · · Soc. Pet. Eng. AIME, Pap.; (United States)
OSTI ID:7082984
The deep stress probe (DSP) is a hydraulically operated tool which is a combination straddle-packer and impression packer which can determine the orientation (inclination) and azimuth of induced fractures. Results are discussed of 2 field tests recently conducted in the Granite Mt. Quarry near Marble Falls, Texas, to determine in situ tectonic stresses. The experiments were performed in a 4-3/4-in. diam hole, 1,150 ft deep in granite. The borehole was fractured at various horizons, using different fracturing fluids to determine the most suitable system for future tests in hard rock. Downhole pressure readings were taken and oriented impression packers were used to determine the azimuth of the induced fractures. Results of the DSP tests are compared with earlier results obtained by overcoring. The results suggest that lateral stresses at the depths tested are less than may be inferred from the surface tests.
Research Organization:
Minnesota Univ.
OSTI ID:
7082984
Conference Information:
Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE-4246
Country of Publication:
United States
Language:
English