Stress measurements in anisotropic rock by hydraulic fracturing

Conference · Sun Dec 31 23:00:00 EST 1972 · Proc. US Nat. Comm. for Rock Mech. Appl. of Rock Mech. Symp.; (United States)

OSTI ID:6427501

Haimson, B C; Avasthi, J M

Many practical applications of rock mechanics require knowledge of the in-situ state of stress. Conventional stress measuring methods, such as borehole deformation gage and door stopper techniques, are severely limited in depth, rock quality, and stress level. Hydraulic fracturing has the potential of overcoming most of these limitations, and so far laboratory experiment and field measurements have demonstrated the soundness of the technique in intact quasi-isotropic rock. Recently an experimental program was undertaken to study the effectiveness of hydraulic fracturing in extremely anisotropic rock. Thinly foliated Martinsburg slate was hydrofractured at 4 different cleavage inclinations, under a set of 3 unequal simulated principal in-situ stresses. The results showed a predictable relationship between in-situ stresses and hydraulic fracturing pressures dependent on filiation inclination. Under normal in-situ stress conditions, and by hydrofracturing through a thin lining of Plaster of Paris, all the induced fractures were vertical and perpendicular to the direction of the smaller horizontal principal stress, just as in the isotropic case.

• Research Organization: Wisconsin Univ, Madison
• OSTI ID: 6427501
• Report Number(s): CONF-7309108-
• Journal Information: Proc. US Nat. Comm. for Rock Mech. Appl. of Rock Mech. Symp.; (United States), Journal Name: Proc. US Nat. Comm. for Rock Mech. Appl. of Rock Mech. Symp.; (United States)
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ANISOTROPY
CLEAVAGE
COMMINUTION
CRACK PROPAGATION
CRYSTAL STRUCTURE
FRACTURING
GEOLOGIC STRUCTURES
HYDRAULIC FRACTURING
INCLINATION
MATERIALS TESTING
MEASURING METHODS
MECHANICS
MICROSTRUCTURE
ROCK MECHANICS
ROCKS
STRESS ANALYSIS
STRESSES
TESTING