Multicomponent seismic and borehole experiment to establish and identify the cause of anisotropy in the 2nd white specks at Garrington, Alberta

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:80201

Goodway, W N; Mayo, L F ^[1]

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1. PanCanadian Petroleum, Calgary, Alberta (Canada)

An orthogonal 2D multicomponent grid using compressional/shear airguns was acquired along with two P-Sv converted wave offset VSP`s and a zero offset shear VSP. The objective was to establish fracture orientation (assumed from caving zones in producing wells) within the 2nd White Speckled Shale of the Upper Cretaceous Colorado Group. Measurements indicate a periodic thin layering (PTL) anisotropy or transverse isotropy (TI), as opposed to fracture induced azimuthal or extensive-dilatancy anisotropy (EDA). TI or PTL anisotropy can give similar observations of S{sub 1}/S{sub 2} ray splitting, to fracture induced EDA, from propagation in off-principal axes (25{degree}--40{degree}) through clastic cyclothems, that are considerably less than a seismic wavelength Conclusions on anisotropy were made from stacking velocity differences between in-line Sv and cross-line Sh, despite consistent T{sub 0} times and interpretation of shear stacks with borehole measurements for evidence of shear wave splitting or rotation.

• OSTI ID: 80201
• Report Number(s): CONF-941015--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
ALBERTA
DATA ANALYSIS
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
ORIENTATION
PETROLEUM INDUSTRY
RESPONSE FUNCTIONS
SEISMIC SURVEYS
SEISMIC WAVES
WAVE PROPAGATION