Estimation of in-situ stresses from ultrasonic measurements

Journal Article · Wed Oct 01 04:00:00 EDT 1986 · SPE (Society of Petroleum Engineers) Format. Eval.; (United States)

DOI:https://doi.org/10.2118/12850-PA· OSTI ID:5097093

Mao, N H; Sweeney, J J

The results of an effort to develop a technique for estimating in-situ stresses by measurement of stress-induced velocity anisotropy around a borehole are presented. Relevant parameters required to make the estimate were identified and measured in the laboratory on a 35.6-cm (14.0-in.) cube of Nugget sandstone with a 10.2-cm (4.0-in.)-diameter hole under biaxial loading. Two pairs each of radially and tangentially polarized transducers were placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times were measured by both a pulsed phase-locked loop (P/sup 2/L/sup 2/) technique and a cross correlation of digitized waveforms. The biaxial velocity data were used to back-calculate the applied stress. The standard deviation of the differences between the calculated and applied stresses is 0.62 MPa (90 psi) for a stress level up to 8.63 MPa (1,252 psi).

• Research Organization: Lawrence Livermore National Lab.
• OSTI ID: 5097093
• Journal Information: SPE (Society of Petroleum Engineers) Format. Eval.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Format. Eval.; (United States) Vol. 1:5; ISSN SFEVE
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ACOUSTIC MEASUREMENTS
ANISOTROPY
BENCH-SCALE EXPERIMENTS
BOREHOLES
CAVITIES
MEDIUM PRESSURE
NATURAL GAS WELLS
OIL WELLS
PHASE VELOCITY
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SOUND WAVES
STRESS ANALYSIS
STRESS INTENSITY FACTORS
TIME MEASUREMENT
TRANSDUCERS
ULTRASONIC WAVES
VELOCITY
WAVE FORMS
WELLS