Directional acoustic surveying instrument

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · SPE (Society of Petroleum Engineers) Drill. Eng.; (United States)

OSTI ID:5694322

Treherne, D M; Harper, P G; Su, D

A new type of acoustic detector capable of determining the direction of a noise source was developed. Under granite transmission at a depth of 600 m (1,970 ft) and ranges up to 200 m (655 ft), directional accuracies of 1 to 2/sup 0/ were achieved. Detectable sources included quasicontinuous (e.g., drill-bit) noise and pulses (3.g., explosive or sparker tool). The sensing element is a symmetric resonator whose flexural modes are readily excited by an external acoustic source. The physical principle is that the phase plane of a strong acoustic spectral component fixes the nodal directions of the resonant flexural vibrational mode, thus establishing the propagation direction in relation to the modal symmetry. The resonator is encapsulated in oil to damp the vibrations and to retain and communicate the acoustic signal. (The vibrational modal pattern is detected with strain gauges and processed to provide directionality). This paper presents (1) vibrational response theory; (2) construction details; and (3) analysis of field data leading to directionality.

• Research Organization: Heriot-Watt Univ. (US)
• OSTI ID: 5694322
• Journal Information: SPE (Society of Petroleum Engineers) Drill. Eng.; (United States), Vol. 4:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
WELL DRILLING
ACOUSTIC MONITORING
DATA ANALYSIS
DIRECTIONAL DRILLING
DRILL BITS
EQUIPMENT
FIELD TESTS
GRANITES
MECHANICAL VIBRATIONS
NOISE
WAVE PROPAGATION
DRILLING
DRILLING EQUIPMENT
IGNEOUS ROCKS
MONITORING
PLUTONIC ROCKS
ROCKS
TESTING
020200* - Petroleum- Reserves
Geology
& Exploration