Analysis of coAnalysis of co--located located pressure and particle velocity pressure and particle velocity
measurements measurements
Alejandro D. Alcudia and Alejandro D. Alcudia and Robert R. StewartRobert R. Stewart
November 29November 29thth, 2007, 2007
OutlineOutline
ApplicationsApplications
ModellingModelling of sourceof source--generated airwavegenerated airwave
Microphones at Pikes Peak oil fieldMicrophones at Pikes Peak oil field
Vibration monitoring at Vibration monitoring at NantonNanton, Alberta, Alberta
ConclusionsConclusions
Lawton, D., 2004
Sound pressure level (dB)Sound pressure level (dB)
10102020
0000
3030404050506060707080809090
100100110110120120130130140140
Threshold of human hearing
Threshold of pain
⎟⎠⎞
⎜⎝⎛⋅=
20uPaΔPlog20dB 10
ΔPatm1Ptotal =−
Acoustic source Acoustic source modellingmodelling
Sallas et al. 1989; Norton and Karczub, 2003
Piston
Circular pistonvibrating in an infinite baffle
of radius r
Vibrator’s baseplatebehaves as a
big loudspeaker
Pistonaxis
Sound pressure simulationSound pressure simulation
Experiment at Pikes Peak oil fieldExperiment at Pikes Peak oil field
Dey et al., 2000; Hoffe et al., 2000
Pikes Peak 3Pikes Peak 3--C 2C 2--D field layoutD field layout
Hoffe et al., 2000
Shot gather Shot gather –– Microphone Microphone vsvs VerticalVertical
Linear sweep 8-25 HzNon-linear sweep 25 –150 Hz16 s length4 s listening
Microphone 100 m offset
Correlated microphone 100 m offset
Correlated microphone 460 m offset
Vertical geophone460 m offset
Horizontal geophone 460 m offset
Vibration monitoring at Vibration monitoring at NantonNanton, Alberta, Alberta
Protecting water springsDynamite and vibroseis sourcesPeak particle velocity (PPV) and peak over-pressure (PSPL)
StandStand--off distance (m)off distance (m)
100 m90 m64 mWater well 50 m90 m64 mArea of public congregation50 m90 m64 mResidence50 m90 m64 mStructure with concrete base15 m45 m32 mPipeline15 m45 m32 mOil or gas well100 m90 m64 mDam
Vibroseis2 kg < dynamite < 4kgdynamite < 2 kg
Stand-off distanceFacility
Canada Oil and Gas Geophysical Operations Regulations (SOR/96-117)
Dynamite 5m offset
PPV = 113 mm/s
PPV = 145 mm/s
PPV = 40.1 mm/s
Vibroseis 5m offset
PPV = 12.7 mm/s
PPV = 10 mm/s
PPV = 18.8 mm/s
0
1
1
1
1
0
0
0
0.5
0.5
0.5
0.5
ConclusionsConclusionsAirblast frequencies are affected by the sound radiation pattern
Airwave coupling is broadband. Stronger at low frequencies.
Lobes of radiated sound might impact the frequency content of the coupled airwave.
Measure three components for true PPV
AcknowledgementsAcknowledgementsAOSTRA and Husky Energy Inc.
Nanna Eliuk of Compton Petroleum Corporation
Rick Espersen
Greg Nieuwenhuis of WorleyParsons Komex
CREWES sponsors and staff for their support
Dr. Gary Margrave for Gabor transform code and Dr. Robert Ferguson for discussions.
