Passive seismic imaging in the presence of white noise sources

Abstract The lateral well position uncertainty of magnetic/gyro MWD measurements can often exceed the requirements regarding anti-collision, for optimal placement of infill wells between existing producers, or for hitting targets with limited geological extent. The positional uncertainty can be significantly reduced by implementing high-precision drill-bit localization using passive seismic data. Consequently, not only drilling risks can be reduced, but optimal reservoir drainage is ensured as well. By utilizing passive seismic recordings from the seafloor, we can "listen" to the noise generated by the BHA while drilling. Despite various noise sources in the vicinity (e.g. vessels and rigs), advanced data processing and the combination of hundreds of seafloor receivers spread above the ongoing drilling, enable us to detect the drilling signal and locate the drill bit. Whereas the magnetic and gyro MWD tools have errors that accumulate with measured depth, each bit position derived from seismic (usually every 90 seconds) is completely independent. For horizontal sections, the error does not increase with measured depth, and hence can provide improved lateral accuracy. No additional BHA tool is required and the measurements are neither dependent on the magnetic nor gravitational field. Moreover, the passive seismic measurements can be used to obtain an improved lateral well position estimate. This is done by optimizing the azimuth information of the well trajectory in the minimum curvature method. A lateral uncertainty measure can be derived from the residuals between the passive measurements and the updated well path. Since 2018, we have used the continuous stream of passive data from permanent seafloor sensors at the Grane field with its reservoir depth of around 1800 m TVDSS to follow all wells with this drill bit tracking scheme. Lateral deviations from the magnetic/gyro measurements of up to 20m have been observed. The lateral position uncertainty can be as low as a couple of meters under optimal conditions.

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Engineering Impact from Passive Seismic Imaging of Hydraulic Fractures

10.3997/2214-4609-pdb.5.h045 ◽

2002 ◽

Author(s):

S.C. Maxwell ◽

T.I. Urbancic ◽

R. Zinno

Keyword(s):

Seismic Imaging ◽

Hydraulic Fractures ◽

Passive Seismic

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Passive Seismic Imaging by Using Data to Data Migration

77th EAGE Conference and Exhibition 2015 ◽

10.3997/2214-4609.201413261 ◽

2015 ◽

Author(s):

L. Wang ◽

X. Chang

Keyword(s):

Seismic Imaging ◽

Data Migration ◽

Passive Seismic ◽

Using Data

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Solving Noise Pollution Issue Using Plenum Window with Perforated Thin Box

Crystals ◽

10.3390/cryst10070614 ◽

2020 ◽

Vol 10 (7) ◽

pp. 614

Author(s):

Hsiao Mun Lee ◽

Andi Haris ◽

Kian Meng Lim ◽

Jinlong Xie ◽

Heow Pueh Lee

Keyword(s):

White Noise ◽

Traffic Noise ◽

Noise Pollution ◽

Experimental Results ◽

Frequency Range ◽

Noise Mitigation ◽

Noise Sources ◽

Acoustic Performance ◽

Common Noise ◽

The Common

In the present study, a conventional plenum window was incorporated with perforated thin box in order to enhance its performance at frequency range which centralized at 1000 Hz as most of the common noise sources at city nowadays are centralizing around this frequency. The entire studies were conducted in a reverberation room. The effectiveness of jagged flap on mitigating diffracted sound was also studied. Three types of noises were examined in the current study—white noise, traffic noise and construction noises. The experimental results showed that the plenum window with perforated thin box could reduce 8.4 dBA, 8.7 dBA and 6.9 dBA of white, traffic and construction noises, respectively. The jagged flaps did not have significant effect on the plenum window’s noise mitigation performance. When frequencies were ranging from 800 Hz to 1250 Hz, when compared with the case of without perforated thin box, it was found that the perforated thin box had good acoustic performance where it was able to reduce additional 1.6 dBA, 1.6 dBA and 1.2 dBA of white, construction and traffic noises, respectively.

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