Noise model estimation in multimeasurement data

Patent metadata

Field	Value
Publication number	US-10317547-B2
Application number	US-201514882903-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 15, 2014
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

Various implementations described herein are directed to methods for processing seismic data, including estimating a spectral noise power of multi-measurement seismic data received from a multi-dimensional seismic sensor array having multiple seismic sensors. The methods may include receiving a shot record of multi-measurement seismic data in time-domain, partitioning the shot record into overlapping time-space windows, and computing a frequency-domain spectrum for each time-space window. The methods may include computing a signal presence probability for each time-space window using the frequency-domain spectrum and prior probabilities of signal presence and absence for each time-space window. The methods may include iteratively updating a collective spectral noise power by recursively estimating the spectral noise power of a current time-space window based on the frequency spectrum for the current time-space window, the signal presence probability computed for the current time-space window, and a previously estimated spectral noise power of a previous time-space window.

First claim

What is claimed is:

1. A method, implemented by a computing system, that improves a seismic imaging process that facilitates hydrocarbon exploration via estimating a spectral noise power of multi-measurement seismic data received from a multi-dimensional seismic sensor array having multiple seismic sensors, the method comprising:
via the computing system, receiving a shot record of the multi-measurement seismic data in time-domain;
via the computing system, partitioning the shot record into a plurality of overlapping time-space windows;
via the computing system, computing a frequency-domain spectrum for each time-space window;
via the computing system, computing a signal presence probability for each time-space window using the frequency-domain spectrum and prior probabilities of signal presence and absence for each time-space window;
via the computing system, iteratively updating a collective spectral noise power by recursively estimating the spectral noise power of a current time-space window based on the frequency-domain spectrum for the current time-space window, the signal presence probability computed for the current time-space window, and a previously estimated spectral noise power of a previous time-space window; and
via the computing system, based at least in part on the recursively estimating the spectral noise power, processing at least a portion of the multi-measurement seismic data as part of a seismic imaging process that facilitates hydrocarbon exploration.

2. The method of claim 1 , wherein the multi-measurement seismic data comprises stationary noise and non-stationary noise, and wherein estimating the spectral noise power comprises estimating the spectral noise power of the stationary noise and non-stationary noise in the multi-measurement seismic data.

3. The method of claim 1 , wherein the multi-dimensional seismic sensor array is coupled to a streamer that is towed by a marine vessel, and wherein the multiple seismic sensors are coupled to the streamer at intervals along the streamer.

4. The method of claim 1 , wherein the multiple seismic sensors comprise a hydrophone, a first accelerometer configured in an x-coordinate direction, a second accelerometer configured in a y-coordinate direction, and a third accelerometer configured in a z-coordinate direction.

5. The method of claim 1 , wherein the shot record of the multi-measurement seismic data includes a combination of up-going and down-going wavefield data along with pressure noise data reflected from geological formations.

6. The method of claim 1 , wherein partitioning the shot record into a plurality of overlapping time-space windows comprises partitioning the shot record into a plurality of columns, wherein each column comprises a columnar series of overlapping time-space windows, and wherein each column is offset from each other column by at least one time-space window.

7. The method of claim 1 , wherein computing the frequency-domain spectrum for each time-space window comprises transforming each time-space window into a frequency-domain window using a Fast Fourier Transform (FFT).

8. The method of claim 1 , wherein the prior probabilities of signal presence and absence for each time-space window refer to respective likelihood functions of the multi-measurement seismic data in case of signal presence and absence.

9. The method of claim 1 , further comprising deriving an initial spectral noise power that is estimated from a time-space window having the least signal-to-noise ratio (SNR) when compared to other time-space windows, wherein the initial spectral noise power is used for recursively estimating the spectral noise power of the current time-space window.

10. The method of claim 1 , further comprising estimating the spectral noise power of the previous time-space window based on the frequency-domain spectrum for the previous time-space window and the signal presence probability computed for the previous time-space window.

11. The method of claim 1 , wherein recursively estimating the spectral noise power comprises recursively estimating signal-to-noise ratio (SNR).

12. The method of claim 1 , wherein computing the signal presence probability is based on a Bayesian framework for each time-space window using the frequency-domain spectrum and prior probabilities of signal presence and absence for each time-space window.

13. A device that improves a seismic imaging process that facilitates hydrocarbon exploration via estimation of a spectral noise power of multi-measurement seismic data received from a multi-dimensional seismic sensor array having multiple seismic sensors, the device comprising:
a processor; and
memory having instructions stored thereon that, when executed by the processor, cause the processor to:
receive a shot record of the multi-measurement seismic data in time-domain;
partition the shot record into a plurality of overlapping time-space windows;
compute a frequency-domain spectrum for each time-space window;
compute a signal presence probability for each time-space window based on the frequency-domain spectrum computed for each time-space window and previous information computed for a previous time-space window;
estimate the spectral noise power of the current time-space window based on the frequency-domain spectrum for the current time-space window, the signal presence probability computed for the current time-space window, and a previously estimated spectral noise power computed for the previous time-space window; and
based at least in part on the estimate of the spectral power noise, process at least a portion of the multi-measurement seismic data as part of a seismic imaging process that facilitates hydrocarbon exploration.

14. The device of claim 13 , wherein the memory further comprises instructions that cause the processor to iteratively update the spectral noise power by recursively estimating the spectral noise power of one or more next time-space windows based on the frequency-domain spectrum for the one or more next time-space windows, the signal presence probability computed for the one or more next time-space windows, and the previously estimated spectral noise power of the previous time-space window.

15. The device of claim 13 , wherein the multi-measurement seismic data comprises stationary noise and non-stationary noise, and wherein estimating the spectral noise power comprises estimating the spectral noise power of the stationary noise and non-stationary noise in the multi-measurement seismic data.

16. The device of claim 13 , wherein computing the frequency-domain spectrum for each time-space window comprises transforming each time-space window into a frequency-domain window using a Fast Fourier Transform (FFT).

17. A non-transitory computer-readable medium having stored thereon a plurality of computer-executable instructions which, when executed by a computer, cause the computer to improve a seismic imaging process that facilitates hydrocarbon exploration via estimation of a spectral noise power of multi-measurement seismic data received from a multi-dimensional seismic sensor array having multiple seismic sensors, wherein the computer-executable instructions that cause the computer to estimate the spectral noise power comprises computer-executable instructions that cause the computer to:
receive a shot record of the multi-measurement seismic data in time-domain;
partition the shot record into a plurality of overlapping time-space windows;
compute a frequency-domain spectrum for a current time-space window;
compute a signal presence probability for the

Assignees

• Schlumberger Technology Corp

Inventors

• Kamil Amin Yousif Izzeldin
• Loganathan Pradeep

Classifications

• G01V1/366 Primary

  by correlation of seismic signals · CPC title

• G01V2210/1423

  Sea · CPC title

• G01V1/30 Primary

  Analysis (G01V1/50 takes precedence) · CPC title

• G01V1/3808

  Seismic data acquisition, e.g. survey design · CPC title

• G01V2210/144

  with functionally associated receivers, e.g. hydrophone and geophone pairs · CPC title