Kwang Jin Suh

US Patent:

20190369276, Dec 5, 2019

Filed:

Feb 23, 2017

Appl. No.:

16/478339

Inventors:

- Houston TX, US
Kwang Il SUH - Los Angeles CA, US

International Classification:

G01V 1/22
G01V 1/30
E21B 49/00

Abstract:

A backscattered signal can be received from a sensing fiber that extends into a wellbore. The backscattered signal can have been generated based on an optical signal launched into the sensing fiber. A first delayed signal, a second delayed signal, a first non-delayed signal, and a second non-delayed signal can be generated from the backscattered signal. A polarization control device can shift a polarization of the first delayed signal or the first non-delayed signal. A first demodulated signal can be determined based on the first delayed signal and the first non-delayed signal. A second demodulated signal can be determined based on the second delayed signal and the second non-delayed signal. Data about an environment of the wellbore can be determined by processing the first demodulated signal and the second demodulated signal to compensate for noise in the first demodulated signal or the second demodulated signal.

US Patent:

20180238732, Aug 23, 2018

Filed:

Oct 19, 2015

Appl. No.:

15/754139

Inventors:

- Houston TX, US
Kwang Suh - Los Angeles CA, US

International Classification:

G01H 9/00
E21B 47/12
G01V 1/22

Abstract:

A distributed acoustic sensing method that includes sending a sequence of optical pulses along an optical fiber, of at least two different widths, demodulating backscattered light from the optical fiber to obtain interferometric phase measurements as a function of position, combining the interferometric phase measurements to obtain a set of fade-resistant phase measurements, and storing or displaying the set of fade-resistant phase measurements. A distributed acoustic sensing system that includes a transmitter that sends a sequence of optical pulses along an optical fiber, of at least two different widths, a receiver that demodulates backscattered light from the optical fiber to obtain interferometric phase measurements as a function of position and combines interferometric phase measurements to obtain a set of fade-resistant phase measurements, and a storage or display device.