US 11,946,365 B2
Multi-fiber sensing topology for subsea wells
Glenn Andrew Wilson, Houston, TX (US); Sigurd Moe, Kongsberg (NO); Andreas Ellmauthaler, Houston, TX (US); and James Dupree, Humble, TX (US)
Assigned to Halliburton Energy Services, Inc., Houston, TX (US)
Filed by Halliburton Energy Services, Inc., Houston, TX (US)
Filed on Aug. 13, 2021, as Appl. No. 17/402,094.
Prior Publication US 2023/0052444 A1, Feb. 16, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. E21B 47/135 (2012.01); H04J 14/02 (2006.01)
CPC E21B 47/135 (2020.05) [H04J 14/02 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for fiber optic sensing (FOS) comprising:
transmitting one or more light pulses from an interrogator that is optically connected to a proximal wavelength division multiplexer (WDM), wherein the proximal WDM is disposed in a WDM compartment that is separate and apart from the interrogator;
multiplexing the one or more light pulses from the interrogator with the proximal WDM into an upgoing transmission fiber and a down-going transmission fiber;
passing the one or more light pulses from the proximal WDM through a proximal circulator disposed between the proximal WDM and a distal WDM;
receiving the one or more light pulses with the distal WDM that is optically connected to the upgoing transmission fiber and the down-going transmission fiber;
multiplexing the one or more light pulses with the distal WDM;
sending the one or more light pulses form the distal WDM to at least one of one or more downhole sensing fibers; and
receiving backscatter light from at least one of the one or more downhole sensing fibers at the distal WDM.