OPTICAL COUPLERS USED IN A DOWNHOLE SPLITTER ASSEMBLY

摘要

Techniques and apparatus are provided for downhole sensing using optical couplers in a downhole splitter assembly to split interrogating light signals into multiple optical sensing branches. Each optical branch may then be coupled to an optical sensor (e.g., a pass-through or an optical single-ended transducer (OSET)) or to another optical coupler for additional branching. The sensors may be pressure/temperature (P/T) type transducers. Some systems may exclusively use OSETs as the optical sensors. In this manner, if one of the OSETs is damaged, it does not affect light traveling to any of the other sensors, and sensing information from remaining sensors is still returned.

主权项

1. A system, comprising:
at least first and second optical sensing branches located downhole in or near a wellbore, each of the branches having at least one single-ended optical sensor to measure one or more downhole parameters that does not pass the interrogating optical signals through; a first optical waveguide for guiding interrogating light signals downhole to interrogate optical sensors in each of the first and second optical sensing branches; and a first optical coupler to split the interrogating light signals between the first and second optical sensing branches and to guide light signals reflected from the first and second optical sensing branches back to the first optical waveguide.