14.3.2 Optical Path Inventory Representation

The optical path in Figure 14.3.1-1 is composed of the following components, which are referred to as the Inventory of components in the optical path.

• 5 fiber segments, one from each of these locations:

• the instrument box to the first connector (at the wellhead)
• the first connector to the turnaround at the bottom of the well
• the turnaround to the second connector
• the second connector to the splice

• the splice back to the terminator at the instrument box

• 2 connectors:

• 1 splice
• 1 turnaround

• 1 terminator of type ‘looped back to instrument box’ to represent that the optical path ends back into the instrument box in a dual-ended configuration. (The alternative type of terminator is ‘termination at cable’, where the optical path is single ended).

It is necessary to declare only those components and segments that are of relevance to the particular application or well design. If there is no interest in keeping track of splices and connectors, you can easily declare this optical path to consist of 1 fiber segment that happens to be the entire length of the optical path. Of course, doing so means that there is no mapping of possible anomalies to connections, etc., and no way to record different physical properties of each fiber segment.

In addition, OTDR (optical time domain reflectometry) tests can be reported for the optical path.