HOW TO FIND SESSION ID OF A CONCURRENT REQUEST

You can use the following query to find Session Id of a Concurrent Request:

 SELECT ses.sid AS session_id, ses.serial#, fcr.request_id
  FROM v$session ses, v$process pro, fnd_concurrent_requests fcr
 WHERE     ses.paddr = pro.addr
       AND pro.spid = fcr.oracle_process_id
       AND fcr.request_id = :concurrentRequestId;

:concurrentRequestId is painted red area in the image below.