Currently, its ICAO designation is VV02
Bien Hoa Airport Bien Hoa, Dong Nai Province, Vietnam
elevation 79 feet.
Don't think there was an ICAO designation, for the base when USAF operated it.
Although it did have an operating location Identifier, when SAC operated U-2s out of there.
Bien Hoa AB's SAC designator was: OL-20
(believe it was later changed to DEN-20 ?)
Base was also known by code names; 'Lucky Dragon', 'Giant Dragon', and 'Trojan Horse'
http://www.airportsearch.info/airports/Asia/Vietnam/Dong-Nai/Bien-Hoa-Air-Base/VV02.php
John