Wohlers studied singing at the Hochschule für Musik und Theater Hamburg.
In May 1969 he sang Telemaco in a new production of the opera Il ritorno d'Ulisse in patria by Claudio Monteverdi.
There he mainly sang lyrical tenor roles, especially in the operas of Wolfgang Amadeus Mozart: Belmonte in Die Entführung aus dem Serail, Ferrando in Così fan tutte, Don Ottavio in Don Giovanni and Tamino in The magic flute.
Regular guest performances led him to the Hamburgische Staatsoper (among others 1984 in L'Ormindo by Francesco Cavalli), to the Bavarian State Opera and to the Vienna State Opera (1973-1980, as Tamino, Belmonte, Ferrando, Don Ottavo, Ernesto in Don Pasquale).
Other important roles of Wohlers were: Fenton in The Merry Wives of Windsor, Lenski in Eugene Onegin, Count Almaviva in The Barber of Seville and Nemorino in L'elisir d'amore.