Canon Law requires the men chosen to be bishops to have a doctorate. Can. 378 § 5 says that the candidate should “hold a doctorate or at least a licentiate in sacred Scripture, theology or canon law, from an institute of higher studies approved by the Apostolic See, or at least be well versed in these disciplines.”
Richard Chonak has an interesting post on the spread of doctorates in the College of Cardinals. He limits his survey to cardinal electors between the ages of 60 and 75 (the most papabile). Of the 67 cardinals surveyed, only three possess a doctorate in Sacred Scripture. That’s not surprising. The SSD is one of the most demanding of all doctorates. Doctors of Sacred Scripture must first earn a Licentiate of Sacred Scripture, and only the Pontifical Biblical Institute the Pontifical Biblical Commission grant them (in course and by examination respectively). Candidates typically live in the Holy Land for several years, becoming conversant in biblical archaeology, Ancient Hebrew and Koine Greek.
The Archbishop of Brisbane is a Doctor of Sacred Scripture, and it shows in his Lenten message. This is great viewing (or reading). The fourteen minutes it takes to watch this is, I think, a good investment of time.