What was the minimum area in square kilometers that produced 3,200,000 (12th) bbl/day?
CREATE TABLE "table1_166346_1" (
  "country" text,
  "region" text,
  "joined_opec" real,
  "population_july_2012" real,
  "area_km" real,
  "production_bbl_day" text
);
SELECT MIN("area_km") FROM "table1_166346_1" WHERE "production_bbl_day"='3,200,000 (12th)';