The blocks to be put up for auction on July 28 include three in the coastal basin of Kongo Central province, nine in the Cuvette Centrale, 11 near Lake Tanganyika and four near Lake Albert. The three gas blocks are on Lake Kivu.
Environmental groups and activists have expressed alarm at the plans, as many of the concessions overlap national parks. Congo has in the past defended its right to drill for oil in national parks.
The Cuvette Centrale in particular sits on peatlands that scientists say could release massive quantities of carbon dioxide into the atmosphere if disturbed.
Congo had initially planned to auction 16 oil blocks, nine of which overlapped with protected areas. The ministry said in its statement on Monday that it had decided to auction 30 now to maximise opportunities for the country.
Congo, a leading miner of copper, cobalt, gold and diamonds, has long aimed to boost its oil sector and is believed to have sizeable reserves. Output has remained flat for years at about 25,000 barrels per day because of underinvestment.