This maybe offset by new discoveries, although no large oilfields have been discovered since 1980.
The nation's largest oilfields begin 62 miles northwest of Harbin.
Staff General Ali Ghaidan Majeed, the commander of Iraqi ground forces, called it a "dangerous development" and an apparent attempt to reach the area's large oilfields.
This heavily industrialised area, which had a greater population density than New York State, contained some of the largest oilfields in the world.
The spending has far outstripped the tens of billions of dollars earned annually from the largest oilfields in the world, which the Government owns.
The two largest oilfields in North America are on the North Slope.
That nation, already with a fourth of the world's known reserves, recently announced discoveries of large oilfields.
Independent estimates place the gross oil-in-place (OIP) volume at 13.7 billion barrels (P50) making it one of the largest oilfields discovered in recent years.
The new law eliminates a tax break for the nation's two largest oilfields, at Prudhoe Bay and Kuparuk, both on the North Slope.
The country has 11 explored oilfields with reportedly 28 Mt of oil resources; larger oilfields are also thought to exist.