The Saudi Arabian government has announced investments worth US$20bn over the next years to maintain and possibly increase its spare oil production capacity. So far, the country is the only oil producer with significant spare crude oil production capacity to supply the market when requirement, bringing the maximum sustainable capacity up to 12 mb/d.
The government wants to keep it at least to this current levels and is mulling over a possible increase up to 13 mb/d. The additional 1 mb/d would cost US$20bn in capital expenditures while keeping the additional facilities online would cost about US$2bn/year in operational expenditures.
In October 2018, Saudi Arabia produces around 10.7 mb/d (expected increase in November 2018). Resuming crude oil production from the Neutral Zone between Saudi Arabia and Kuwait could add up to 500,000 bbl of oil output capacity to the two countries.