According to Aramco, exploration and development will also commence in non - producing areas such the Red Sea and the Nafud basin, north of Riyadh.    From Wordnik.com.  [Energy profile of Saudi Arabia] Reference

A corridor of sandy terrain known as the ad-Dahna desert connects the large an-Nafud desert (c. 65,000 km2) in the north of Saudi Arabia to the Rub’al-Khali in the south.    From Wordnik.com.  [Arabian Desert and East Sahero-Arabian xeric shrublands] Reference