From the Wikipedia page 
Ruweng State is one of the 28 states of South Sudan. It is located in the Greater Upper Nile region and it borders Western Nile to the east, Western Bieh to the southeast, Northern Liech to the south, Twic to the southwest, Abyei to the west, and Sudan to the north.
On 2 October 2015, President Salva Kiir issued a decree establishing 28 states in place of the 10 constitutionally established states. The decree established the new states largely along ethnic lines. A number of opposition parties and civil society groups challenged the constitutionality of the decree. Kiir later resolved to take it to parliament for approval as a constitutional amendment. In November the South Sudanese parliament empowered President Kiir to create new states.
The state consists of the 2 counties of Pariang and Abiemnhom.