The Brazilian striker is set to put pen to paper on a deal that will see him feature in the Qatar Stars League next season
The Brazilian had been linked with a host of clubs, including Internacional, following Villarreal's relegation from La Liga last season.
"Nilmar [is set] to complete the negotiations attached to the club Al Rayyan," read a statement on the Qatar outfit's official website on Thursday.
Subject to finalising the deal, Nilmar will link up with fellow Brazilian Rodrigo Tabata next term.
Nilmar, 27, scored 26 goals in 85 Primera Division appearances during his time at Villarreal.