help!!!

[andy john 2009]

hi i got myself a volvo and now got a prob with it, when u start the car up it fine but when the engine has warmed up and u stop for afew mins then pull away there is blue smoke coming out, also it is drinking oil, put in 1 litre of oil in 2days, we have got a volvo 850 2.5 10v none turbo
hope someone can help us, cant believe this has happen as only just got it
thanks