. as of december 31 , 2013 , we own or have rights to participate in developed and undeveloped leases totaling approximately 159000 gross ( 32000 net ) acres . the underlying developed leases are held for the duration of the project , with royalties payable to the province of alberta . synthetic crude oil sales volumes for 2013 were 48 mbbld and net-of-royalty production was 42 mbbld . in december 2013 , a jackpine mine expansion project received conditional approval from the canadian government