ILR expiry

[nasir]

hi,
I have ILR cause of marrige of my UK citizen wife (our marrieg still on), I lived in UK for 1 month and unfortunatly i did not get job in UK. i got an overseas job and would stay outside of UK. my question is :-
1) any expiry for my existing ILR if i stay outside of UK?
2) what period (days/months/year) ILR will considered expired?
3) can i return back to UK by using ILR

thanks

[Lucapooka]

2 Years.