dear O&G experts,

does someone can tell me what is the meaning of cementing offline and online?
or if you have some reference for me regarding that?
im not so familiar with cementing stuff since i work only in wellhead stuff.
but some wellhead installation sequence was related to these cementing offline/online.

or this terms belong to some common terms in many many O&G reference books, i dont know exactly.
really appreciate your sharing.

thank you in advance

yudhi