I know that an adoptive parents is considered as a real parent. But normally the adoptive parents raises the child from a very young age, in this case it is different. A Jewish father bring up his son till the age of 7, then the couple splits, and he leaves.the family.The boy's mother goes to live with another Jewish man, who raises the boy from the age of 8 on. There will be no relationship between the biological father and son from that time. The son sees the "second" father as the real one. When the child marries, is he halakhically allowed to indicate in the Ketubah the name of the adoptive father, despite the fact that biological father has raised him up to the age of 7?
There are several ways this can be worded:
X the son of Z who raised him
X the son of Y, who is known as [or who goes by] X the son of Z, (who raised him as his son).
That's what written into the legal text of the ketubah. It's at the couple's discretion what to read out-loud at the ceremony.
(There are some lectures from Rabbi JD Bleich on yutorah about this).