What is the ruling on a man marrying a woman residing in Riyadh without documenting the contract and without a shaykh, in the presence of the bride's father and two of the groom's friends as witnesses, with a prior agreement to divorce her upon her final departure from the country after a year and a half, and what is the ruling of Sharia regarding the actions of the groom's friends?

If a marriage is limited to a specific duration, or conditioned upon divorce at a known time, then it is a temporary marriage (Nikah Mut'ah), which is invalid and unanimously forbidden. If such a marriage occurs, the spouses must be separated, and those who participated in it must repent to Allah. As for a valid marriage contract (Nikah Sahih), it must fulfill the legal pillars and conditions, such as offer and acceptance, the consent of both spouses, the presence of the guardian (wali) and two witnesses. It is valid even without official documentation, but documentation is important for preserving rights.