Is it obligatory to make up prayers for more than two years if they were performed without intention?

Undoubtedly, a worshiper prays with intention (niyyah), for intention is the presence in the heart of the act of prayer. It is not a condition to utter it verbally; in fact, doing so is not legislated. Shaykh al-Islam Ibn Taymiyyah clarified that intention follows knowledge, so whoever knows what he intends to do must necessarily have the intention for it. Therefore, there is no need to repeat previous prayers.