Nether portal spawned me around 1500 block away from where the portal was supposed to

I had walked into a portal my friend had walked through a. Implement times in his base but when I tured around after walking into the neither it was no where to been seen. He tried to come get me but we needed up being 1500 blocks apart when we walked through the same portal. Took me an hour to mine there by hand because my pick axes broke.