From my understanding they are all referring to the same covenant, with chapter 17 being the climax of it, or the full detail of it. God is promising to bless Abram/Abraham with land and offspring (note: very specific land and very specific offspring) Both of these blessings are mentioned in all three passages. And it is also important to note that Abraham has an end to hold up in this covenant as well. God will provide these things for him, and in turn, Abraham is to walk with God and be blameless.