I just want to make sure I understand this correctly:

Ex: My investigator moves to a location with a portal. My investigator is "sucked in" to the left half of the portal location. I do an encounter according to the portal color, I make sure I get the corresponding text for the location, otherwise I use the generic "other" text . Turn continues as normal.

Next turn, I move my investigator to the right half of the portal location. again I make a "portal encounter". Turn continues as normal.

Next turn, I move out of a matching portal location gateway (it may be a different place as long as it's matching). I may now try to close the portal. If I succeed, turn continues and next turn I can continue exploring Arkham. If i fail, I can try to close the gate the next turn and so on..

Is this sequence correct?

Thanks

Pretty much, yep. :-)

Phase 2 (movement): you move onto a location with a gate. You deal with any monsters on that spot. You are not immediately sucked in this phase.

Phase 3 (Arkham Encounters): since you are on an open gate, you are sucked in.

Phase 4 (OW encounters): you have an OW encounter

Note that you do not enter gates during the movement phase.