Hi everyone, I'm running a MP game on a server and want to add this mod to my server. I have backed up my save file. What I wonder is if I just add this mod and load the game, will oversea oil patches show up in not-yet-discovered area? I currently use the Space Exploration mod and wonder what a change can this mod bring to an existing game.

Space Exploration is a mod in which there are many planets. So the question may have two parts: 1) will oversea oil patches be generated on my preexisting planets (just only in undiscovered areas); 2) will oversea oil patches show up on undiscovered planets (whose answer I assume is yes).

I'm neither the author of this mod nor have I used Space Exploration. However, I'd guess that Cargoships would behave with SE just as with other mods: oil patches are generated in newly generated chunks, not in existing ones. But perhaps you could test locally to make sure it really works as expected? Just make a copy of your savegame and add Cargoships to that. (At least, that's what I'd do -- but I play with a locally installed copy of Factorio, not via Steam.)

first of all, yes, when adding the mod midgame oil patches will spawn on newly generated chuncks. I am not sure though if they will also spawn on other planets.