You need a drill ship or mobile drilling barge to drill oil wells in the ocean.

how do i drill the other deposits the only one i know how to is with the custom rig

Some of the oil wells have a marker already before running this add-on.
When this add-on is run, it will add an additional marker over the top of the existing ones.
The first line reads okay with the deposit label, but the second line with the amount of oil remaining in the deposit is completely covered by the stock game's label making it unreadable.
The 3rd line with the depth is also fine.

I worked around this by tweaking the add-on code and putting an extra newline in the label string so it would display around the existing text.

You can use ?oil_remove to remove all markers and ?oil_info to show them again, as often as you like. Didn't test it with the default icons you get after purchasing oil data if that's what you mean, could be a quick fix.

urrrm, cant read how many litres is in a deposit as it clashes with other text on the oil wells??