Okay, the story doesn't add up, and you should be suspicious about this, particularly if he asks you for money to help him with this.
There are various red flags, firstly, being self-employed but being expected to pay taxes to the company. Secondly, being given a cheque for an international company instead of a direct transfer of payment to the bank; thirdly, randomly being held in an Embassy due to missing documents; fourthly, being taken back to an oil rig instead of sent back to his own country.
None of it makes sense, and it frankly has the pattern of a well known scam. I note my colleague asked you if you have ever met this person in the flesh and you said you had. If you had, then the scam is even bigger than if you haven't, as that takes some front to do that in person.
But even if you have met him, the red flags are enough for you to be suspicious. If you haven't handed over any money so far, then at least there is no financial damage.
I'm sorry to have to inform you of this, but the explanations he appears to be giving you just aren't realistic.