I don't want to go into your personal life so I will just answer your questions:

1.Does he have a good chance of getting work there or should he have applied from his country and then come over?
If just getting work then he will have a good chance but if the question is a work with a salary he is expecting if he were hired from out of the Country, then I doubt it.
Most employers would think he is desperate for a job and may offer less than what he is expecting.

2. Will he be able to get a visa for me via his company?
If he gets his work visa and meets the requirements for family visa, yes he will be able to get visa for you.
As for the requirements for family visa, just do a search as that question has been asked here so many times.

3.Do most oil and gas companies provide a furnished place with others living in a compound?
It depends on the position in the company although most gas companies provide a furnished place to westerners and people in management position or high value skills.

4.what else do they offer?
I am not privy to other packages in Oil and Gas companies.

Hope this helps.