I would say it is a good start. Some skills that you learn in the shipyard can be applied in O&G. Based on my experience just take that job first then continue to apply directly into O&G companies. Since you are a fresh grad usually companies won't expect much from your working experience.

If you apply for a job in big O&G companies like Shell etc, anyone with working experience of 5 and below is considered fresh graduate. Therefore your prior experience is not really the main thing their are looking for at hiring people. Since you are fresh, companies pay more attention to the type of person you are in terms of character and how you carry yourself. Even working 2 years outside you will be competing with people who are just fresh out of university. You will be surprised to find people with mechanical / electrical / electronic degrees doing Petroleum engineering's job in O&G.

Just be frank and honest about it. If you have a gf/wife/foreveralone. Working offshore does not need you to sell your soul by giving up all luxury of life to work. Very common people working offshore have their own families. If a company expects that you can't have a gf don't work for that company as it is a slave driver company.

To me the main reason they ask is see if there is a conflict of interest. Like your wife or family members work in Petronas and you work in Shell. Beside that probably just want to create some conversation and get to know you better.