Question : Advice getting a job opportunity in the Oil & Gas Sector

It is difficult to know why you are not succeeding. Is it your CV or your cover letter or the fact you may not have enough experience for an international company to want to expend the necessary effort /cost of sponsorship. Perhaps you can find out what companies need to do for sponsorship - contact the various embassies and find out what are the steps required. It might be that you need to get some work experience under your belt to make you an interesting candidate. I would try to contact individuals at the companies you are interested in and  find out whether you are an interesting candidate for them and what would you need to do to get a job in the company. I hope this helps.