The company that I applied for is also Oil/Gas company, same as Petrochemical. Their (the company) medical examination requisition letter has a written statement something like this: "Note: Person Having TB, HBV and HIV are not allowed to work in Qatar". That's why I was confused because my previous company had requested me to have a PROFILE TEST for HBV and I passed it and they give me a medical waiver letter, so that I can work with them.
But this new company is not doing like that. Maybe this company is not aware of that.