According to the book The Bridge: The Life and Rise of Barack Obama, there is mention that President Obama's father, Barack H. Obama, Sr. worked for BP back in the 1960s.
Obama senior's political mentor, Tom Mboya, made sure that he had decent jobs-as an economist for BP/Shell and then for both the ministry of Economic planning and development and the Ministry of Tourism."
President Obama's stepfather Lolo Soetoro also worked for an oil company, but the company is allegedly an American oil company. That would seemingly eliminate BP from being Soetoro's employer.
Soetoro worked for the Indonesian government and later a U.S. oil company before he and Obama's mother divorced in the late 1970s.
For any teenagers reading this site, yes, America used to have its own oil companies way back when before it became trendy and lucrative to be a multinational corporation.
Source: Chicago Sun Times; GodLikeProductions