BRITISH Petroleum or Royal DUTCH Shell
Nitpick1: British Petroleum does not have any stake in Venezuela. They do in the Caribbean islands though (Trinidad). They are also a major player in Gulf of Mexico and a major supplier into the USA, and a major employer in the USA. The name (which they don't use) is sort of irrelevant for a multinational. This "British" companies is listed on the New York Stock Exchange (as well as London), has a predominantly American shareholder investment, predominantly American workforce, and has most of its major assets in America along with it's biggest office (though not main office, that is still London). America stands to gain a lot by supporting "British" petroleum.
Nitpick2: Royal DUTCH Shell is Shell plc. They are a 100% British multinational listed on the London stock exchange. They haven't been Dutch for a few years now, they moved their headquarters to the UK, and they dropped all references to Royal Dutch (the former oil company) during the movie and with great irony now only reference the Shell side of the business (the irony being that Shell no longer have a shipping division which is what Shell originally was when it merged with Royal Dutch Petroleum). Shell stands to gain a shitload from this though. They were a player in the Venezuelan oil industry.
Nitpick3: What USA companies say is related to the situation of the day. Exxon, ConocoPhillips and Chevron were all major players in Venezuela but got bitten. They had no interest in going back *under the current government*. As the situation evolves so does the business strategy. IF (big if) the outcome of this invasion is a stable international Venezuela, you can bet both your kidneys with safety that all three companies will come racing back. Their shareholders will very much demand it.