Gilbert Brown learned the oil business at age 15 in the Petrolia oil fields. His time abroad began with a contract to drill oil wells in Egypt in 1913. Some of these wells are still in production today. Following this he went on three trips to the Middle East where he was involved in building a pipeline in Iran for four years, and then drilled for the Persian Oil Company for another four years. From there, he travelled to Venezuela for three years before returning to Canada and retiring from the foreign fields. After moving to Sarnia, he remained in the oil business but as a merchant and opened an Imperial Oil Service Station. A small rack in the corner of the waiting room sold Canadian Tire products such as batteries and other products. This would be the precursor to the first Canadian Tire store in Sarnia, which Gilbert Brown opened in 1938.

At some point in his early career, around 1910, Gilbert Brown was contracted by Imperial Oil to investigate the tar sands in Northern Alberta. The journey north must have been its own adventure and was certainly not done in the leisurely-style of his later trips to the Middle East. After a long ride to Edmonton from Ontario, he travelled by stagecoach for about 13 days up to Athabasca Landing along a muddy, rutted trail. He then embarked on a steamship and drifted along the Athabasca River until he reached Fort McMurray. All of the effort of reaching the tar sands proved futile. Gilbert Brown wrote to Imperial Oil to inform them that it would not be practical to extract the oil from the tar sands. The challenges continued as the group attempted to leave before the fall freeze-up. Due to unknown circumstances, they could not drift along the river back to Athabasca Landing and were forced to make the 150-mile trip on foot. No doubt Gilbert Brown would be happy to return home, although the trip appeared to have had a positive impact because what followed was a long career in the international oil fields.