SP was into all kinds of stuff over its history. The pipelines shared the existing right of way, but was primarily for domestic distribution not any import/export that I am aware of. They also owned a trucking companies (such as PMT) and an interest in Greyhound, both of which allowed them to abandon unprofitable lines/services. I remember a SP brochure stating that they started some vineyards to use the salvaged poles and wire as they switched to microwave. The surplus microwave capacity was leased out, but SP didn't have the money (or interest?) to compete in the modern communications market so they sold SPRINT off.

SP did have quite the Navy. There was a fleet of passenger ferries that ran from Oakland to San Francisco (one preserved in San Diego), a fleet on the Great Salt Lake for building/maintaining the trestle and later the fill, plus others at various times for construction. They also ran car and passenger ferries in several places before bridges over major waterways were built. I don't recall ever hearing any marine service to haul petroleum in connection with the pipeline.