Last year, China became the world’s second-largest importer of oil (take a wild guess who’s No. 1), struggling to keep up with the energy demands of an economy expanding at a rate of 9.9 percent annually. Having recently concluded, like other oil-thirsty countries, that the volatile Middle East might not be a stable, long-term source of black gold, China has begun jostling with other global energy consumers — notably the U.S., Japan, and Europe — to find oil in more out-of-the-way locations. Recent months have seen Chinese President Hu Jintao visit the African nations of Gabon and Algeria, not exactly high-profile diplomatic allies, but lucrative sources for oil contracts. China’s ballooning energy demands are helping to fuel an oil boom in West Africa.