Perhaps because of declining yields inland, the People's Republic of China has moved to its storm-ridden coast to develop additional petroleum reserves. During 1979 and 1980, 44 foreign oil-exploration companies engaged in what has been termed the world's record “seismic shoot” over 411,000 km2 extending from the Yellow Sea through the South China Sea, and including Beibu Wan (Gulf of Tonkin), the bay lying east of Hanoi and west of Hainan Island. These offshore oil reserves are estimated to be 40–100 billion barrels.
The seas off the mainland are relatively shallow (most drilling has been done in less than 100 m) but they are stormy. According to a recent description, “Typhoons can … occur in the area at almost any time of the year, and the strong winds (160 km h−1 or more) which they generate frequently wreak havoc in the Philippines, Vietnam, China, and occasionally, Hong Kong. Typhoon Vera, which hit southern China in late July, did immense damage and claimed dozens of lives. The main implications for oil operation naturally relate to rig design and safety measures but onshore facilities will also have to be designed accordingly” (New Scientist, Sept. 8, 1983).