Chinese state oil giant Sinopec is opening a major ultra-deep shale gas find after obtaining official government approval for proven geological reserves of 235.687 billion cubic meters in the Ziyang Dongfeng field in the Sichuan province. China Petroleum & Chemical Corporation, or Sinopec, as it is more commonly known, has announced that the Ministry of Natural Resources of China approved its reserves validation at the shale gas field, marking the creation of China's first ultra-deep, 100-billion-cubic-meter-level shale gas field. Sinopec has…