The number of active drilling rigs in the United States increased by one to 255 rigs this week, down by 613 year on year, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes. These active drilling rigs included 179 oil rigs operating in the U.S. oil fields, down by one from the previous week; 73 gas drilling rigs, up by two from the previous week; and three miscellaneous rigs, unchanged from last week. The 255 rigs included 240 land drilling rigs, up by two from the previous week; 14 offshore drilling rigs, down by one from last week; and one inland water drilling rig, unchanged from last week.Of them, 23 are directional drilling rigs, 215 are horizontal drilling rigs and 17 are vertical drilling rigs. During the week, the number of drilling rigs decreased the most by three in the state of New Mexico to 43 rigs.By far, the Permian Basin in western Texas and eastern New Mexico has been the largest source of shale oil production growth in the United States, having become an engine of supply growth outside the Organization of the Petroleum Exporting Countries in the past years. The United States has become a major oil producer in the past years with the help of its shale oil production growth. Meanwhile, China continues to be one of the biggest oil consumers of the world. According to the latest release from the Chinese National Bureau of Statistics, China’s crude oil output increased 2.3 percent year on year to 16.65 million tonnes in August. China imported 47.48 million tonnes of crude oil in August, up 12.6 percent year on year.