In 2019, we added 103 million tonnes of proven oil reserve, 172 million tonnes of probable oil reserve and 200 million tonnes of possible oil reserve. For natural gas, the newly added proven reserve was 281.9 billion cubic meters, probable reserve was 157.6 billion cubic meters, and possible reserve was 344.2 billion cubic meters. The annual crude production was 35.13 million tonnes. We produced 29.6 billion cubic meters of natural gas, up by 2 billion cubic meters year on year. Our newly added crude oil production capacity was 2.615 million tonnes, increased by 212,000 tonnes year on year. Newly added natural gas production capacity was 3.97 billion cubic meters, up by 1.97 billion cubic meters.
We achieved 1 great breakthrough, 4 important breakthroughs, 10 new breakthroughs, 15 commercial discoveries and 5 potentials, which exceeded the annual tasks.
For oil exploration, significant breakthrough was made in Shunbei Block 3 area in Tarim Basin, which opened up the second production capacity in Shunbei oil and gas field. Such breakthrough was also made in the deep exploration of Jiyang depression in Bohai Bay Basin. Important commercial discoveries were made in the exploration of Yongjin oilfield in the middle of Junggar basin. New discoveries were made in the risk exploration of Liulushe area in Subei Basin.
For conventional gas exploration,an important breakthrough was made in the exploration of Paleozoic in Fuxian County in the south of Ordos Basin, with a proven reserves of exceeding 100 billion cubic meters in Dongsheng gas field to the north. The exploration results of tight gas in the deep layers of Sichuan Basin and Songliao Basin continue to expand; new breakthroughs were also made in the exploration of Wuyuanting lithological gas reservoir in the sea area.
For shale gas, a major breakthrough was made in the deep structural exploration in Dongxi, Qijiang of Sichuan Basin, and the exploration of atmospheric shale gas in Nanchuan realized discovery, exploration and construction in the same year.
We improved our construction scale for oil production capacity and reduced the decline rate of existing oil fields. We produced 6,000 tonnes of crude oil more than our annual plan.
For the new capacity, we added 50.51 million tonnes of reserve available for development. The one million-tonne production and construction project (phase I) in Shunbei oil and gas field was solidly pushed ahead. The construction and production scale of challenging reserves in Jiyang continued to expand. The integration of rolling assessment and construction in the west slope of Qintong depression was rapidly launched, and a breakthrough was made in the integrated test of geological engineering in Yongjin oilfield. The annual added production capacity reached 2.615 million tonnes, increased by 212,000 tonnes, and the new well oil production increased by 154,000 tonnes.
For the existing capacity, we strengthened the delicate description, fine water recovery and tapped potential meticulously, and made more efforts to stabilize production. The annual natural decline rate was stabilized at 10.3%, the natural decline rate of water- flooding reservoir was reduced by 0.5 percentage point, and the thermal recovery heavy oil and gas ratio was stabilized at 0.53. The gas-flooding method applied in Tahe carbonate fractured reservoir increased its new oil production by 800,000 tonnes, an increase of 90,000 tonnes year on year. We popularized application of large-scale EOR technology, implemented the demonstration project of heterogeneous composite flooding EOR, continued to promote the six pilot tests, focused on the optimization of existing recovery projects, and increased oil production through chemical flooding by 1.07 million tonnes in the whole year.
For conventional gas, we actively promoted the production capacity construction in Western Sichuan and other places, accelerated the rolling production construction in Heba, Zhongjiang, Longfengshan and other places, and continued to focus on the stable production of major gas fields such as Puguang, Yuanba, Daniudi, etc. We added 1.73 billion cubic meters production capacity annually, produced 21.88 billion cubic meters of gas, increased by 1.3 billion cubic meters year on year.
For shale gas, we actively promoted the production capacity construction of Fuling and Weirong shale gas fields, accelerated the rolling construction and production of shale gas in Nanchuan, and took the lead in promoting the three-dimensional development and adjustment of the existing area of Fuling shale gas field in China. We achieved a new annual shale gas production capacity of 2.2 billion cubic meters, produced 7.35 billion cubic meters of gas, up by 720 million cubic meters compared with last year.
For coal-bed methane, we steadily arranged our intricate development in Yanchuan South gas field, and achieved an annual gas output of 360 million cubic meters.