Sichuan super gas basin in southwest China

A sedimentary basin is classified as a super basin when its cumulative production exceeds 5 billion barrels of oil equivalent (6.82x10(8) t of oil or 7931.66x10(8) m(3) of gas) and its remaining recoverable resources are at least 5 billion barrels of oil equivalent. By the end of 2019, the total output of oil and gas in Sichuan Basin had been 6569x10(8) m(3) with the gas-oil ratio of 80:1, and the total remaining recoverable resources reached 136 404x10(8) m(3), which makes it as a second-tier super basin. Because the output is mainly gas, it is a super gas basin. The reason why the Sichuan Basin is a super gas basin is that it has four advantages: (1) The advantage of gas source rocks: it has the most gas source rocks (9 sets) among all the basins in China. (2) The advantage of resource quantity: it has the most total remaining recoverable resources among all the basins in China (136 404x10(8) m(3)). (3) The advantage of large gas fields: it has the most large gas fields (27) among all the basins in China. (4) The advantage of total production: by the end of 2019, the total gas production had been 6 487.8x10(8) m(3), which ranked the first among all the basins in China. There are four major breakthroughs in natural gas exploration in Sichuan Basin: (1) A breakthrough in shale gas: shale gas was firstly found in the Ordovician Wufeng-Silurian Longmaxi formations in China. (2) A breakthrough in tight sandstone gas: the Triassic Xu2 Member gas reservoir in Zhongba gas field is the first high recovery tight sandstone gas reservoir in China. (3) A breakthrough in giant carbonate gas fields. (4) A breakthrough in ultra-deep gas reservoir. These breakthroughs have led to important progress in different basins across the country. Super basins are classified according to three criteria: cumulative production and remaining recoverable resources of oil and gas, tectonic attributes of the basin, and the proportions of oil and gas in cumulative oil and gas production.

Automated summary

The Sichuan Basin is classified as a super gas basin due to its abundant gas source rocks, large remaining recoverable resources, numerous large gas fields, and high total gas production.