DEVELOPING TRENDS OF NATURAL GAS INDUSTRY AND THE SIGNIFICANT PROGRESS ON NATURAL GAS GEOLOGICAL THEORIES IN CHINA

The gas industry in China shows excellent developing trends: firstly, from country poor in natural gas to the one rich in it. In 2005, the gas output has reached near 500×10~8 m~3; secondly, the theory of natural gas exploration develops from monism(oil type gas-generating theories) to dualism(oil-type and coal-formed gas-generating theories); thirdly, the increasing gas output calls for strengthening in natural gas exploration and development. During the past more than 20 years, the natural gas geological theories have developed much: The coal measure source rocks mainly generate gas with minor oil; the identification index with high credibility and accuracy on various natural gases have been set up; the studies on the controlling factors of great gas field formation, by quantification or semi-quantification; the carbonate with TOC content about or lower than 0.2% can hardly be regarded as sources rocks and the TOC content of effective carbonate source rocks must reaches or more than 0.5%. Not only the abiogenic gas exists in the nature, but also can it form gas pools. Several CO 2 gas pools have been found in eastern basins of China. And the first abiogenic alcane gas reservoir in the world has been demonstrated by natural gas geochemistry.