The shale gas development has more than 3 decades of history. In China, the development is still in the early stage due the technology limitation. The estimated technically recoverable shale gas reserve is 882 Tcf in China. The predicted shale gas production in 2020 is 3.5 Tcf which will contribute 26% of natural gas consumption in China. In order to stabilize the gas output to meet the demand of economic development, increasing recoverable shale gas reserve becomes more and more important.
In this study, a Qiongzhusi reservoir was taken as an example to investigate the potential of shale gas in southern China. The methodologies involved in this investigation include experimental study on core analysis with Total Organic Content (TOC) and Vitrinite Reflectance, outcrops study, geostatistical analysis, and geo-modeling. Besides these methods, an irreplaceable step was to compare the reservoir conditions of given reservoir with successful developments in Barnett and Marcellus in the United States.
By integrating all above technologies and methods, the study forecasted the sedimentary facies, estimated shale gas distribution, and evaluated the petrophysical properties of the shale play. The result indicates that most of the Qiongzhusi reservoirs have promising thickness, favorable kerogen type (type I), high TOC, and encouraging maturity. This paper also predicted favorable zones in the middle and upper Yangtze area with properties of thickness more than 60 meters, TOC not less than 2.0%, and Vitrinite Reflectance from 2.5% to 4.6%.
The study would bring the reservoir engineers and geologists with detailed evidence to support the development of Qiongzhusi reservoirs, and furthermore, it offers the methodology to the research of other shale plays with similar properties.